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					Building Technologies Program




             Industry Review: Low-Cost Cold Climate Solar Water Heating Roadmap


       Welcome to the Webinar! We will start at 11:00 a.m. Eastern Standard Time
                   Be sure that you are also dialed into the telephone conference call:
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                                       (If asked for a PIN #, press *0)
                  Download the presentation at http://www.buildings.energy.gov/webinars.html
  There will be a Q&A session at the end. Questions will be submitted electronically and answered verbally. Submit
 your questions by selecting “Q&A” on the menu at the top, click in the top box, type your question and click “Ask.”
Building Technologies Program                                                                               eere.energy.gov
Building Technologies Program



                                                Today’s Speakers

               Kate Hudon - Project Leader, National             Sean Ong – Energy Analyst, National
               Renewable Energy Laboratory (NREL)                Renewable Energy Laboratory (NREL)
               Ms. Hudon is a project leader in the              Mr. Ong holds a degree in physics from Seattle
               Residential Buildings Research Group at           Pacific University and began his career at NREL
               NREL. She is currently leading a low-cost solar   in 2008. Since then, Sean has published studies
               water heating project, with a research focus on   on topics ranging from the economics of
               affordable solar water heating solutions for      photovoltaic systems to land-use characteristics
               cold climates. Prior to this role, her research   of large wind farms. He focuses on technical and
               focused on evaluating emerging technologies,      economic analysis of solar energy systems, land
               which included an extensive laboratory            use requirements of large solar and wind
               evaluation of heat pump water heaters             facilities, and the impacts of retail rate structures
               (HPWHs).                                          on distributed generation.

               Bill Goetzler – Director, Energy Practice         Jay Burch – Senior Scientist, National
               Navigant Consulting, Inc.                         Renewable Energy Laboratory (NREL)
               Mr. Goetzler focuses on technology/market         Mr. Burch joined NREL in 1982. He has led the
               assessments and strategic planning for public     Low-Cost Systems Project for the development
               sector organizations, utilities, and              of low-cost, polymer-based residential solar
               manufacturers of products such as HVAC            domestic water heating systems at NREL since
               equipment, building controls, lighting, and       1997. He is also involved with the development
               renewable energy systems. Prior to joining        of modeling, optimization, and test methods for
               Navigant, he was an Associate Director at         residential and commercial buildings. Prior to
               Arthur D. Little, Inc., where he managed the      joining NREL, Jay worked at the Colorado
               HVAC and Building Energy Systems unit. He is      School of Mines as an assistant professor
               an AEE Certified Energy Manager and holds a       researching thermal modeling of buildings and
               B.S. from MIT and an M.S. from Stanford           measurement of heat transfer processes in
               University, in Mechanical Engineering.            buildings.
Building Technologies Program                                                                            eere.energy.gov
                       Webinar Objective and Agenda



                                                                                                            Low-Cost Cold Climate
                                                                                                            Solar Water Heating
                                                                                                            Roadmap Webinar

                                                                                                            Kate Hudon


                                                                                                            July 28, 2011




NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Webinar Objective

Main Objective of Today’s Webinar
      –		 Support the development of a roadmap for innovative low-cost solar
          water heating solutions in cold climates. NREL will submit the completed
          roadmap to DOE in September and its contents will provide guidance
          for low-cost solar water heating research going forward.

How to Achieve Objective
      –		 Gather Feedback from Webinar Participants
            •		 Q&A session – focused on opportunities and barriers to low-cost solar water
                heating solutions for cold climates.
            •		 Participant feedback will provide industry perspective that is key to guiding
                solar water heating research going forward.
            •		 Please submit written questions and comments throughout the
                webinar!

Long-Term Objective
      –		 Use the system development pathways in the roadmap to pave the way
          toward cost-effective solutions. These solutions would result in a healthy
          solar water heating market with significant market penetration.

NATIONAL RENEWABLE ENERGY LABORATORY
 Webinar Agenda

11:10am              Market Overview – Bill Goetzler, Navigant
                           • Current System/Installation Costs
                           • Market Penetration
                           • Competing Technologies

11:20am              Economic Analysis – Sean Ong, NREL
                           • Break-Even Maps

11:30am              Example Pathways from other Markets – Bill Goetzler, Navigant
                           • Existing Low-Cost Pathways in non-US Markets
                           • Technical and Market Gaps and Barriers

11:45am              Detailed Pathway Options – Jay Burch, NREL
                           • Requirements for Low-Cost Systems
                           • Polymer Option
                           • Glass Option
                           • Hybrid Systems

12:00pm              Q & A: Opportunities and Barriers to Innovative Solar Hot
                     Water Products for Cold Climates. Please submit your
                     questions!
NATIONAL RENEWABLE ENERGY LABORATORY
         Low Cost Solar Water Heating 

                   Webinar

       Market Overview and Examples from Other Markets





               July 28, 2011


              William Goetzler
              Director
              Navigant Consulting, Inc.
              Burlington, MA
              wgoetzler@navigant.com

©2011 Navigant Consulting, Inc.            0
                                                          ENERGY
Table of Contents





                                  1   Market Overview

                                  2   Examples from Other Markets




©2011 Navigant Consulting, Inc.                     1

                                                                    ENERGY
Market Overview » U.S. Solar Thermal Market › HŔŞşŚŝŔŎŌŗ TŝŐřŏŞ

      After 33% compound average annual growth (CAGR) prior to 1981, the
      U.S. market declined dramatically, and since 1991, CAGR has been 6%.
                                        Total U.S. Shipments of Solar Thermal Collectors
                          1,600                                                                                                    25,000
                                  33% CAGR                                                   6% CAGR




                                                                                                                                            Shipments (Thousands of sqft)
                          1,400
                                                                                                                                   20,000
                          1,200
       Shipments (MWth)




                          1,000                                                                                                    15,000

                           800

                                                                                                                                   10,000
                           600

                           400
                                                                                                                                   5,000
                           200

                             -                                                                                                     0
                                  1990



                                  1993
                                  1974
                                  1975
                                  1976
                                  1977
                                  1978
                                  1979
                                  1980
                                  1981
                                  1982
                                  1983
                                  1984
                                  1985
                                  1986
                                  1987
                                  1988
                                  1989

                                  1991
                                  1992

                                  1994
                                  1995
                                  1996
                                  1997
                                  1998
                                  1999
                                  2000
                                  2001
                                  2002
                                  2003
                                  2004
                                  2005
                                  2006
                                  2007
                                  2008
      *DŌşŌ ŝŐśŚŝşŐŏ Ŕř ęĘĘĘ’Ş Śő ŞŜƱőşƱ MWşœ ŔŞ ŎŌŗŎŠŗŌşŐŏ ōŌŞŐŏ ŠśŚř Ōř ŔřşŐŝřŌşŔŚřŌŗŗŤ ŌŒŝŐŐŏ ŠśŚř ŎŚřšŐŝŞŔŚř őŌŎşŚŝ Śő ĘƱğ ŖW th/m2.

      SŚŠŝŎŐƳ IřşŐŝřŌşŔŚřŌŗ EřŐŝŒŤ AŒŐřŎŤ’Ş SŚŗŌŝ CŚŚŗŔřŒ Ōřŏ HŐŌşŔřŒ PŝŚŒŝŌŘƲ SŚŗŌŝ HŐŌşŔřŒ WŚŝŗŏŢŔŏŐ 2008 Edition, Industry Interviews, 

      Navigant Consulting, Inc. based on data from Energy Information Administration, Solar Thermal Collector Manufacturing Activities 2008 & 

      Renewable Energy Annual. Annual installations domestic production and imports of low, medium and high temperature collectors.

      CAGR – Compound Annual Growth Rate



©2011 Navigant Consulting, Inc.                                         2
                                                                                                                    ENERGY
Market Overview » U.S. Solar Thermal Market › Value By Market Segment

      The hot water and heating market represents nearly 70% of the
      market value, but only 16% of the area of collectors shipped.

                                                   2008 Market Segmentation

          Area of Collectors                            Number of Systems                            Market Value by Use
           Shipped by Use                                Shipped by Use



             Pool Heating
                 84%                                         Pool Heating      Heating and                 Pool Heating
                                  Heating and
                                   hot water                   39-49%           hot water                    30-39%           Heating and
                                     16%                                         51-61%                                        hot water
                                                                                                                                61-70%



                                                                   Total number of                              Total Market Value
                 Total area shipped
                                                                   Systems shipped
                      17 mill Sq Ft                                                                              $260-$495 million
                                                                     64,000-82,000
      Source: Navigant Consulting, Inc. analysis based on data from: Industry Interviews, Energy Information AŏŘŔřŔŞşŝŌşŔŚř’Ş Solar 

      Thermal and Photovoltaic Collector Manufacturing Activities 2008 and Renewable Energy Annual, and internal analysis. 

      Note:    Pool Heating System size was assumed to be 350-400sqft; Non-pool heating systems were assumed to be 50-64 sqft.

               The dashed line represents the level of uncertainty in the calculations and should be considered as a range.



©2011 Navigant Consulting, Inc.                                          3
                                                                                                                     ENERGY
Market Overview » U.S. Solar Thermal Market › GŝŚŢşœ PŝŚŕŐŎşŔŚřŞ

      With optimistic U.S. market growth, the total value of the market
      could reach $2-4 billion later this decade.
                                                 Market Value Projection for the U.S. SWH Industry

                                        $4,000
                                                           BAU
                                        $3,500
                   Market Value ($MM)



                                                           High
                                        $3,000
                                                         CAGR 15%
                                        $2,500           CAGR 24%
                                        $2,000

                                        $1,500

                                        $1,000

                                         $500

                                           $0

                                                  2010    2011    2012   2013       2014   2015   2016   2017
                 Source: Navigant analysis.                                     Market Growth Assumptions
                 System Size: domestic SWH system 40sqft; Pool system 400 sqft; BAU: Pool CAGR 5%; other SWH CAGR 21%
                 BAU – Business As Usual; CAGR – Compound Annual Growth Rate High: Pool CAGR 8%; other SWH CAGR 32%



©2011 Navigant Consulting, Inc.                                                 4
                                                                                                                ENERGY
Market Overview » U.S. Solar Thermal Market › MŌşŐŝŔŌŗŞ Breakdown

      The value of the U.S. SWH market, including material and labor, was
      approximately $800MM in 2009. ~50% of the total value is material
      cost, which is dominated by collectors.
                                     Solar Water Heating – U.S. Component Values

                                           2009 SWH Component Market: $400MM

                                                      $44MM
                                                                                            Storage Tank
                                                   11%             $12MM
                                                                                            Heat exchanger and
                                                             3%
                                                                                            circulator system
                                                                        $36MM
                                                                                            Sensors & Gauges
                                                                9%
                                                                                            Valves
                                      51%
                                                                10%       $40MM             Tubing & Insulation

                                                                                            Collector and
                                                                                            Mounts
                                                        16%
                                                                $64MM
                                  $204MM

                    Source: RS Means, Navigant Consulting, Inc. based on data from Energy Information Administration, Solar Thermal and
                    Photovoltaic Collector Manufacturing Activities 2008 and Renewable Energy Annual and Industry Interviews.


©2011 Navigant Consulting, Inc.                                           5
                                                                                                                     ENERGY
    MŌŝŖŐş OšŐŝšŔŐŢ » GŗŚōŌŗ MŌŝŖŐş › SœŔśŘŐřşŞ

      China is the largest market for solar collectors, accounting for
      approximately 75% of global installations in 2008….
                          Newly Installed Solar Thermal Collectors in 2008, by Area
                                                                                              Greece
                                                                                                        Austria


                                                                                Other                               United
                                                                                                       France      Kingdom
                                                                                                                  Cyprus
                                                                                                                      Switzerland


                                                                                           Germany,
                    China, 75%         Europe, 12%                                           43%

                                                      United States
                                                        Turkey
                                                          Japan
                                                               Australia
                                                     Israel
                                                                      Brazil
                                           Other       India


         Source: International Energy Agency Solar Heating and Cooling Programme, Solar Heat Worldwide – Market and
         Contributions to the Energy Supply 2008, Edition 2010. May, 2010.




©2011 Navigant Consulting, Inc.                                            6
                                                                                                                      ENERGY
    MŌŝŖŐş OšŐŝšŔŐŢ » GŗŚōŌŗ MŌŝŖŐş › VŌŗŠŐ

      ….But Europe is the largest SWH market (in terms of revenue) with
      nearly half of global SWH market value.
                           2008 World Solar Water Heating Market Value: $12.4 billion


                                                                                                             Austria
                      World Market                                                               Greece

                      (in millions)                                                                                       United
                                                                                  Other
                                                                                                           France        Kingdom

                                                                                                                    Cyprus
                                                                                                                       Switzerland

                                                Europe, 49%
                                                                                              Germany, 42%
                 China, 22%




                     Other                                                                   European Market
        India
                                                                                               (in millions)
                  Israel            Australia
                                                          United States                      Total = $6 Billion
                           Brazil                Japan          Turkey

      Sources:
      1.	 NCI Analysis
      2.	 International Energy Agency Solar Heating and Cooling Programme, Solar Heat Worldwide – Market and Contributions to the
          Energy Supply 2008, Edition 2010. May, 2010.
      3.	 Sensors Report, 2008. http://www.mdpi.org/sensors/papers/s8021252.pdf



©2011 Navigant Consulting, Inc. 	                                         7
                                                                                                                    ENERGY
      Market Overview » High Efficiency Water Heating Systems › GŌŞ-Fired

Solar water heating competes with various types of gas-fired water heaters.

                                                     Gas Water Heating Options

  Conventional Gas Storage                              Condensing Storage                             Gas Tankless




                                                    AO Smith Vertex
Efficiency                 EF Ɓ ĘƱĞ ƽŞşŌřŏŌŝŏǼ    Efficiency                              Efficiency         EF > 0.82 (standard)
                                                                          EF ƅ ĘƱĠĘ
Rating                       EF ƅ ĘƱĞğ (HE)       Rating                                  Rating            EF Ɓ ĘƱġĠ ƽŎŚřŏŐřŞŔřŒǼ
Approximate               $800 to $1,000 (std.)   Approximate                             Approximate          $1500 to $3,000
                                                                       $2,000 to $3,000
Installed Cost           $1,200 to $1,500 (HE)    Installed Cost                          Installed Cost     (incl. new venting)

  ©2011 Navigant Consulting, Inc.                                  8
                                                                                                        ENERGY
      Market Overview » High Efficiency Water Heating Systems › EŗŐŎşŝŔŎ Ōřŏ SŚŗŌŝ TœŐŝŘŌŗ

Heat pump water heaters are a promising alternative to solar.

                                                   Electric Water Heating Options
Conventional Electric Storage                                   Heat Pump                               Solar Thermal




                                                     GE GeoSpring Hybrid Water
                                                     Heater, AO Smith Voltex

Efficiency                                         Efficiency                              Efficiency
                                      EF ƅ ĘƱġ                              EF ƅ Ě                                    SF ƅ ĘƱĝ
Rating                                             Rating                                  Rating
Approximate                                        Approximate                             Approximate
                                    $600 to $800                        $2,200 to $3,200                          $5000 to $10,000
Installed Cost                                     Installed Cost                          Installed Cost


  ©2011 Navigant Consulting, Inc.                                   9
                                                                                                         ENERGY
Market Overview » Solar Water Heating First Cost Comparison

Solar Water Heating systems are two to three times more expensive
than conventional high efficiency options.
                                        First Costs of Residential Water Heating Options
                 12,000

                 10,000                                                             Upper Bound
                                                                                    Typical
 Installed Cost [$]




                      8,000

                      6,000

                      4,000

                      2,000

                         0
                              Residential Gas Fired      Residential Electric      Residential Heat Pump              Solar Water Heater4
                                 Water Heater1        Resistance Water Heater2         Water Heater3

1. Source: EIA. Typical is 0.62 Energy Factor and Upper Bound is 0.85 Energy Factor. Both are 40 gallon capacity.
2. Source: EIA. Typical is 0.92 Energy Factor and Upper Bound is 0.95 Energy Factor. Both are 50 gallon capacity.
3. Source: EIA. Typical is 2.0 Energy Factor and Upper Bounds is 2.35 Energy Factor. Both are 50 gallon capacity
4. Solar Water Heating costs from Solar Hot Water Supply Chain Market Analysis, October, 2010. Variations in price due to variations in system
architecture. Cost shown is for a 40 gallon tank system before federal or local incentives.


©2011 Navigant Consulting, Inc.                                           10
                                                                                                                        ENERGY
Market Overview » What Incremental Costs for Competitiveness?

$500 to $1,000 incremental costs are needed for attractive Solar Water
Heating payback periods of 3 to 5 years.
               Solar Water Heating Incremental Costs Required by Location and Fuel Type

                                         8,000
                                                            Key
                                                                                                   Current Incremental Costs
                                         7,000       Boston
                                                     Chicago
                                                                                                   - Unsubsidized
              Incremental Cost [$2011]




                                                     Denver
                                                                               Current
                                         6,000
                                                     Los Angeles               Incremental Costs
                                         5,000       Miami                     – Subsidized
                                                     Gas        -------­
                                         4,000
                                                     Electric

                                         3,000

                                         2,000

                                         1,000

                                            0
                                                 0                         5             10                15            20             25
                                                                                      Simple Pay Back Period

          SŚŠŝŎŐƳ NŌšŔŒŌřşƲ ĚĘęę ŠŞŔřŒƳ SŤŞşŐŘ śŐŝőŚŝŘŌřŎŐ ŞŔŘŠŗŌşŐŏ ŠŞŔřŒ NREL’Ş SŤŞşŐŘ AŏšŔŞŚŝ MŚŏŐŗ őŚŝ Ō ěĚ ŞŜƱ őşƱ őŗŌş śŗŌşŐ ŎŚŗŗector
          ŞŤŞşŐŘƴ ŌřřŠŌŗ ŢŌşŐŝ œŐŌşŔřŒ ŏŐŘŌřŏŞ őŝŚŘ EIA’Ş ĚĘĘĝ RŐŞŔŏŐřşŔŌŗ CŚřŞŠŘśşŔŚř SŠŝšŐŤƴ Ōřŏ ŞşŌşŐŢŔŏŐ ŌšŐŝŌŒŐ ŐŗŐŎşŝŔŎ Ōřŏ ŒŌŞ
          rates from EIA. Federal Investment Tax Credit of 30% and $1,000 in local rebates (minus federal taxes) are the assumed subsidies.



©2011 Navigant Consulting, Inc.                                                               11
                                                                                                                               ENERGY
    Break-even Cost for Residential Solar
    Water Heating in the United States.


                                                                                                               Solar Water Heating
                                                                                                               Roadmap Webinar

                                                                                                               Sean Ong

                                                                                                               July 28, 2011




NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Quick Break-even definition



Break-even is when net present benefits = net present
costs.

“You neither save nor lose money”




NATIONAL RENEWABLE ENERGY LABORATORY                    2
 Key Assumptions

• System:
    • 40 ft2 collector
    • South facing at 26.5 deg.
    • 60 gal. solar tank, two-tank glycol active system
• Draw:
    • 64 gal/day, ASHRAE time profile*
    • Water heater set temperature of 120 F
• Simulation and Financial Assumptions:
    • System Advisor Model (SAM)
    • TMY3 Locations used for solar resource
    • 20% down payment, 30-yr home equity loan, 5% interest rate.




NATIONAL RENEWABLE ENERGY LABORATORY                                3
Fuels used for residential water heating





NATIONAL RENEWABLE ENERGY LABORATORY        4
Break-even maps (electric and natural gas)

             Electric                                     Natural Gas




                           Percentage of U.S. at or above break-even

                System cost            Electricity       Gas
                $7000                  16%               0.04%
                $5000                  51%               0.8%
                $2500                  94%               50%
                $1000                  100%
             95%
NATIONAL RENEWABLE ENERGY LABORATORY                                    5
   Break-even Fuel Prices





                    Electric                                         Natural Gas
• Only slight electricity price increases result in   • Substantial NG price increases are needed
a significant portion of the country at break-        for SWH systems to reach break-even. Even if
even.                                                 NG prices doubled, only 25% of the US would
                                                      be at break-even.




  NATIONAL RENEWABLE ENERGY LABORATORY                                                      6
Conclusions



• SWH systems need to drop below
$2,500 to be competitive with natural
gas prices in over 50% of the country.

• Achieving a price point of
$1,000/system would allow SWH to
be competitive with both electricity
and natural gas nearly everywhere.

• Increases in natural gas price –
even doubling – are not enough for
SWH systems to achieve widespread
parity with natural gas. System cost
reductions are necessary.




NATIONAL RENEWABLE ENERGY LABORATORY     7
                                       Thank You

                     Full analysis report can be downloaded at:
                     http://www.nrel.gov/docs/fy11osti/48986.pdf
                                       Authors:
                     Hannah Cassard, Paul Denholm, Sean Ong


                                            Contact:
                                       Sean.Ong@nrel.gov
                                         303-384-7451





NATIONAL RENEWABLE ENERGY LABORATORY                               8
                       Analysis Assumptions





NATIONAL RENEWABLE ENERGY LABORATORY           9
                       Break-even breakdown





NATIONAL RENEWABLE ENERGY LABORATORY           10
                       Break-even breakdown
                                                Breakeven SWH Cost ($/system) - Gas
                            HI
                           VT
                           LA
                           DE
                           GA
                           SC
                          OH
                           AZ
                           CT
                           CO
                           PA
                          MD
                           NC
                           NY
                          WV
                           AR
                            FL
                          MT
                           UT
                             RI
                          NM
                             IL
                           AL
                           OR
                          ME
                          MO
                           TX
                           KY
                          MA
                            ID
                            NJ
                           MI
                           VA
                           KS
                          MN
                           NH
                                                                                                  Gas Rate
                           WI
                           TN
                           DC
                           NV                                                                     Federal Tax Credit
                           OK
                          MS
                        CA No
                            IN                                                                    Tax Deductible Interest
                            IA
                        CA So
                          WY
                                                                                                  Local Incentives
                           SD
                           ND
                           NE
                          WA

                              -1000   0   1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 15000




NATIONAL RENEWABLE ENERGY LABORATORY                                                                                         11
Fuel Price Assumptions



  1.	 Utility fuel price data for 2008 from the EIA (flat rate
      only)
  2.	 Assumed real-price escalation of 0.5% per year for
      both electric and gas fuel prices
  3.	 Fixed charge adjustment of 6% for electricity, 2% for
      natural gas (removes fixed charges from fuel price)
  4.	 Base case scenario utilizes fuel price and solar
      resource location of the largest utility in each state




NATIONAL RENEWABLE ENERGY LABORATORY
System Parameter Assumptions

  1.	 Utilize default SAM solar water heating system (two-
      tank glycol w/ aux elec.) parameters for base case:
       1.	   Collector Tilt: 26.5 deg
       2.	   Collector Azimuth: 360 deg (south)
       3.	   Collector Area: 40 sf
       4.	   Storage Volume: 60 gal
       5.	   Water Heater Set Temp: 48.89 deg C
       6.	   FRta = 0.77, FRUL = 4.5 W/m2-C, IAM = 0.1, HX eff = 0.5
  2.	 System degradation of 0.5% per year
  3.	 Water heater energy factor for electricity of 90%,
      natural gas of 60%
  4.	 Natural gas burn efficiency of 80%
  5.	 TMY sites paired with electric utilities based on
      population center of the service territory
  6.	 Assume auxiliary system uses the same fuel as the
      current conventional system
NATIONAL RENEWABLE ENERGY LABORATORY
Usage Assumptions



  1. Single-family house
  2. Utilize default SAM load profile for all locations
  3. Favorable roof angle and orientation, not shaded





NATIONAL RENEWABLE ENERGY LABORATORY
Financing Assumptions



  1.	 Federal tax bracket: 28%
  2.	 Home-equity type loan, interest rate: 5%
  3.	 Loan period: 30 years
  4.	 Discount rate: 5%
  5.	 Evaluation period: 30 years
  6.	 Down-payment: 20%
  7.	 Federal ITC: 30%
  8.	 All state, local, and utility incentives from the DSIRE
      database included for each state
  9.	 O&M of $1000 at year 10 and year 20 for tank and
      heat exchange fluid replacement


NATIONAL RENEWABLE ENERGY LABORATORY
  Examples – Electric Break-Even


                                                                                    Base Annual
                Electric Price    State-Wide    Annual Value of    Base SWH Cost
    State                                                                          Average Solar
                (cents/kWh)        Incentives   Energy Saved ($)     ($/system)
                                                                                    Fraction (%)
    HI               27.3            $2,850          $539             $15,680           0.65
    NY               22.9            $1,500          $436             $11,540           0.61
    CT               18.0            $1,765          $335             $9,080            0.53
    CO                9.7            $3,000          $237             $7,685            0.71
   CA So             14.0              $0            $311             $6,675            0.80
    TX               12.4              $0            $287             $6,030            0.85
   CA No             12.4              $0            $277             $5,765            0.74
    FL               10.9             $500           $209             $4,425            0.86
    NE                7.6              $0            $148             $2,290            0.58
    MO                6.6             $500           $127             $2,240            0.62
    WA                8.9              $0            $145             $2,220            0.50


Break-even value is influenced by electric prices, local incentives, and available solar resource



  NATIONAL RENEWABLE ENERGY LABORATORY                                                      16
Components of Break-Even Cost - Elec

                                                                 Breakeven SWH Cost - Electric
                                    15000
                                                                                                             O&M Cost
                                    14000
                                                                                                             Local Incentives
                                    13000
                                                                                                             Tax Deductible Interest
                                    12000
                                                                                                             Federal Tax Credit
                                    11000
   Break-even SWH Cost ($/System)




                                                                                                             Electric Rate
                                    10000
                                     9000
                                     8000
                                     7000
                                     6000
                                     5000
                                     4000
                                     3000
                                     2000
                                     1000
                                       0
                                    -1000
                                            HI   NY CT DE   RI   VT CO MD PA MA NJ LA CA OH ME TX MT GA NH CA SC    IL   UT NV WI
                                                                                      So                   No

                                                                                  Top 25 States


NATIONAL RENEWABLE ENERGY LABORATORY                                                                                                   17
Components of Break-Even Cost - Elec

                                                           Break-even SWH Cost - Electric
                                    15000
                                                                                                         O&M Cost
                                    14000
                                                                                                         Local Incentives
                                    13000
                                                                                                         Tax Deductible Interest
                                    12000
                                                                                                         Federal Tax Credit
                                    11000
   Break-even SWH Cost ($/System)




                                                                                                         Electric Rate
                                    10000
                                     9000
                                     8000
                                     7000
                                     6000
                                     5000
                                     4000
                                     3000
                                     2000
                                     1000
                                       0
                                    -1000
                                            NM AZ MN MI AR DC FL OR NC AL MS ID WV VA SD WY IA OK IN ND KS TN KY NE MO WA

                                                                            Bottom 25 States


NATIONAL RENEWABLE ENERGY LABORATORY                                                                                               18
Examples – Gas Break-Even


                                                                                  Base Annual
               Natural Gas      State-Wide    Annual Value of    Base SWH Cost
 State                                                                           Average Solar
             Price ($/therm)     Incentives   Energy Saved ($)     ($/system)
                                                                                  Fraction (%)
  HI              $4.36            $2,850          $310             $9,505            0.63
  VT              $2.01            $3,000          $135             $4,935            0.51
  LA              $1.78            $3,000          $128             $4,765            0.74
  CO              $1.10            $3,000          $97              $3,920            0.70
  FL              $2.10             $500           $162             $3,175            0.86
  TX              $1.54              $0            $152             $2,400            0.95
 CA No            $1.36              $0            $118             $1,490            0.77
 CA So            $1.27              $0            $110             $1,285            0.82
  ND              $1.26              $0            $90               $735             0.55
  NE              $1.27              $0            $90               $720             0.58
  WA              $1.32              $0            $77               $390             0.49



Break-even value is influenced by natural gas prices, local incentives, and available solar
                                       resource


NATIONAL RENEWABLE ENERGY LABORATORY                                                      19
Components of Break-Even Cost - Gas

                                                             Breakeven SWH Cost - Gas
                                     15000
                                                                                                           O&M Cost
                                     14000
                                                                                                           Local Incentives
                                     13000
                                                                                                           Tax Deductible Interest
                                     12000
                                                                                                           Federal Tax Credit
                                     11000
    Break-even SWH Cost ($/System)




                                                                                                           Gas Rate
                                     10000
                                      9000
                                      8000
                                      7000
                                      6000
                                      5000
                                      4000
                                      3000
                                      2000
                                      1000
                                        0
                                     -1000
                                             HI VT LA DE GA OH CO SC AZ CT UT PA MD NC MT WV NY OR AR RI     FL   IL   ID MI ME

                                                                             Top 25 States


NATIONAL RENEWABLE ENERGY LABORATORY                                                                                                 20
Components of Break-Even Cost - Gas

                                                              Breakeven SWH Cost - Gas
                                     15000
                                                                                                         O&M Cost
                                     14000
                                                                                                         Local Incentives
                                     13000
                                                                                                         Tax Deductible Interest
                                     12000
                                                                                                         Federal Tax Credit
                                     11000
    Break-even SWH Cost ($/System)




                                                                                                         Gas Rate
                                     10000
                                     9000
                                     8000
                                     7000
                                     6000
                                     5000
                                     4000
                                     3000
                                     2000
                                     1000
                                        0
                                     -1000
                                             NM NJ MA KY AL MO MN TX WI NH VA KS DC TN NV OK MS CA IN WY IA CA SD ND NE WA
                                                                                                No          So

                                                                             Bottom 25 States

NATIONAL RENEWABLE ENERGY LABORATORY                                                                                               21
Examples – Negative Break-Even Gas

                             Annual      O&M in                 NPC of O&M    Net
                Gas Price                          NPB of Gas
    State                 Value of Gas year 10 and             and downpay. Present
               ($/therm)                           Savings ($)
                           Savings ($) year 20 ($)                  ($)     Value ($)
     OH           $1.73     $105.18      $1,000      $1,613        $1,991    -$378
     CO           $1.10      $96.91      $1,000      $1,486        $1,991    -$505
     MT           $1.38     $105.31      $1,000      $1,615        $1,991    -$376
     UT           $0.93      $74.89      $1,000      $1,148        $1,991    -$843
      IL          $1.37      $91.66      $1,000      $1,405        $1,991    -$585
     OR           $1.37      $82.06      $1,000      $1,258        $1,991    -$733



  States with low natural gas prices or low energy savings have a negative net present 

  value before incentives. The cost of operating the system is greater than the value of 

                                     the gas savings.




NATIONAL RENEWABLE ENERGY LABORATORY                                                    22
Table of Contents





                                  1   Market Overview

                                  2   Examples from Other Markets




©2011 Navigant Consulting, Inc.                     1

                                                                    ENERGY
Examples from Other SHW Markets » Overview
U.S. SWH systems are much more expensive than Israeli or Chinese systems, driven by 

different system types, specifications, quality, installation factors, and market volume. 


    Characteristics                       United States                                Israel                                China
 Typical Installed Cost            $5,000-10,000                            $1,000-1,800                         $300-1,000
 (domestic, 2-4 people)
 Most Common                       Indirect                                 Thermosiphon                         Thermosiphon
 Technology                        (with pump)                              (no pump)                            (no pump)
 Tank Capacity                     80 gal                                   ~30 gal                              30-50 gal
 Collector Sizes                   ~50 sqft total                           ~20 sqft total                       ~20 sqft total
 Backup System                     Conventional electric/gas                Electric heating element             Electric heating element
 Quality                           Highest. SRCC certified                  High. Some are SRCC                  Low. Many not certified
                                                                            certified                            Shorter system life.
 Typical Installation              Collectors on pitched roof.              Collectors and tank on               Collectors and tank on
                                   Indoor tank. Complex                     flat roof. Simple system.            the roof (some flat, some
                                   design. Building not                     Building designed for                pitched). Simple system.
                                   designed for SWH.                        SWH. Experienced                     Experienced installers.
                                   Limited SWH experience.                  installers. Medium labor             Low labor costs.
                                   High labor costs.                        costs.
 Market Volume                     30,000 installs/year                     70,000 installs/year                 6,000,000 installs/year
Sources: Israel: Amcor, Pro, Tovtoda. China: Changzhou Erjin Solar Energy Equipment Co., Zhejiang Shentai Solar Energy Co., Changzhou He Jia
Solar Energy Co.,China Verysolar Technology Co.,Haining Oupairineng Solar Water Heater Co., Beijing Sunpu Solar, Linuo Ritter International
(China-Germany JV), Tecco Group. U.S.: Butler Sun Solutions, A.O. Smith, Caleffi, Solahart, Solene/ Chromagen, Alternate Energy Technologies, Fafco,
Silicon Solar, SunEarth, Inc., TCT Solar. U.S. costs confirmed against California Solar Initiative. All: IEA Solar Heat Worldwide 2010.
CSI-Thermal Program reported costs and HECO: 2007, Ron Richmond.
©2011 Navigant Consulting, Inc.                                         2
                                                                                                                    ENERGY
Examples from Other SHW Markets» Price Comparison by System Type

Across all technology types, U.S. SWH systems are significantly more
expensive than similar systems in China and Israel.
                  SWH Typical Installed System Price                        •	 Thermosiphon is the most common
                                                                               configuration in Israel and China.
                  $8.0                  China
                  $7.0                  US                                  •	 Continental U.S. typically uses
                  $6.0                  Israel                                 indirect and direct systems.
   Thousand USD




                  $5.0
                                                                            •	 Thermosiphon system is used in
                  $4.0                                                         Hawaii, where freezing is not a
                  $3.0                                                         concern.
                  $2.0
                                                                            •	 Thermosiphon is the least expensive
                  $1.0                                                         SWH system configuration, but even
                  $0.0
                                                                               U.S. thermosiphon systems are far
                                                                               more expensive that Chinese or
                            Direct*     Thermosiphon        Indirect
                                                                               Israeli units.
                                      Technology Type
                         Incentives not included in system costs.
 Sources: Israel: Amcor, Pro, Tovtoda. China: Changzhou Erjin Solar Energy Equipment Co., Zhejiang Shentai Solar Energy Co., Changzhou He
 Jia Solar Energy Co.,China Verysolar Technology Co.,Haining Oupairineng Solar Water Heater Co., Beijing Sunpu Solar, Linuo Ritter
 International (China-Germany JV), Tecco Group. U.S.: Butler Sun Solutions, A.O. Smith, Caleffi, Solahart, Solene/ Chromagen, Alternate Energy
 Technologies, Fafco, Silicon Solar, SunEarth, Inc., TCT Solar, Solar Water Heating Supply Chain Market Analysis for the City of Milwaukee,
 Navigant Consulting 2010. U.S. costs confirmed against California Solar Initiative CSI-Thermal Program reported costs and HECO: 2007, Ron
 Richmond.
 *Direct systems are uncommon in China and Israel.
©2011 Navigant Consulting, Inc. 	                                      3
                                                                                                                    ENERGY
         Examples from Other SHW Markets» Detailed Price Comparison for Typical U.S./Israeli Systems

        A detailed cost comparison of U.S. and Israeli systems reveals many design
        differences, which impact both material and installation costs.
                                 Elements of Total Installed Cost of Typical U.S. and Israeli Systems
                                                                                                                                  Pressurized Tank*
                $8.0
                                                                                                                                  Building Not SWH-Ready
                $7.0
                                                                                                                                  Indoor Tank Installation
USD Thousands




                $6.0                                                                                                              Pitched Roof Installation
                $5.0                                                                                                              Lower Collector Mfg Volume

                $4.0                                                                                                              Larger Collectors*
                                                                                                                                  Conventional Backup*
                $3.0
                                                                                                                                  Larger Tank*
                $2.0
                                                                                                                                  Other U.S. Cost Elements
                $1.0                                                                                                              Base Cost
                $0.0                                                                                                              Israeli Prices
                         Israel Thermosiphon U.S. Thermosiphon            Israel Indirect        U.S. Indirect (Most
                                                                                                                               Incentives not included
                            (Most Common)                                                             Common)
                                                                                                                               in system costs.
 Other U.S. Cost Elements: Higher quality/more features, less installation experience, higher labor rates,
less installer competition, higher installer overhead/marketing costs, and higher installation costs associated
with the asterisked material costs in the bar chart.
Sources: Israel: Amcor, Pro, Tovtoda. China: Changzhou Erjin Solar Energy Equipment Co., Zhejiang Shentai Solar Energy Co., Changzhou He Jia Solar Energy Co.,China
Verysolar Technology Co.,Haining Oupairineng Solar Water Heater Co., Beijing Sunpu Solar, Linuo Ritter International (China-Germany JV), Tecco Group. U.S.: Butler Sun
Solutions, A.O. Smith, Caleffi, Solahart, Solene/ Chromagen, Alternate Energy Technologies, Fafco, Silicon Solar, SunEarth, Inc., TCT Solar, Solar Water Heating Supply Chain
Market Analysis for the City of Milwaukee, Navigant Consulting 2010. U.S. costs confirmed against California Solar Initiative.
CSI-Thermal Program reported costs and HECO: 2007, Ron Richmond. All: IEA Solar Heat Worldwide 2010.
          ©2011 Navigant Consulting, Inc.                                           4
                                                                                                                                      ENERGY
Examples from Other SHW Markets» Policy Impact on Price

SWH policies vary across countries and greatly impact actual installed 

system prices, but US direct financial incentives are the most generous.


                          U.S.                                  Israel                                    China
 • The federal government                           • SWH systems were                        • Under the national “Getting
   offers a 30% investment tax                        mandated in new                           Household Appliances into
   credit on SWH systems.                             construction of                           the Countryside” initiative,
 • State and utility rebates vary                     residential buildings                     up to 13% of system costs
   from $500/system                                   after 1980. A number                      can be subsidized for rural
   (Snohomish County PUD No                           of pre-1980’s                             customers (up to ~$80 USD).
   1 - Solar Express Rebate                           buildings also have                     • Local programs, such as the
   Program) to a maximum of                           SWH installations.                        one in Beijing, have invested
   $5,000/system (Pennsylvania                                                                  up to $30M for SWH
   Sunshine Solar Rebate                                                                        subsidies (~$10/system).
   Program).                                                                                  • Golden Sun Certification is
 • Additionally, the state of                                                                   not mandatory to
   Hawaii benefits from state,                                                                  manufacture or sell SWH in
   local, and utility rebates that                                                              China, leading to variance in
   can reduce the average                                                                       product quality. As of March
   installed cost by over 2/3.                                                                  2011, only 30 of ~40,000 SWH
 •The State of Hawaii also                                                                      manufacturers have earned
  mandates that all new homes                                                                   this certification.
  are built with SWH systems.

 Source: HECO, U.S. Department of Energy, Israeli Department of Science and Technology, China Golden
 Sun Program, DSIRE Solar Incentive Database
©2011 Navigant Consulting, Inc.                                      5
                                                                                                           ENERGY
Examples from Other SHW Markets» Conclusions

Many factors contribute to the higher cost of U.S. SHW systems relative to
Israel and China, but there are many misperceptions about their impact.
     Cost Factor                  Impact                        Explanation for Higher U.S. Costs
                                            The indirect system, which is the most common U.S. system type, is more expensive
 Technology Choice                 High     than the thermosiphon system, which is the dominant configuration in China and
                                            Israel.
                                            More complex systems with higher quality materials and additional features drive
 Design                            High
                                            higher material and installation costs.
 Building SWH                               Buildings in Israel are designed to be SWH-ready, significantly reducing labor and
                                   High
 Preparation                                material installation costs.

                                            Inexperience, higher overhead/marketing, less standardization, and less competition
 Installer Costs                   High
                                            contribute to higher installation cost.

                                            U.S. systems use double the collector area and storage tank capacity to meet U.S. hot
 System Capacity                  Medium
                                            water capacity expectations
                                  Medium/   Higher labor rates increase installation costs, but they have a relatively small impact
 Labor Rates
                                   Low      on total costs relative to Israel.
                                  Medium/   Chinese system quality is inferior but Israeli systems are certified to US and
 Quality
                                   Low      European standards.
 Manufacturing                    Medium/   Lower U.S. manufacturing volumes relative to both countries has a modest impact on
 Volume                            Low      total cost, as it impacts primarily collector costs, and Israeli market is not so large.
 Pressure                                   U.S. end-users expect hot water at a high and steady pressure, necessitating
                                   Low
 Requirements                               pressurized systems, but expectations are less stringent in China and Israel.

 Incentives/Rebates                N/A      U.S. incentives are far more generous than those in China and Israel.


©2011 Navigant Consulting, Inc.                                    6
                                                                                                          ENERGY
    Cold-Climate Solar Water Heaters:
    Pathways to Cost Reduction


                                                                                                               Low-cost Solar Water
                                                                                                               Heater Roadmap Webinar

                                                                                                               Jay Burch

                                                                                                               July 28, 2011




NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Presentation outline


• Solar          water heater costs
            • Cost goals and system characteristics goals


• Potential pathways to low cost
            •   General strategies
            •   Polymer components
            •   Evacuated tube collectors
            •   Hybrid approaches


• Conclusions
            • Practical pathways exist for significant cost reduction




NATIONAL RENEWABLE ENERGY LABORATORY                                    2
  Cost goals


• Installed cost goal range: ~$1K - $3K
   – Makes SWHs competitive with natural gas and HPWHs



• Current SWH cost range: ~$5K - $10K
   – Significant cost reduction needed: 2X to 4X
   – Current technology is mature    significant reductions unlikely


                                        Challenging!!




 NATIONAL RENEWABLE ENERGY LABORATORY                             3
Cost categories


      Total SWH cost = First cost + Maintenance cost

• First Cost = hard costs + soft costs

      – Hard costs: inherent, unavoidable costs
            •   Hardware, Installation: (~$3K-$5K today); addressable through R&D

      – Soft costs: external, potentially avoidable costs
            •   Marketing; permits, inspections, paperwork:(~$2K -$5K today);
            •   Not addressed here, but need to be lowered drastically

      – Interactions lowering first cost
            •   Low-cost systems easier to market    lowered market cost
            •   Lowered-weight /volume     lowered installation cost + more-efficient market channels



• Maintenance Cost: inherent, depend on design (0.3% – 3% of hardware cost/yr)


NATIONAL RENEWABLE ENERGY LABORATORY                                                                    4
Other relevant low-cost SWH goals

• High energy savings:
            Maintain savings at current levels, ~ 60% solar fraction (SEF ~ 2.2)
• High reliability:
            Minimal maintenance; no degradation/failures from stagnation or freeze
• Good aesthetics:
            Mount collector flush, no visible tank


• Lifetime: marketing question
            10-20 years (vs. current systems 10 - 50 years, f(maintenance) )
• Low weight and volume
            Enables “on-the-plumber’s truck” and big-box market channels




NATIONAL RENEWABLE ENERGY LABORATORY                                               5
General cost reduction strategies


• Substitute less-expensive components
            • Collectors, pipes, tanks, valves


• Eliminate components: simplify system
            • Reduced part count     increased reliability
            • Example: cold-climate thermosiphon system


• Re-think the system
            • Hybrids: combine technologies?




NATIONAL RENEWABLE ENERGY LABORATORY                         6
Specific examples


• Polymers:
            Component substitution: glycol system
            Part elimination: thin-film thermosiphon


• Dewar-type evacuated tubes:
            Component substitution: Double-wall evacuated tube collectors


• Hybrid systems:
            System re-thinking: solar-assisted heat pump




NATIONAL RENEWABLE ENERGY LABORATORY                                        7
   Polymer path: glycol system example
                                                                                                                                          Film-lined storage
Polymer Collector                                                                                                                                  Heat exchanger

                                                                                                                                                     Retainer ring
                                                     Cost & Cost-of-Savings/ Glycol                                                                   Submersible pump


                                   $3,500                   [COSE = (Cost)/(Savings)]                                 12                              Polymer film liner

                                                                                                         1st Cost
                                                                                                         COSE
                                   $3,000
                                                                                                                      10                              Insulation




                                                                                                                           COSE [c/kWh]
                                                                                                                                                      Sheet metal cylinder
                      First Cost



                                   $2,500
                                                                                                                                                      Rigid foam base
                                                                                                                      8

                                   $2,000


                                                                                                                      6
                                   $1,500
                                                                                                                                          Polymer heat exch.
                                                        BOS Variations                  Collector Variations
                                   $1,000                                                                             4

                                              se      um
                                                        p
                                                            +h
                                                                 x      g
                                                                    ipin cka
                                                                             ge tl-    gls   ctiv
                                                                                                  e
                                                                                                      ctiv
                                                                                                           e     ed
                                            ca                                                               laz
Eliminate tank pump                   se          e p ta nk ed p         pa      e m      ele -sele ung
                                    Ba         On er         rat     lve    ctiv     er
                                                                                        s       n        r
                                                    ym Integ       Va -se le olym            no lyme
                                                 ol                                       er        o
Integrated valve package                       P
                                                                     No
                                                                        n      P
                                                                                   Po
                                                                                     l ym        P

pkg
Integrated PEX piping

                                                                                                                                                              Cost ~$12
  2003 cost study

  NATIONAL RENEWABLE ENERGY LABORATORY                                                                                                                             8
   Thermosiphons: an inherently lower-cost system

                                                                                            Ameliorating the
          Advantages                                 Disadvantages
                                                                                             disadvantages
Lower cost                                 Roof weight                               Place storage at roof peak
  (no circulation hardware, ~$250)            (~ 500 lbs)                              (lowers moment, need to re-inforce)
More reliable, simpler                     Pipe freeze                               Use pipe freeze protection/PEX
  (no pump, controller, sensors to fail)      (potable water piping in attic)          (PEX will not burst on freeze: fail-safe)
Maintains high performance                 Aesthetics                                Place storage out of sight
  (~96% of a glycol system)                   (bulbous tank visible on roof, typ.)     (place inside attic at peak,...)




                                      Tank



                                             Pipes



 Collector




  NATIONAL RENEWABLE ENERGY LABORATORY                                                                                    9
  Polymer path2: Seam-welded thin film thermosiphon



                                                      Seam weld pattern




                  Collector              Storage (hx not shown)




     High-speed roll-to-roll
     fabrication possible




Furnished by RhoTec; patented
  NATIONAL RENEWABLE ENERGY LABORATORY                                    10
  Prototype test units




  Healdsburg
                                         Phoenix

                                                   San Francisco
Furnished by RhoTec
  NATIONAL RENEWABLE ENERGY LABORATORY                             11
  Dewar-type evacuated tube collectors/systems

                    2-wall dewar design,
                    w/ thermosiphon hx
Evacuated space
                                                            Hot out
Selective coating
                       Hot water out
                                                                             Cold in
                       Cold water In

                                                                 Double-wall tube
   Glass tube

                Tube cross-section                          Tube-in-tank side view

 Evacuated tubes are an elegant combination of low-cost tube manufacturing
 with high-tech solar coatings, combining low cost and high performance.

                                        < $5/ft2-absorber

 NATIONAL RENEWABLE ENERGY LABORATORY                                                  12
 Evacuated Tube Thermosiphons

                                            Evacuated
                                            tube                   Storage tank
                                            collector


                                                                                        Mixing
                                                                                        valve

                                                                 PEX piping




                                                  Hot                         Cold
                                                  out                         in


                                                                                     Capillary tube
                                                                                     limiting flow




Porcupine-style thermosiphon: unsuitable      Remote-coupled thermosiphon: suitable for
for the U.S. residential market (poor         the U.S. residential market, with a freeze
aesthetics and no pipe freeze protection)     protection approach indicated


NATIONAL RENEWABLE ENERGY LABORATORY                                                        13
Hybrid Systems: Solar-assisted heat pump
                                       No solar storage;
                                       both heat pump and
                                       collector run all day

                                       Air or liquid collector
                                       and heat exchanger

                                           Heat to                          ~Expected COP with solar
                                           evaporator
   Collector

                                                Evaporator
                                                                 8

                                                Compressor




                                                                 COP
                                                Condenser

                                                                 1
                                Tank                                   60
                                                                             T_tank_hx [F] 120

                            Heat pump                                              ~75% COP increase at
                            water heater                                           operating point

NATIONAL RENEWABLE ENERGY LABORATORY                                                               14
Support for industry-driven SWH R&D
                              DOE-funded support provided via:
                              • National labs (NREL, Sandia)
                              • Universities (Minnesota, others)
                              • A&E firms



Component/system modeling                           Materials selection and testing
Component/system testing




 Collector/system test stand, NREL
                                                          UV-weathering capabilities, NREL



 NATIONAL RENEWABLE ENERGY LABORATORY
Conclusions


• Practical low-cost SWH designs exist that reach cost goals
            • Component substitutions; system simplification; re-design
            • Small R&D investment/speed to market in some paths (engineering
              only)
            • Soft costs must be considered to reach goals


• Key technical challenges:
            •   If new materials used     long-term durability testing
            •   Low-cost heat exchangers for unpressurized tanks
            •   If films chosen   identify/develop long-lived glazing/absorber films
            •   Overheat/freeze protection: choose options, optimize, verify




NATIONAL RENEWABLE ENERGY LABORATORY                                               16
End of Webinar Pathways Discussion




  Please submit comments and questions

        Additional slides follow in Appendix as background information




NATIONAL RENEWABLE ENERGY LABORATORY                                     17
System Metrics Used

  Annual system efficiency (ηann):
             • ηann = Qsaved/Qincident
                         Qsaved = Qann,aux, no solar – Qann, aux, with solar
                         Qincident = Acollector *Hsun,year,coll




 Levelized cost of saved energy (Csav):
             • Csav = (Total cost)/(Total savings)
                         Total cost = (Total first cost) + (PresentValue of O&M cost)
                         Total discounted savings = PresentWorthFactor*Qsaved ,ann




 Simple payback (SP):
             • SP = ($first cost)/($saved/year)
                         $first cost = Hardware + Install + Soft Costs
                         $saved/year = $energy*Qsaved,ann/ηconv




NATIONAL RENEWABLE ENERGY LABORATORY                                                    18
Account for performance reductions
    Annual efficiency is ~ constant
                 for a given system and draw volume
    Annual efficiency varies from ~38% (best collector) to ~22% (unglazed)
                   for 40 ft2/60 gal system with 64 gal/day draw



                                             Glycol Solar System
                              45%                                                  Selective
                                                                                   Nonselective
                                                                                   Polymer
                                                                                   Unglazed
                              35%
                 Efficiency




                              25%




                              15%
                                    0             10                      20                  30
                                                Annual Average Temperature (C o)




NATIONAL RENEWABLE ENERGY LABORATORY                                                               19
Schematic Glycol System

                                       Indirect two-tank system
                                          w/ Immersed heat exchanger
                                          Most common retrofit system




NATIONAL RENEWABLE ENERGY LABORATORY                                    20
Thermosiphon vs. Active: Much simpler

        Thermosiphon                                                   Active
                                                                                       Collector sensor
 Solar tank
                                    Cold In
                                                             Cold In

                                                                                Wires

                                              Hot Out                                                    Pump
       Hot Out


                                                              Inside                        Controller
                                                            Solar tank
                                          Elec.                          Tank sensor                      AC Power
                                          tank

Thermosiphons:                                          Extra hardware vs. thermosiphon
        • Fewer parts, less cost
        • More reliable
        • ~Equal performance with active
        • No interior space needed for solar tank
 NATIONAL RENEWABLE ENERGY LABORATORY
   Hybrid Systems: PV Thermal

                                                    Fan
                                                          Vents to hx
                                 Air-to-liquid hx


                                                                        Air collectors above
                                                Pump

Ambient air in
                                Water
                                heater                         PV panels below




        Solar water heating can
        be added to a PV                                         Ambient air in
        system inexpensively

                                                                              Echo-first system
  NATIONAL RENEWABLE ENERGY LABORATORY                                                    22
Summary and Next Steps

     Webinar Summary
          –		 Presented need for solar water heating innovation that results in
              large scale market penetration.
          –		 Reviewed foreign markets and how they compare to the U.S.
              market.
          –		 Gave examples of possible pathways to low-cost systems.


     Next Steps
          –		 Gather input.
          –		 Develop roadmap to provide guidance for low-cost solar water
              heating research going forward.
                •		 First draft of roadmap will be released for open peer review in August.
                •		 Final roadmap submitted to DOE in September.
          –		 NREL’s long term goal is to work with industry to facilitate cost-
              effective solar water heating solutions with the potential for
              significant market penetration.

NATIONAL RENEWABLE ENERGY LABORATORY
Conclusion


     Thank you for attending the Low-Cost Solar Water Heating 

                             Webinar!



 Please send additional comments and questions to Kate Hudon 

                    at kate.hudon@nrel.gov.



   Regular updates and background materials will be posted on:

     https://sites.google.com/site/solarhotwaterinnovation/





NATIONAL RENEWABLE ENERGY LABORATORY
Building Technologies Program




                                 Question and Answer Session
                                Questions will be submitted electronically and
                                     answers will be provided verbally

        To submit a question, select Q&A on the top bar, click in the top box, type
                                  your question, click Ask
                                     For a copy of today’s slides, visit
                                http://www.buildings.energy.gov/webinars.html.

Building Technologies Program                                                    eere.energy.gov
Building Technologies Program




                           Thank you for attending the webinar

 If you have any additional questions for our presenters, please email Kate Hudon at 

                                kate.hudon@nrel.gov. 

                 Visit http://www.buildings.energy.gov/webinars.html to download 

     today’s presentation and to register for announcements of upcoming webinars.



Building Technologies Program                                                        eere.energy.gov

				
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