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eventENERGYMeeting_August_2009

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  • pg 1
									Making Solar Simple
    Solar Thermal History in North America
1891 – First patented solar water heating device
1900s – Regional growth in sunny areas
        1920s – LA Natural gas discovery ended California market 
      – 1920s – LA Natural gas discovery ended California market
      – 1941 ‐ Half of Miami homes had Solar Water Heaters, then 
        low electric rates withered market
1974 and 1979 – Arab oil embargos
1974 d 1979 A b il         b
     Rapid growth replaced conventional energy sources
     Government subsidies fueled boom
     200+ solar panel manufacturers
1986 – Cheaper fossil fuel, ceasing of subsidies, inferior 
  equipment lead to end of “first” solar era
By 1995 – Most systems failed, were abandoned, or were 
  removed   
  removed
                                                               2
Seasonal Effects of Sun’s Energy




                                   3
70% of Solar Energy Comes from the
         Middle 6 Months
                             Average Daily Solar Energy Striking Solar Panel  
       60,000 

                                                        14% 
                                                        14%    14% 

       50,000                                   12% 
                                                                       12% 


       40 000
       40,000                            10% 
                                         10%

                                                                                 9% 
BTUs




                                 8% 
       30,000 

                                                                                       6%
                                                                                       6% 
                       6% 
       20,000 
                 4%                                                                          4% 
                                                                                                   3% 
       10,000 
       10 000




           ‐
                            US Solar Map
         63%


                                 73%            61%

            102%
      98%                 100%
                   112%
        96%




                                               86%




Colorado’s solar resource:
The short answer: It is really, really good!
Average Daily Solar Radiation
          Btu/sqft day
          Btu/sqft*day




                 45 deg panel tilt, Hay and Davies model   6
Solar Demand Comes From All 
          Regions
          R i




                           7
          Technology Overview
          Technology Overview
• Passive Solar Heating ‐ easy, beautiful, elegant
• Solar Hot Water – heating and hot water 
  “Thermal” measured in “ ” “ h
  “ h    l”                          ”
                   d “Btu” or “therms”
                  electricity 
• Photovoltaics – electricity
    “PV” measured in “kilowatt hours”
• Synergistic Effects – working together 
             Passive Solar Space Heating

In Winter: Sun shine
enters through south
windows warming space

In Summer: Roof
overhang limits solar
g
gain

Doesn’t incorporate
fans or circulators




                                           9
             Solar Thermal Diagram




From http://powertomorrow.com
     Active Solar Thermal Systems
     Active Solar Thermal Systems
                           Flat Plate




Incorporate a pump to move
liquid through system.
li id th     h    t

Use either:                       E     t d Tube Pl t
                                  Evacuated T b Plate
     “flat plate collector” or
     “evacuated tube collector”



                                                        11
• Collect
  Store
• St
• Move
• Control
Slide 12

A1         Author, 8/19/2009
   Active Solar Thermal Systems




Jenni Energietechnik AG




                                  13
Active Solar Systems  
    Caleffi Lab  ‐ Italy
              3 Categories of
        Active Solar Thermal Panels
Low Temperature Panels
  Swimming Pools


Medium Temperature Panels
  Hot Water Heating
                           oday s ocus
                          Today’s Focus
  Space Heating


High Temperature Panels
Hi h T           P   l
  Industrial and Chemical processing


                                          15
Solar Swimming Pool Panels




                             16
                     Flat Plate Collectors
Most common collector in 
North America

Absorber plate is principle 
   p
component
  Made of copper sheet
  and tubing
  “Selective surface”
  absorbs majority of
  solar radiation




                                             17
Flat Plate Detail




                    18
              Evacuated Tube Collectors
Glass tubes with
concentric inner and
outer walls
Acts like a Thermos
bottle
Coated copper
absorber plate in
inner glass
Specialized fluid
sealed within



                                          19
                   Typical Evacuated Tube Heat 
                            Transmitter
                            T     i



Critical detail to transfer heat




                                                  20
Flat Panel versus Evacuated Tube
     Which Performs Better? 
                  Factors
  Freeze Protection Method Used
  Shipping, Handling and Installation Ease
  Heat Load: Space Heating or Hot Water?
  Roof Area Requirements
  Maintenance Requirements
  Ability To Shed Snow
  Cost of Equipment
  Thermal Efficiency  

                                             21
          Flat Plate                 Evacuated Tube

• More efficient in temperate   • More efficient in very cold,
  climates                        cloudy climates
• Can be architecturally        • Can produce higher water
  integrated into roofs more      temperature – space
  easily                          heating advantage
• When sloped 40 deg or         • Must use antifreeze solution
  more, sheds snow sooner         because of manifold design
• Less expensive                • Components are
• L
  Longer design track
           d i t k                assembled on site
  record for durability         • Glass requires extra
                                         g
                                  handling care

                                                          22
Wet, Sticky Snow, Overcast
         Conditions
         C diti




        Courtesy Solar Skies Mfg.

                                    23 23
Hours Later




       Courtesy Solar Skies Mfg.
                                   24 24
             Needs to Be Cleaned Off




Evacuated tubes days after snowfall




                                      25
bob.rohr@caleffi.com   26
                  g
        Orientating Solar Panels
Ideal orientation is true south
                    g      generally results in less
“Plus or minus 30 degrees” g       y
  than 5% energy penalty
Adjustment compass reading for “magnetic
 declination”




                                                       27
                    g    g
Solar Panels are Forgiving for Pitch
  Plus or minus 15 Degrees Results in Only 5% Penalty




                                                                    28
   Graph courtesy of Solar Skies Mfg. LLC, Minneapolis, Minnesota
Ground Mount Array
Ground Mount Array




                                              29
       Photo courtesy of Hot Water Products
                    y
   Ground Mount Array 




                                       30
Photo courtesy of Hot Water Products
           Collectors-
Flat Plate Collectors- Ground Mounted




                                             31
 Cedar Mountain Solar Santa Fe, New Mexico
Awning Mount 
Awning Mount




Photo courtesy of Hot Water Products   32
Flat Plate - Vertical Wall Mounted




         Cedar Mountain Solar
                                 33
High Tilt for Space Heating




                          34
Ground Mount With Air Conditioner




                                       35
Photo courtesy of Hot Water Products
Reverse Pitch Mounting




Beaver Brothers NC   36
Commercial SDHW
Commercial SDHW




                                        37
 Photo courtesy of Hot Water Products
            Freeze Protection Methods

                  y
All active solar systems in the US 
and Canada should employ freeze 
protection

“Manual draining” should be used 
only when freezing is extremely 
only when freezing is extremely
rare




                                        38
                              Drain back System
                              Drain back System




                                                  39
Radiant Engineering, Bozeman, MT
Gravity Drainback Systems

   i b l t l               th t th    ll t       d ll        d i i be it h d
It is absolutely necessary that the collectors and all exposed piping b pitched a
minimum of 1/4 inch per foot toward the storage tank for complete drainage.




                                                   Entire collector array is sloped
    “Closed‐Loop Drain back” Freeze Protection

Water from collect or drains 
automatically when collector 
automatically when collector
is not collecting energy
Relies on gravity and proper 
pitching of collectors and 
piping
Anti freeze is not needed 
Anti‐freeze is not needed
(however, some choose to 
anyway for extra protection)




                                             41
    “Closed Loop Glycol” Freeze Protection

Uses  anti‐freeze
A heat exchanger 
  transfers heat to 
     t i t          t k
  water in storage tank
The majority of 
  installers prefer over 
  installers prefer over
  “drain back” 
  protection



                                             42
Glycol     40/60 Mix




                       43
   Basic System Configurations
3 sizes:
    1 Panel‐ Target 1 to 2 person household
         Ave 15,000 BTU harvested/day
   2 Panels‐ Target 2 to 4 person household
         Ave 27,000 BTU harvested/day
   3 Panels‐ Target 4 to 6 person household
         Ave 40,000 BTU harvested/day
Sized to reduce energy costs 45% to 90%
(depending on North American region)


                                              44
           Software for System Sizing, 
    Performance…and Return on Investment!

•RET Screen www.retscreen.net

•F-Chart www.fchart.com

•Maui Solar www.mauisolarsoftware.com

•Tsol www.valentin.de


                                        45
                Configuration #1
                                        Back-
Storage Tank Electric Element Serves as Back-Up Heat
                        Source




                                     (Optional Accessory)




                                                            46
               Configuration #2
Storage Tank Feeds Dedicated Hot Water Heater




                                       (Optional Accessory)




                                                     47
          Configuration #3
                   Back-
Boiler Is Used For Back-Up Heat



                        (Optional
                        Accessory)




                                     48
Remember, Always Use Thermostatic
          Mi i Valve!
          Mixing V l !




                                    49
bob.rohr@caleffi.com   50
bob.rohr@caleffi.com   51
                   Boulder, CO
4 person household with hot water heater
  Ave Daily HW Consumption = 80 gallons
  Ave Incoming Cold Water Temp = 46.7 degrees
  HW Temp Delivery= 120.0 degrees
                                                      /
Daily energy delivery = 8.33x80x(120‐46.7) 48,847 BTU /day
Daily energy consumption (assuming 3% storage loss) yields 
50 312 BTU /day
50,312 BTU /day  
Two panel Caleffi System produces 32,200 BTU / day solar 
energy
Solar fraction = 32,200 / 48,847 = 64%


                             How much money does, this
                                  save customer?
                                                         52
                   Since 2002, Average Annual Inflation: 
                               Electricity 3%
                                         y
10% increase
projected for 2008/09
heating season!




                 Source   http://www.eia.doe.gov/steo Oct 2008 Update   53
  Since 2002, Average Annual Inflation: 
      Propane 15%, Heating Oil 22%
         p        ,      g




Source   http://www.eia.doe.gov/steo Oct 2008 Update   54
  Since 2002, Average Annual Inflation: 
            Natural Gas 11%




Source   http://www.eia.doe.gov/steo Oct 2008 Update   55
Incentive Effect Example
I     i Eff E         l
 -- 2 Panel Solar System
                g
 -- SRCC Rating 50,000 Btu




                             56
       Energy Savings Analysis
Average Daily Solar Harvest= 27,945 BTU/day
Annual Avoidance = 27,945 * 365= 10,199,125 BTU




                                                  57
Solar Fraction Varies By Region 




                                   58
                y       p     y
      The Fallacy of Simple Payback
          • It’s good for comparison (only!)
                g
          • It ignores inflation rate
          • It doesn’t look at lifetime
          • It ignores “afterwards”



                             Payback Time

Initial Cost




                                               Incremental
                                                 Savings
Solar Thermal Federal Income Tax Credits

     Credits Extended Through Year 2016


     Residential Installation
       30% of installed cost
       No cap on credit amount


     Commercial Installation
       30% of installed cost
       No cap on credit amount


                                          60
             More Incentives
             More Incentives
  Solar grants for low and moderate income 
• Solar grants for low and moderate income
  families
  Utilities rebates on PV, sales and use tax 
• Utilities rebates on PV sales and use tax
  incentives
  Climate Smart loan program
• Cli       S     l




                                                61
                         OG-
SRCC Label Certifying to OG-100
          Standard
          Standard




                              62
Flat Panels Are Very Durable




                           63
Locating Rafters Electronically




                                  64
Drill Stainless Steel Anchor 
      Bolts Into Rafter
      B lt I t R ft




                                65
Threaded  rod, cross block
Threaded rod, cross block




                             66
L bolt under rafter
L bolt under rafter




                      67
Close Ups Of Mounting Hardware




                                 68
Stainless Steel Hardware




                           69
Panel To Panel Union




                       70
Roof Pitch Gauge




                   71
Adjusting Panels to Proper Pitch




                                   72
      Ideal Solar Panel Pitch
      Ideal Solar Panel Pitch
• For Solar Water Heating
    Set
   –Set at local latitude (from horizontal)
   –Make the pitch at least 40 degrees in
    snowfall climates

  For Space Heating
• For Space Heating
   –Set at local latitude + 15 degrees




                                              73
Tilt Brace Assembled




                       74
75
76
77
Solar Flex In PVC Sleeve ‐ Attic View




                                        78
Splitting Solar Flex




                       79
                g             g
Solar Flex Through The Building




                                  80
Procedure: Setting System Pressure
• Set to accomplish 20psi at top of solar panels
• Procedure:
   – For every floor level between solar panel and
     storage tank top, add 5 psi
   – Example:
           Tank i i basement and panels are on
         • T k is in b         t d       l
           roof of one story home.
         • Set pressure to = 20 psi + 5 psi/floor * 2
           floors = 30 psi
           fl            i
• Adjust expansion tank pressure to equal the 
   y     p
  system pressure



   Spin off

                                                        81
           Flow Setter Reading




                          For flow
                          above 4
                          GPM, read
                          from bottom
                          of impeller
                          indicator
Shows 2.0 GPM




                                        82
                            g
           Procedure: Setting Flow Rate
• Desired Flow Rate Value:
   – For one panel system: 1.5 GPM
   – For two panel system: 2.0 GPM
   – For three panel system: 3.0 GPM
  Open balancing valve full open and set pump speed to 
• O      b l i          l f ll         d                d
  lowest setting
  Adjust controller to  manual on to activate pump
• Adjust controller to “manual on” to activate pump
• If flow rate is greater than desired value, use balancing 
  valve to adjust back to desired value
• If flow rate is less than desired value, set pump to 
  second (or third if needed) speed setting and adjust 
  back to desired value.
  back to desired value.

                                                               83
•
                                                 g g
                                   Procedure: Purging Air
    1) Open air vent ball valve on solar panel
    1) Open air vent ball valve on solar panel
     – You will likely hear air being expelled from air 
       vent
• 2) Manually open air vent located in pumping station
     – Air should  also expel. When fluid begins to 
       expel, close vent. 
• 3) Within the next few days after fluid heats:
       Repeat step 2) above after manually turning on 
     – R      t t 2) b          ft         ll t i
       pump. When only fluid expels when manual 
       vent is opened, system air has been sufficiently 
       removed. Check that pressure hasn’t changed. 
     – Close air vent ball valve on solar panel. The air 
       vent is no longer needed and can be removed if 
       desired for aesthetic purposes.
  5) Repeat step 2) approximately every 12 months and expel any 
• 5) Repeat step 2) approximately every 12 months and expel any
    trapped air. Check pressure gage to ensure pressure hasn’t dropped 
    below desired level. If so, re‐pressurize system to maintain optimal 
    performance.




                                                                            84
                       Pump Speed Control
                          Operating Sequence

• Pump automatically adjusts speed based on the heat gain in the panel. 
  The faster the heat gain, the faster the pump speed. 
   –Optimizes thermal transfer efficiency in the tank
                                p
   –Minimizes electrical consumption.
• Sequence (starting at night with a cooled tank)
        •   Sun starts to rise. Delta T reaches 12F.
        •                                           seconds,
            Pump activates to 100% speed for 10 seconds then drops to 40%
        •   If Delta T rises to 20F, speed increases to 50%
        •   If Delta T rises to 24 F, speed increases to 60%
        •   This process continues – pump speeds up and slows down based on
            Delta T.
• Once Delta T drops below 8F, pump turns off. 


                                                                        85
                     Built In Heat Protection
                            Operating Sequence
                            Operating Sequence
•   Heat transfers from panel to tank until tank temperature 
    reaches 140 F. Pump then becomes temporarily disabled even 
    though panel temperature may continue to climb
    though panel temperature may continue to climb
•   If panel temperature rises to 250 F, the pump activates, 
    cooling the panel. Tank temperature may rise above 140 F 
    t          il
    temporarily.
•   If either the panel temperature reaches 285 F, or the tank 
    temperature reaches 203 F, the system shuts down 
    (stagnates) and  the control flashes. Under prolonged 
    (t      t ) d th         t l fl h U d           l    d
    “stagnation” states, the antifreeze properties can degrade.
•   Pump will re‐energize when panel temperature cools below 
    285      t kt         t        l b l 203
    285, or tank temperature cools below 203.
•   Annual glycol ph checks are recommended to detect 
    stagnation occurrence. 

                                                           86
87
        Differential Temperature Controller is 
                      “The Brains”
Monitors two temperatures

When collector temp exceeds
 storage tank temperature by
 about 12 F, pump circulates

When temperature difference
 falls to about 8 F, controller
 turns pump off

Frequency of energizing
                   cover, wind,
 depends on cloud cover wind
 shading, energy consumption



                                             88
                     y        p
                Yearly Check‐Ups
• System pressure check, glycol property check, and air purge 
  should be performed every year to ensure adequate 
  p
  performance. 

• Record any glycol adjustments on glycol tag provided.




                                                                 89
Solar Interest is Not Exclusive to Just the 
                 Affluent!
bob.rohr@caleffi.com   91
bob.rohr@caleffi.com   92
Solar Thermal and PV




                       93
Solar Thermal and PV




                       94
Thanks for considering solar!!

								
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