Heat-First CHP

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					 “HEAT-FIRST CHP”: FINDING THE FREE
ELECTRIC POWER IN YOUR STEAM PLANT
   Presented to AEE 2003 Annual Expo and Conference
    The Business of Energy Management in California
                     San Dimas, CA
                     March 20, 2003
                         Sean Casten
                     Chief Executive Officer
                       161 Industrial Blvd.
                    Turners Falls, MA 01376
                     www.turbosteam.com




                   Creating Value from Steam Pressure
The relationship between heat and power production: 4
observations
1. It is physically impossible to make electricity without also
   making heat – failure to recover this heat only serves only to
   increase the cost of power production.

2. 92% of the power made in the U.S. is made without recovering
   this heat.

3. The power industry is thus the only industry in which consumers
   can make a product more cleanly, cheaply and efficiently than
   industry professionals.

4. Every CHP installation reduces the need for less-efficient, dirtier
   generation on the grid, leading to a net reduction in fuel
   combustion and a net reduction in energy costs, as well as
   increasing local power reliability.
The proof: Steady centralization of power generation is directly
responsible for its steadily eroding efficiency.


100%
                                                                                            The Costs of Failure
90%           Power Industry                                          CHP Plan
                                                                              ts                (U.S. only)
80%                                                                                        • ~$100 billion too
70%
                 Efficiency                                                                  much money spent
                                                                                             on energy each year
60%                                                                                        • Over 1 billion too
                                                                                             many tons of CO2
50%
                                                                                             emitted from low-
40%                  Recovered                                                               efficiency power
30%                    Heat                                                                  generation each year.

20%

10%
                                    U.S. Average Electric Only
 0%
       1880   1890   1900   1910   1920   1930   1940   1950   1960   1970   1980   1990
The first choice a prospective CHP user must consider is
which “flavor” of CHP is most appropriate.


•   “Power-first” design: prime mover + heat recovery
     Recovered thermal energy displaces boiler fuel, reducing the
      delivered cost of electricity.
     Focus is electricity with steam as a byproduct
     Usually designed to maximize power output, then recover as much
      heat as is economically feasible.

•   “Heat first” designs: steam boiler + power recovery
     Recovered electricity displaces purchased electricity, reducing the
      cost of steam.
     Focus is on thermal with electricity as a byproduct
     Usually designed to maximize thermal output, then recover as
      much electricity as is economically feasible.
Technical summary of “heat first CHP”: typical steam plant
design

                                        High pressure steam process load




                                                         Medium pressure steam process load
                Boiler                Header
                         H.P. steam

   Feed water
        Fuel                               Pressure
                                           Reducing
                                          Valve (PRV)    Low pressure steam process load




                                               PRV
Our turbine-generators deliver the same pressure drop as a
PRV – but produce useful electricity in the process.




                                                  Low Pressure steam out




  High Pressure steam in




                                                  Electricity




 Note that this generator is sized to the thermal rather than
 electric load (thus “heat-first”)
 We have installed 95 systems in the U.S., and 155 worldwide.




                         “Typical” Project                 Non-U.S.

                  • 3,000 – 200,000 lbs steam/hr    • 17 countries
>10,000 kW                                          • 60 installations
5001 – 10000 kW   • 50 kW – 10 MW power output      • 36,000 kW
1001 – 5000 kW    • >30% IRR
501 – 1000 kW     • Application wherever steam is
1 – 500 kW          used
By reducing steam costs, Turbosteam solutions create
financial benefits and plant design flexibility.
     “All-In Cost of Generated Heat”




                                       Cost of delivered thermal energy before power recovery

                                       Cost of delivered boiler fuel




                                                                                          Cost of delivered
                                                                                          thermal energy
                                                                                          after power
                                                                                          recovery


                                                    Retail Electricity Rate
                                                                                                Note 1: At all electricity rates, the cost of
                                                                                                steam is reduced

                                                                                                   Note 2: In many cases, the cost of steam
                                                                                                   is reduced to less than the cost of fuel for
                                                                                                   steam generation!
Where note 2 applies, plants develop substantial downstream flexibility, since
steam-driven equipment – e.g., dryers, chillers, etc. – becomes more cost-effective
than direct-fueled alternatives.
How to calculate the cost of power generation from
backpressure turbine-generators.
                                                       Thermodynamics

                                          1st Law Balance                 Efficiency


   H.P. steam         L.P. steam                                       PRV Eff. ~100%
                                      H.P. energy = L.P. energy
                PRV                                                  Power Gen Eff. = 0%




  H.P. steam
                       kWh                                              PRV Eff. ~ 94%
                                   H.P. energy = L.P. energy + kWh   Power Gen Eff ~ Boiler
                  L.P. steam                                             Eff (80-85%)
             TG Set
         “Spinning PRV”


Compare: this is nearly 3X the efficiency of the U.S. power grid.
In actual operation, BP electricity looks free… or better (data
from Middlebury College)
                                    35% kWh increase
                                    14% fuel purchase increase
               3,500,000                                                        2,000,000
                               Boiler fuel purchase                             1,800,000
               3,000,000
                               Power generation                                 1,600,000




                                                                                            Power Generation
               2,500,000                                                        1,400,000
  Fuel purchase
  (gallons/year)




                                 TG Set #2 Installed




                                                                                               (kWh/year)
               2,000,000                                                        1,200,000
                                                                                1,000,000
               1,500,000                                                        800,000
               1,000,000                               TG Set #3 Installed      600,000
                                                                                400,000
                   500,000                                108% kWh increase
                                                                                 200,000
                                                          6% fuel purchase increase
                        0                                                       0
                        1981     1986          1991           1996           2001
                                               Year
The opportunity for heat-first CHP is entirely a function of a
given facility’s thermal load.

•   Recover electric power from existing pressure reduction
    stations
     Sized to downstream thermal load
     Maximize value by increasing thermal loads or pressure drop
•   Create pressure reduction opportunities in existing steam
    networks
     Increase boiler pressures – design and/or operating
     Reduce steam utilization pressure (often possible due to existing
      safety factors)
•   Convert mismatches in thermal generation and
    consumption into electricity
     Condense steam generated in waste-disposal boilers (sawdust
      boilers, thermal oxidizers, etc.)
     Recover steam energy from existing vents
    Sample installation: Morning Star Packing Company
    (California)




•    Tomato processor – produces 40% of tomato paste used in U.S.
     during 3 month operating season
•    Startup: 1995 (2 systems), 1999 (3rd system)
•    High pressure boilers produce steam for tomato cookers
•    PRV replacement + boiler pressure increase
•    Turbosteam systems generate 3,000 kW, reduces steam costs by
     $2.50/Mlb, reduces CO2 emissions by 2,700 tons/year.
•    Plant completely insulated from CA power crisis in 2000
•    >60% Project ROA
    Sample installation: Brattleboro Kiln Dry (Vermont)

•   Largest custom-lumber dryer in New England
•   Startup: 1989
•   Sawdust-fired boiler converts millwaste into
    steam which is used to heat on-site lumber
    kilns
•   PRV replacement
•   Turbosteam system generates 380 kW,
    reduces steam costs by $1.75/Mlb, reduces
    CO2 emissions by 570 tons/year
•   35% Project ROA
We have also been able to find opportunities throughout the
industrial, commercial and institutional market.
Turbosteam’s installations:
• Chemical/Pharmaceuticals    22
• Food processing             21
• District Energy             20
• Lumber & Wood Products      18
• Petroleum/Gas Processing    17
• Colleges & Universities     12
• Commercial Buildings        8
• Pulp & Paper Mills          6
• Hospitals                   6
• Military Bases              5
• Waste-to-Energy             3
• Textiles                    1                   KEY
• Prisons                     1                   Industrial
                                                  Commercial
• Auto manufacturing          1                   Institutional
So is there an opportunity in your facility?

                              Typical Values           Extreme Values

                                                    Above-market returns
Target Financial Return   <2 years simple payback          and/or
                                                    Non-financial drivers

 Inlet Steam Pressure            >150 psig                 15 psig

 Pressure drop across
                                 >100 psig                 15 psig
   turbine-generator

      Steam flow               >10,000 lbs/hr            2,500 lbs/hr

  Annual steam load
                              >6 months/year            3 months/year
       factor

 Local electricity rate          >4 c/kWh                >1.7 c/kWh

				
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