Creating Value from Steam Pressure

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FREE ELECTRICITY Making the most of a CHP System
Design Presented to the World Energy Engineering
Congress Atlanta, GA November 12, 2003
Sean Casten Chief Executive Officer 161
Industrial Blvd. Turners Falls, MA
01376 www.turbosteam.com
Creating Value from Steam Pressure
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The economics of all power generators are based
on a few very simple calculations

• What is my fuel cost?
• What is my electricity value?
• How much spread do I need to cover OM, capital
  recovery profit?
• When one considers real-world, location-specific
  fuel and electric rates, it becomes apparent that
  even with a very modest 3 c/kWh spark spread, the
  market for power-only generation is nearly
  non-existent (see next)
• This forces DG designers to add ancillary value
  to their system designs.

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30 40 efficient generation isnt enough!
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So how do you make the economics of DG work?

• Only target states with attractive spark-spreads
• No surprise that most DG installers market
  heavily into CA, NY, MA, NJ
• Chase higher value power
• Premium power market is real, but limited
• Chase lower-cost fuel
• Wood-waste, coal, landfill gas all present more
  favorable economics but are much harder than
  gas to site or permit
• Chase efficiency
• CHP systems recover free heat to realize added
  value, bump efficiency up.

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However, while CHP is typically understood to
take a power-first approach to generate free
heat
Electricity
Free Heat
Power Generator
Heat Recovery Device
Fuel
Waste Heat
Without Heat Recovery
Cost of Power Generation
With Heat Recovery
Fuel Cost
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there are many opportunities to take an inverse,
heat-first approach to generate free
electricity.
Useful Heat
Free Electricity
Heat Generator
Power Recovery Device
Fuel
Waste Heat
Without Power Recovery
Cost of Heat Generation
With Power Recovery
Electric Cost
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Properly designing heat-first CHP is a
near-exact inversion of power-first approaches.

• 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.

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One flavor 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
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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)
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Turbosteam has installed 164 systems worldwide
following this approach.
Non-U.S.

• 17 countries
• 63 installations
• 35,900 kW

gt10,000 kW
5001 10000 kW
1001 5000 kW
501 1000 kW
1 500 kW
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A closer look at heat-first economics.
Cost of delivered thermal energy before power
recovery
Cost of delivered boiler fuel
All-In Cost of Generated Heat
Retail Electricity Rate
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.
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The opportunity for heat-first CHP is entirely a
function of a given facilitys 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

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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

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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
• gt60 Project ROA

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Implications
Power-first CHP
Heat-first CHP
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So what is heat-first CHP?
The only distributed generation technology that
is proven to be economically and environmentally
beneficial on every corner of the globe.