Optimising Woodfuel Project ReturnsThrough Heat and Power Generation
CLA Woodfuel ConferenceDr Andrew Horsley, 30th October2013, Doddington Hall
About Arbor Heat and Power
• Innovative but pragmatic renewable energy solutions tailored for built environment
• Upfront consultancy services through to implementation and maintenance
• Investment in research and development to identify technologies for future applications
Introduction
• Woodfuel energy projects traditionally focussed around heat only
• Heat and Power (CHP) can be cost effectively generated from woodfuel using gasification technology
• Project planning and design requires different considerations
• Financial returns and carbon savings can be greatly enhanced over “heat only” projects
Biomass CHP - ConceptThermal
Store
CHP System
Backup Boilers
National Grid
House, Wood Fuel
Drying or Leisure
Renewable Heat
Supply
Import/Export
Electricity to balance
demand/supply
Renewable Electricity
Supply
Heat Supply for space
heating and hot water
Renewable
Fuel Supply
Natural Gas/Oil/Biomass
Biomass
Gasification
Syngas
Waste Heat
to Dry
Woodchip
What is Advanced Gasification?
Modelling Heat and Power Use
Modelling Heat and Power Use
-1500.00
-1000.00
-500.00
0.00
500.00
1000.00
1500.00
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Plant Operation over Selected 7 Days
Demand kWth
Boilers kWth
Thermal Store kWth
CHP kWth
-600.00
-500.00
-400.00
-300.00
-200.00
-100.00
0.00
100.00
200.00
300.00
400.00
1 25 49 73 97 121 145
Plant Operation over Selected 7 Days
Demand kWth
Boilers kWth
Thermal Store kWth
CHP kWth
Biomass CHP Package 30kWe
• Scalable Solution down to 30kWe
• Other sizes 200kWe, 400kWe and 800kWe
• Many potential applications
Biomass CHP Package 30kWe
Woodfuel Requirements
• Coarse screw cut or screened wood chips
• Even quality with few fines
• Readily stored and dried
• Moisture content around 15-18%
• Wood drying opportunities are attractive projects in their own right
Woodfuel Requirements
Wood Drying Concepts
Financial Returns
• Offsetting traditional fuels: electricity and oil/gas
• Renewables Obligation Certificates – 2 per MWh electricity
• Renewable Heat Incentive 7.3p/kWh flat rate
• Exporting surplus electricity back to the grid
Typical Project Economics
Thermal Output
Electrical Output
Heat Offset Value
Electricity Offset Value
RHI Value
ROC Value
Annual Costs (fuel/maint.)
Annual Net Benefit
Capital Cost
Payback Period
Carbon Saving
Arbor ElectroGen (30kWe)
565,530 kWh
230,252 kWh
£47,238
£29,933
£40,153
£19,341
£46,000
£90,655
£407,947
4.5 years
295 tonnes
Summary
• Woodfuel can be converted to heat and power at small scale with highly attractive economics
• Project considerations are slightly different than for wood heat projects – smaller capacities with longer operating hours
• Careful integration and design is paramount• Wood fuel drying opportunities can offer heat loads to
optimise operation of plant throughout year• A viable alternative to biomass boilers in the right
circumstances• Carbon saving potential makes integration in rural new
build developments with strong planning objectives ideal
The Future – Next Generation Systems
• Small scale waste to energy CHP plants
– Removing waste disposal costs
– Providing clean low carbon energy
• First pilot plants in planning stages
