1. Ingwald Obernberger Peter Thonhofer
Project “GREEN BARBADOS” Electricity from Biomass – A competitive alternative for base load electricity production in large-scale applications and an interesting opportunity for small-scale CHP systems
Ingwald Obernberger
Peter Thonhofer

2. Overview BIOS – a short introduction
Biomass – a renewable energy source
Biomass to power – large-scale applications
Examples of large-scale power plants
Biomass combined heat and power – small-scale applications
Example for a small-scale CHP plant
The role of biomass to power within the “GREEN BARBADOS” project
Summary and conclusions

3. BIOS – a short introduction

4. BIOS - Company information
BIOS BIOENERGIESYSTEME GmbH, founded in 1995, is an internationally active R&D and engineering company with the main focus on bioenergy applications such as
District heating
Process heating and cooling
CHP (combined heat and power) applications
CHCP (combined heat, cooling and power) applications
Pelletizing plants
Hybrid (biomass/solar) plants

5. BIOS – selected references
40 biomass CHP and CHCP plants – based on ORC, steam turbine, screw-type engine, Stirling engine, vegetable oil and biogas including hybrid plants
9 plants for waste heat utilisation
13 biomass district heating plants
3 pellet production plants
3 cooling plants (absorption chillers and heat pumps)
more than 25 CFD simulation projects (development, design & optimisation of biomass combustion and gasification systems)
Lienz / A – CHP plant & district heating
Marstal / DK – CHP plant & solar heating
Fussach / A – CHCP plant

6. Biomass – a renewable energy source

7. Biomass – a renewable energy source
Biomass is a renewable energy source as long as it is used sustainably (the harvested amount must not exceed the growth)
Advantages of using biomass:
Biomass is chemically stored solar energy  thus, in contrast to wind or solar power it can be used on demand
Biomass is the renewable energy source with the highest short- and medium-term application potential
Prices of biomass are considerably more stable and lower than of fossil fuels

8. Energetic biomass utilization - carbon and mineral cycle
CO2 uptake via
photosynthesis
CO2 emissions
Biomass for
energy generation
(bound CO2 and minerals)
Combustion residue
biomass ash
Recycling of ash back to
forest or short rotation coppice
plantations
Uptake of nutrients
contained in the ash

9. Biomass utilization – example Austria
Total in 2011: 1,427 PJ; share of renewables: 28.2% Target for 2020: 34% of renewables
Source: Austrian Biomass Association, 2013: Basic data Bioenergy Austria

10. Renewable energies and bioenergy in Austria
Contribution of renewable energy sources to the gross energy consumption in 2011 [PJ]
Contribution of different sections on the total bioenergy utilisation in 2011 [PJ]
Source: Austrian Biomass Association, 2013: Basic data Bioenergy Austria

11. Percentage of the primary EU27 energy consumption covered by renewable energy sources
EU27 – 2020 targets:
20% renewable energy in gross final energy consumption
cutting greenhouse gases by 20%
reducing energy consumption by 20% through increased energy efficiency

12. Worldwide energy consumption
Overall (2011) Electricity production (2013)
Source: World Biomass Association

13. Fuels used in biomass combustion plants
Woody biomass fuels
Bark
Industrial wood chips
Sawdust
Forest wood chips
Short rotation coppice
Waste wood
Pellets, briquettes
Herbaceous biomass fuels
Straw, cereals
Grasses (miscanthus, giant reed)
Alternative biomass fuels
Kernels, shells, rice husks etc.

14. Fuel selection and appropriate conversion technology
The selection of biomass fuel sources is important since the fuel quality differs from species to species
As a consequence, the biomass conversion technology needs to be adapted to the fuels available

15. Biomass to power – large-scale applications

16. Technologies for industrial biomass combustion
up to 50 MWth > 20 MWth > 30 MWth all sizes

17. Large-scale biomass to power applications
Biomass to power applications – characteristics & combustion technologies (I)
Large-scale biomass to power applications
> 20 MWe power output
Power generation only (excess heat is cooled off)
Net electric efficiency: > 30%
Combustion technologies:
Bubbling fluidised bed combustion (BFBC)
Circulating fluidised bed combustion (CFBC)
Pulverized fuel combustion
Power generation technology
Steam turbine
BFBC CFBC

18. Examples of large-scale power plants

19. Large-scale power plants (I)
Wilton 10 power plant:
Location: Middlesborough, England
Start of operation: 2007
Power output: 35 MWe; net electric efficiency (based on NCV): 30%
Combined heat and power production (currently power only)
Technology: Bubbling fluidized bed combustion, steam boiler, (520°C/120 bar) steam turbine
Fuel demand: 300,000 t (wet basis) such as forest residues, wood processing residues, waste wood, short rotation coppice
Fuel logistics: fuel supply by truck & rail, storage capacities for 14 days, fuels are either delivered ready to use or are processed on site
Investment costs: £64 million

20. Large-scale power plants (II)
Wilton 10 power plant: process diagram

21. Large-scale power plants (III)
Steven's Croft biomass power station:
Location: Lockerbie, Scotland
Start of operation: 2007
Power only
Power output: 44 MWe, net electric efficiency (based on NCV): 29%
Technology: Bubbling fluidized bed combustion, steam boiler (537°C/137 bar), steam turbine
Fuel demand: 480,000 t (wet basis)
Fuels used: forest wood and agricultural residues, urban wastes and short rotation coppice
Fuel logistics: fuel supply by truck, storage capacities for 14 days, fuels are either delivered ready to use or are processed on site
Investment costs: £90 million

22. Large-scale power plants (IV)
Aerial view Steven's Croft biomass power station:
Main round wood storage area
Boiler house
Fuel storage (10,000 m³)
Chipped wood storage area
Condenser
Fuel processing

23. Large-scale power plants (V)
Polaniec, Poland
205 MWe, circulating fluidized bed combustion, steam boiler (565°C/127 bar), steam turbine
Power only, net electric efficiency (based on NCV): 36.5%
Fuel demand 1,110,000 t/a (wood chips and agricultural residues)
Fuel logistics: fuel supply by ship, truck & rail, fuels are stored and processed on site
Simmering, Austria
17 MWe (CHP mode), bubbling fluidized bed combustion, steam boiler (520°C/118 bar), steam turbine
Combined heat and power production, net electric efficiency: 27%, thermal efficiency: 59%, total efficiency: 86%
Fuel demand 130,000 t/a (wood chips); fuel supply by ship, fuels are stored and processed on site

24. Biomass CHP – small-scale applications

25. Small-scale biomass CHP applications
Biomass CHP applications – characteristics & combustion technologies (I)
Small-scale biomass CHP applications
kWe power output
Combined heat and power generation only (in combination with process or district heating)
Net electric efficiency: 5 – 15%
Thermal efficiency: 70 – 80%
Overall efficiency: up to 90%
Combustion technology:
Fixed bed (grate) combustion
Power generation technology
Organic Rankine Cycle (CraftEngine)
CraftEngine

26. Biomass CHP applications – characteristics & combustion technologies (II)
Plant layout grate furnace with pressurized hot water boiler and CraftEngine

27. Correct dimensioning of a biomass CHP plant
A minimum of 5,000 full load operating hours is a target for an economic operation of CHP plants  a correct dimensioning based on local constraints is important!
Thermal output of the
CHP plant in %
Nominal thermal power
BM - CHP

28. The role of biomass to power within the “GREEN BARBADOS” project

29. Basic principles for green energy production
Use an efficient mix of renewables
Biomass
Solar
Wind
Geothermal energy
Waste
Utilize the optimisation potential regarding energy savings and efficiency improvements
Efficient energy generation
Efficient energy distribution
Efficient energy utilization

30. Potential fuel sources for “GREEN BARBADOS”
Pellets
Transport per ship from North America
Industrial wood chips
Local sawmills (if available)
Transport per ship from North and South America
Short rotation coppice
From local agricultural land (e.g. former sugar cane plantations)
Yield dependent on local conditions (typical yields vary between 10 and 30 t/ha*a (dry basis))

31. Biomass to power within “GREEN BARBADOS” (I)
Biomass to power - large-scale application:
Centralized power generation
providing base load power by replacing conventional fossil fuels (e.g. diesel)
Continuous operation at full load to minimize power generating costs
Biomass fuel supply by ship transport
Biomass fuel supply may also serve decentralized small- scale CHP applications
Combination of biomass and solar power possible

32. Biomass to power within “GREEN BARBADOS” (II)
Scenario for a large-scale biomass power plant:
Average power demand Barbados: 120 MWe
Peak power demand Barbados: 157 MWe
Base load coverage by biomass power plant: 50 MWe
Technology: fluidized bed combustion with steam boiler and steam turbine
Target net electric efficiency: 35%
Full load operating hours per year: 8,000 h
Annual electricity production: 400 GWh (about 40 to 45% of the annual demand)
Fuels used: pellets, industrial wood chips, short rotation coppice
Fuel demand: from 250,000 t/a (wet basis, pellets) to 500,000 t/a (wet basis, industrial wood chips)

33. Biomass to power within “GREEN BARBADOS” (III)
Biomass CHP - small-scale application:
Decentralized units with combined heat/cold and power generation
Operation at sites with rather permanent power and heat/cold demand providing power and reducing the electricity demand for chilling/cooling
The size of the small-scale applications is dependent on the local heating (e.g. for drying processes) or chilling/cooling (process cooling, space cooling) demand
Heat controlled operation: Heat is the main product and power a valuable by-product
Buffer tanks for an intermediate heat storage can be meaningful to avoid load fluctuations

34. Biomass to power within “GREEN BARBADOS” (IV)
Scenario for a small-scale biomass CHP plant:
Power output: 30 kWe, Heat output: 400 kWth
Technology: fixed bed combustion (grate furnace) with pressurized hot water boiler and CraftEngine
Target net electric efficiency: 6 - 8% (based on fuel input NCV), thermal efficiency: %, overall plant efficiency: 88%
Full load operating hours per year: 5,000 h
Annual electricity production: 150 MWhe
Annual heat production: 2,000 MWhth (flow temperature 81°C, return temperature 70°C)  potential use for drying or cooling/chilling processes
Fuels used: pellets, industrial wood chips, short rotation coppice
Fuel demand: from 530 t/a (pellets) to 1,000 t/a (industrial wood chips)

35. Summary and conclusions
Biomass is an important renewable energy source with the highest short- and medium-term application potential world-wide
Biomass to power and biomass CHP applications represent state-of-the-art renewable energy solutions
Potential fuel sources for “GREEN BARBADOS” are pellets, industrial wood chips and short rotation coppice
Two potential application options have been identified:
Large-scale power plant for national base load power coverage
Decentralized small-scale CHP plants for power and heat generation for locations with power and heat/cooling/chilling demand

36. Thank you very much for your attention!
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