Biomass CHP: Gasification

Learn about gasification in the context of Biomass CHP, the typical outputs and costs and the pros and cons of gasification.  

Back to: Biomass combined heat and power (CHP)

What is gasification?

In the context of biomass CHP, gasification is the process which converts biomass into a flammable gas, suitable to power an internal combustion engine. The engine is used to drive a generator for the production of electrical power. Gasification systems are typically relatively small-scale, with a ratio of heat to electrical output usually in the region of 2:1.

It is extremely important that combustion of the biomass fuel produces clean gas for the engine, so this type of biomass CHP will normally require a clean fuel source, such as wood pellets.

Typical outputs and costs

Electrical output

Heat output

Indicative cost

Tonnes of fuel per day*


50 kW

100 kW



Wood pellet

100 kW

200 kW



Wood pellet

1 MW

1.4 MW



Wood chip

2 MW

2.8 MW



Wood chip

*24 hour operation

Pros and cons of gasification


  • Highly incentivised through government subsidies
  • Reasonably scalable for smaller applications
  • Small footprint
  • High electrical–heat ratio
  • Can provide high-temperature usable heat up to 250°C
  • Large-scale gasification units can be configured to run on recycled timber


  • New technology with few reference sites
  • Small gasification units can only run on the best-quality, and therefore more expensive, wood fuels
  • High maintenance costs

Useful links

Go to Biomass CHP: Steam turbine

Go to Biomass CHP: ORC turbine (Organic Rankine Cycle)

Go to Biomass CHP: What about CO2?

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Nathalie Key

Research and Knowledge Exchange Manager

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