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Biomass most often refers to organic matter, such as timber and crops – grown specifically to be burnt to heat water or air. Biomass also refers to agricultural by-products such as straw, grain husks, forest products, waste wood and animal wastes such as slurry and chicken litter.

The most likely applications on a pig farm are heating water for creep mats, weaner room heaters, washing, staff room and office central heating.

Biomass is sustainable and generally carbon neutral because the carbon released in the combustion process is offset by the carbon trapped in the organic matter by photosynthesis during its growth.
To be truly carbon-neutral, the products must be sustainably sourced and re-planted after harvest or allowed to regenerate so carbon is reabsorbed in a continuous and virtuous cycle.

Biomass crops
The most popular biomass crops in the UK are short Rotation Coppice, Willow and Poplar, Miscanthus (Elephant Grass), Reed Canary Grass and Oil Seed Rape. These can be used after drying and shredding or processed further for efficient handling.

Given that delivery cost increases with distance and wood chip is a bulky product, its use is favoured within close proximity to the source of supply and with covered storage facilities capable of taking a farm trailer or 60m3 load from an HGV.

Some suppliers will blow the chips, others tip. In the absence of covered storage facilities, pellets supplied in bulk bags (1 tonne) may be considered.

Alternatively, biomass can be pressurised to produce syngas – a process called gasification. This gas can be used for directly heating water or to fuel engine driven generators to produce electricity and heat (from the engine), a process called combined heat and power (CHP).

Feed in Tariffs
Government approved MicroCHP units (≤2kW) qualify for ‘Feed-in Tariffs’ (FITs) which is a payment for total electricity produced (Generation Tariff) plus a supplement for electricity fed back into the grid (Export Tariff). In addition, money will be saved by not buying-in electricity.