Biomass for heat production vs biomass for electricity production – what’s the difference? It is time to clear up the confusion between the two.
Heat and power are given the same ‘broad-brush’ approach by government. But the fact is, they are not the same.
This uncertain messaging has been going on for years.
There is long-running confusion about whether biomass is good or bad for the environment and whether biomass is best-used to produce heat or power.
Biomass heat and biomass power are two completely different creatures and, for policy drivers, must be treated differently.
The key question should be: is your biomass properly sustainable and how efficiently are you using it?
Drax – formerly Europe’s largest coal-fueled power station and now the UK’s largest biomass fueled power station – burns 18,000 tonnes of wood pellets imported from the US, every day. How can this be sustainable?
The fact that Drax uses wood pellets is beside the point because ALL electricity production from large thermal power generating stations is around 30% efficient – whether it is produced from oil, gas or indeed biomass.
This means that out of each unit of energy going into the power station, only about 30% gets converted into useable electricity. The other 70% goes up the chimney as hot air or is lost in transmission. It’s just one of the laws of physics.
Power production using biomass in centralised power stations is a sinful waste of a valuable resource. The best way to use this valuable resource is to generate heat.
Small-scale, localised biomass boilers producing heat are about 85% efficient.
Smaller companies in the biomass heat sector are tarred with the same brush as big power firms.
Biomass Heat vs Biomass Power
The UK is first for sustainability
There are numerous sources of biomass available but timber is the largest – and in the UK, the sector is very tightly regulated. Any felling activity requires a licence and all trees have to be re-planted within 12-24 months.
Biomass production in the UK is sustainable and bio-diverse. It has short, secure supply chains coupled with a highly-efficient production processes to make solid, energy-dense, biomass fuels.
Managed forestry involves thinning out trees. All good timber is sold to sawmills and timber merchants. The left-over cuttings – or forest floor ‘brash’ – is turned into energy by UK biomass producers.
Using locally-grown, locally-harvested wood and generating heat and power from brash left on the forest floor, is the most efficient and economic use of a sustainable local resource.
Backing this, Greenpeace reports say: ‘small, localised, heat-generating biomass with short supply-chains is good – it is really beneficial for forestry, biodiversity and jobs.’
True, economically home-grown wood pellets are best for the UK market
Combined heat and power boilers catch hot air that escapes and this can be used to create electricity – this hot air is also used to dry wood.
A process called ‘heat recovery’ takes new hot air from the hot air already captured and uses it again as a valuable resource.
Power that is home-grown, and the re-use of heat that escapes in electricity generation is the most efficient source of energy supply.
The UK needs home-grown biomass energy if it is to reach its target of net zero carbon emissions by 2050.