Some more clarity on limited role of biomass in reducing the UK’s carbon emissions for the following reasons:- To meet the UK’s heating demand we would have to carpet the country with biomass crops and ship more in from countries like Malaysia, Canada etc.
- To meet 10% of the UK’s heating demand we would have to plant energy crops on 20% of arable land in the UK, equivalent to 1 million Ha[1]
- Biofuels and biomass are both competing for the same resource i.e., arable land, as well as that which is required for food cultivation. The European Council has sets a binding biofuels target of 10% for road transport fuel by 2020[2]. This, if grown in the UK, will require 3 million Ha or 60% of the UK’s arable land area. If one takes into account that there are ambitious plans to scale up the use of biomass for UK power generation (15% from biomass[3]), then the area of arable land required will be much greater than available.
- Usually waste wood (e.g., from saw mills) is quoted as a source for biomass feedstocks, however this is not a scalable alternative; the timber for the waste wood would need to be grown somewhere (probably in Canada or Northern Europe). Trees for timber grow more slowly than energy crops do, with a yield of <5t/Ha/yr and assuming 10% is waste wood, then a net supply of only <0.5t/Ha/yr. On the other hand, energy crops (e.g. coppiced willow) provides approximately 10t/Ha/yr. Therefore the same argument regarding availability of land area would apply and waste wood biomass becomes less viable on a larger scale.
- Importing biomass from temperate forests such as Canada or Northern Europe is not sustainable for two reasons i.e., impact of transporting the low energy density fuel and when viewed at a worldwide scale the supply from these sources is marginal (115% of the arable land will need to be cover in bio-crops to provide for the world energy demand).
- It goes without saying that importing biomass (or biofuels) from tropical areas, either forests or farmed must never be considered, as it will have disastrous impact on biodiversity and land available for people to grown food, especially from the poorer South.
Biomass has a limited role in UK’s fuel mix; because of its low energy density for the area of land available, it should only be used prudently for projects that have limited alternatives for example for displacing fuel-oil in existing sites.
[1]UK Biomass Strategy suggest increasing the amount of perennial energy crops produced in the UK to to around 1 million hectares, equivalent to 17% of total UK arable land http://www.globalbioenergy.org/uploads/media/0705_Defra_-_UK_Biomass_Strategy_01.pdf
[2] www.erec.org/renewableenergysources/biofuels.html
[3] The UK Government’s Department for Energy and Climate Change (DECC) has set a target for 15% of the UK’s renewable energy to be generated by biomass by 2020. www.coaltransinternational.com/htm/w20091113.696970.htm
