Biomass is ready to play its part in fighting climate change
Forty years is a long time, half a lifetime even. But over 40 per cent of the UK's current generation capacity was running, in construction or in advanced planning, 40 years ago, and almost no capacity of that vintage or younger has yet been decommissioned. Thus, as the power generation industry contemplates its role in the UK's legally binding commitment to reduce greenhouse gas emissions by 80 per cent by 2050, decisions taken now will play a massive role in deciding whether or not this important target will be met.
The realistic candidates for near-zero carbon generation on a national scale are wind, nuclear, coal fitted with carbon capture and storage (coalCCS), biomass and tidal. There is little doubt that some mix involving at least the first four of these technologies will be required to meet a power demand which may well rise significantly to accommodate new forms of electric transport.
What concerns me about official predictions of the future is that few seem to take account of the requirements for load matching. Generation must be dispatched on and off to meet variable demand and this creates a merit order of plant with different utilisation rates. Of the five technologies, three (nuclear, wind and tidal) are completely non-despatchable, by which I mean that, if anything, it costs more to turn them off or down than to keep them running, and these must run when available. CoalCCS is more flexible but still has high capex costs, so that the power it produces will be expensive unless it operates at a good load factor.
That probably leaves biomass alone to fill the role of lower-mid-merit generation, although demand-side flexibility and additional interconnection to Europe may also help with system balancing. The vast number of wind turbines planned for both the UK and the continent will only increase the need for flexible generation.
I believe that large-scale biomass generation can meet this challenge at an acceptable cost, but I am worried by the lack of early engagement from the major players - there is a development curve to go through, on the technology and fuel side. The big six UK energy utilities have deployed massive resources to develop plans for wind, nuclear and coalCCS, but so far their involvement in dedicated biomass has been small scale. The total amount of dedicated biomass constructed or being actively developed by the big six is about 300MW, not much bigger in thermal terms than the single biomass boiler at Alhomens Kraft in Finland, which has run with excellent reliability since 2001. It would be almost unthinkable to build a new import-based coal boiler at half the scale or less of the most efficient proven reference plant, yet that is the most that any of the big six plan to do for biomass.
The utilities cannot use economics as an excuse. Capex per MW for the biggest biomass boilers is far lower than for nuclear, wind or coalCCS. What is more, the cost of the biomass fuel is entirely offset by Renewables Obligation Certificates and Levy Exemption Certificate income (under the new Renewables Obligation banding legislation) for 15 years, although only for the most efficient plant sited at the best locations. With the right approach, sustainable biomass fuel can be procured on secure, long-term, fixed price contracts, in stark contrast to gas, the future price of which is anyone's guess. Today's power grid is long on flexible gas and coal plant and short on low-carbon generation, therefore it makes sense for biomass plants to run baseload for now and then switch to mid-merit running later when new nuclear and wind plant start to dominate the system.
People often complain that big plants will rely on imported biomass. I don't deny it, but there is no reason why, in the long term, the UK cannot produce its own biomass. There has never been a market attractive or stable or large enough to encourage efficient industrial scale fuel development. It is chicken and egg, but with farmers having had their fingers burnt in the past, demand will have to precede supply. Imported sources are able to bridge the gap, but UK-produced fuel, transported by rail, barge or coaster, could compete strongly on price, especially with energy crop status.
The UK could eventually produce enough sustainable biomass to fuel 10GW of mid-merit plant without affecting food supply. Such a target would require the Forestry Commission to start meeting its targets for new forest plantations, for a large but realistic proportion of previously set-aside or disused land to be converted to short rotation forestry or other perennial energy crop, and for much greater extraction of biomass from waste streams. All of those things would take time, but are achievable. The prize is a flexible, secure, sustainable and competitive source of energy and tens of thousands of new jobs.
Ben Elsworth, director MGT Power
http://www.mgtpower.com/
