Drax on road to conversion

Drax plc aims to convert one of the six coal-fired units at its 4,000MW Yorkshire power station to burn only biomass, but needs government policy change for the project to go ahead.

Electricity generation from biomass has not increased in recent years due to certain limitations in the policy framework, according to Drax CEO Dorothy Thompson: “Electricity generation from biomass has the potential to grow significantly and make a vital contribution to meeting the UK’s challenging renewables and climate change targets at least cost to UK consumers. This will only happen with the right policy framework.”

Following its recent commissioning of a co-firing facility, Drax has a co-firing capacity of 500MW at the site - though it is currently generating only 40-60% of this due to regulatory constraints.

Co-firing non-energy crop biomass receives just a quarter of the support under the UK’s Renewables Obligation that is available to offshore wind. There are also caps on the amount of regular biomass that can be supported in any one year.

The much less costly conversion option would complement rather than replace existing plans to develop three 290MW dedicated biomass plants in a £2-billion partnership with Siemens Project Ventures, Drax officials insisted.

The technical feasibility of a full conversion has only emerged over the last two years, noted David Love, newly appointed as director of regulation, communication and strategy at Drax.

“[Because of] the way it burns, forms an ash and the corrosive nature of the residual’s alkali metal, the technical guys said forget about it,” commented the Drax executive.

However, after the work with Siemens had been completed on the design of the dedicated plant, Love explained, it asked what the bolt-on costs of doing that to an existing station would be. ” This has caused us to look at it again.”

Love cautioned, however, that the conversion was “not slam dunk”, as there were some serious technical challenges, particularly as it had never been done on such a scale.

The decision between dedicated, versus co-firing versus conversion will depend on the support that the Government decides is appropriate for each of those different technologies, said Love.

Drax’s biomass push comes as the UK faces up to the prospect of power shortages over the next decade, with many power stations set to close due to new EU regulation on emissions.

Coal-fired power producers are struggling to get investment support to meet their NOx requirements, particularly given the current differences between coal costs and carbon and offtake costs.

Asked if Drax would eventually convert all six units to biomass, Love said: “That’s a long way down the road. Let’s get one unit converted, see if it works, and, if it does, look at the next. If the conversion works, if the business case stands up and you can source the biomass, then why not convert another one. Similarly with the dedicated plant, if that works, look at all our options and [decide whether to] build another one.”