Renewables immune

David Knott
London
[email protected]

In previous periods of sustained low oil prices, the drift to power generation using alternate fuels has been slowed by the cheapness of oil.

In Europe this time around, however, with oil prices at their lowest in at least 12 years and expected to remain low, oil field developments are being stalled-yet there is no apparent slowdown in the rise of renewables.

Alan Weekes, environmental engineer at Arbre Ltd., Leeds, puts the reasons for this in the U.K. quite bluntly: "If you hold an NFFO contract, you are insulated from changing prices."

The U.K. Non-Fossil Fuel Obligation (NFFO) policy requires electricity suppliers to buy a certain amount of power from renewable energy sources (OGJ, Aug. 31, 1998, p. 27).

Arbre is building the first biomass integrated-gasification combined-cycle power plant in Europe, at Eggborough, U.K. The £28 million ($46 million) plant is due to be in operation by yearend.

Arbre, which is 85% owned by local water utility Yorkshire Water plc, is installing a 10 MW capacity plant, of which 8 MW is contracted to regional electricity utility Yorkshire Electricity plc.

Wood power

Not only is Arbre protected under the U.K.'s NFFO scheme, but also the European Union (EU) provided £10 million ($16.5 million) for development.

The Arbre plant is the first application of a wood-chip burning process developed by Sweden's TPS Termiska Processer AB, which it claims is more efficient than the steam cycle used in conventional coal-fired plants.

First, the wood chips are gasified, yielding a mixture in which carbon monoxide, hydrogen, and methane are the main combustible components. This "syngas" is then burned in a combined-cycle turbine.

Weekes said that the plant will initially be fueled with forestry residue wood chips. Arbre is plant- ing 2,000 hectares (8 sq miles) of willow, which will be coppiced to provide the bulk of the plant's fuel.

Shell's purchase

Meanwhile, the Shell International Renewables (SIR) unit of Royal Dutch/Shell bought a wood-burning district heating plant in Kirkenaer, 140 km northeast of Oslo, from the HEAS power company.

SIR was established by Shell to develop solar and biomass energy projects (OGJ, Nov. 24, 1997, p. 29). It plans to spend $4 million to upgrade the boiler plant, which supplies nine industrial and municipal customers.

The plant burns bark residues from an adjacent wood-processing facility. SIR plans to integrate the boiler with a new unit making fuel briquettes from wood waste. These will be marketed as an alternative to fuel oil for boilers.

Already a wind power fan, U.K. Energy Minister John Battle also supports wood-burning: "The energy- crops industry may be at an embryonic stage, but if we are serious about renewables providing 10% of our electricity needs by 2010, we must look to energy crops to make a significant contribution."

Weekes cited another bonus point for wood-fired schemes: "Energy crops are the way to go, and they fit in with European agricultural policy. Farmers could grow willow in set-aside land (left fallow in return for a European Union subsidy) without losing their set-aside subsidies."