Web exclusive posted March 11, 2008 at 1:57 p.m. CST

The world's largest wood-burning power station, capable of generating 350 megawatts of electricity, is nearing construction. Typical wood burners generate five or 10 megawatts, and until now, a 40-megawatt plant had been considered big.

The facility is in Port Talbot on the western side of Wales on a deep-water port that is crucial to the project's economic viability. The vast quantities of woodchips needed to fuel the power station - approximately 3 million tons annually - will be imported by cargo ship, the cheapest way to bulk transport.

Prenergy Power Ltd., a subsidiary of privately held Switzerland-based Global Wood Holding SA, developed the €400 million ($788 million) project with Italian and Taiwanese ownership and interests in both shipping and biomass.

No firm date has been announced as the start of construction other than some time this spring, said John Anderson, Prenergy spokesman. The plant is due to start operating in 2010, when it will provide sufficient electricity for some 587,000 homes and meet 70 percent of Wales' renewable energy target.

The woodchips will be imported from "a number of countries in North and South America and Europe," according to Anderson. "All the sources will be independently certified as sustainable," he told Biomass Magazine.

The company is still investigating how best to dispose of the estimated 80,000 tons of ash that the plant will produce annually. The ash can be used as fertilizer, cement additive or go to a landfill. "Our preference is strongly the first option, and we are working with forestry experts to develop methods of conditioning the ash to produce the right characteristics to allow it to be easily spread," said Anderson.

Peter Richards, business manager of Austrian biomass energy company Cycleenergy, said that the Port Talbot project is intriguing because of the sheer size of it. "It is something like sending a man to the moon because of its phenomenal size," he said. "The logistics of getting enough fuel to the plant will be very interesting."

For some experts, the fact that the power station will generate only electricity and not heat locally throws doubt on the project's green credentials. "My big concern with generating electricity from wood is that if you are simply lighting a big fire under a big boiler to solely produce electricity, you are losing 60 [percent] to 70 percent of useful energy through heat loss," said Dan van der Horst, a biomass researcher at the University of Birmingham in England. "In this regard, a brand new biomass plant producing only electricity is a bad idea."

One way of tackling this issue is to feed the excess heat to local homes and businesses in a combined-heat-and-power system. However, some industry insiders say that while combined heat and power is undoubtedly the more desirable option, the infrastructure doesn't exist in the United Kingdom to make such an approach viable on a large scale.

Concerns have also been raised about the pollution caused by transporting the woodchips by sea, although Prenergy insists it's the greenest option for carrying such a large amount of cargo.

More information about this facility and the logistics of long-distance biomass shipping will be in the May issue of Biomass Magazine.