Waste wood is an untapped resource for biomass fuel, according to a new study in the U.K., which said that most of the 10 million tonnes of waste wood being produced in the country is tossed out with the garbage.

The U.K.'s Department for Environment, Food And Rural Affairs, or Defra, which released the report, estimated that recovering energy from just 2 million tonnes of waste wood could generate 2,600 gigawatt hours electricity and save 1.15 million tonnes of carbon dioxide equivalent emissions.

"The key to realizing this potential is more, geographically dispersed, Waste Incineration Directive compliant combustion facilities delivering both energy and heat recovery," said the Defra study.

The Waste Incineration Directive is an EU directive aimed at minimizing the environmental impact of incinerators.

A recent report from New Zealand said biomass could be the answer to a bulk of that country's future energy needs (see New Zealand report touts biomass for energy needs).

The New Zealand study said purpose-grown energy forests, if planted today, could meet all of the country's future transport fuel and heat energy needs, without threatening the country's important agricultural industry.

In the U.K., the waste wood that could be used as biomass is usually thrown out as part of a mixed waste stream, and the department said there is limited availability of facilities for separation.

The bulk of the waste wood is coming from construction and demolition, municipal solid waste, and commercial and industrial waste.

Defra pointed out that while there's been a rise in the use of recycled wood in the country, much of the waste wood has too many contaminates, such as fixers, paint, screws or coverings, for recycling.

The principal recycling outlets for wood are in the panel board industry, animal bedding, equine surfacing and garden mulches, and most recyclers require high grades of waste wood.

The wood could be sorted or cleaned, but the study said "it is not believed to be cost-effective, if even possible, to remove all contaminants from low grade waste wood."

The main wood recycling industries can't even touch waste wood which has high levels of contaminants, such as plastic coatings and resins.

The panel board industry is restricted in the use of processed woods, such as those containing melamine, for the manufacture of panel board, and animal bedding users need a product that's free from contaminants.

"Historically landfill was relatively cheap and benefited from low processing costs as all grades of waste wood (excluding hazardous) could go to landfill," said the study.

But landfill tax has increased significantly in recent years. It's at £24 per tonne now and is expected to rise by £8 per tonne per year over the next three years.

"Furthermore there is a scarcity of landfill in some parts of the U.K. which means that landfill gate fees are also increasing," said Defra.

Right now, there isn't much infrastructure to deal with the waste wood, even if it could all be separated.

Defra said there are 105 Waste Incineration Directive compliant incineration plants on the island, but only one plant is known to accept waste wood, in Slough.

Three more are under construction or commissioning in the U.K., in Shotton, Lockerbie and Teeside.

All but the planned Lockerbie plant are combined heat and power facilities, with the Slough plant producing 20 megawatts of electricity, while the other three are expected to produce from 35 MW to 44 MW of power.

But more will be needed if all of that waste wood is to be diverted from landfills.

The study said that Germany introduced a landfill ban on untreated biodegradable organic waste in 2003.

"In the U.K. a ban on waste wood to landfill would provide the market with incentives to construct diversion facilities," said Defra.

But even if the incentives are put in place, don't expect to see waste wood-burning biomass plants popping up everywhere.

"There is a tension between pressure to locate such plant close to potential users of its waste heat – who may often be found in towns and cities – and the need to protect air quality," said the study.

Defra said future waste wood-burning plants are more likely to end up at industrial sites away from major centers of population.