Grain has the potential to be a cost-effective fuel for small-scale heating systems but there are some practical issues to consider, according to Home-Grown Cereals Authority.

Grain has the potential to be a cost-effective fuel for small-scale heating systems but there are some practical issues to consider, according to Home-Grown Cereals Authority.

The HGCA project, in partnership with the Rural Energy Trust, is looking at a range of combinable crop materials including wheat, oats, oilseed rape and straw pellets.

"A number of manufacturers of small scale biomass heating systems are stating that their systems can successfully combust grain," said Dr Roger Williams, HGCA's assistant research director. "So far, the evidence suggests that this may well be the case, but there are a number of issues to consider," he said.

"Certainly grain has the potential to be cost effective as a fuel. At current heating oil prices, wheat at £75 per tonne can reduce fuel costs by 50pc," said Richard Harvey, Rural Energy Trust and leader of the project.

"The use of lower value material, such as grain screenings, seems to be equally valuable as a fuel. However the higher cost of a biomass heating system and the greater management time required to operate them, needs to be factored against this."

Grain has excellent flow characteristics and a high bulk density compared with many biomass fuels. It is easy to store and access in most farm and near-farm locations.

All the fuels tested in the project produced up to 10 times the ash levels of wood fuels and results have shown that there is a tendency for this to form solid clinker in the burner section of the system.

"This problem can be reduced by selection of the most suitable burner systems, by the correct setting of the control systems and, possibly, by using limestone as an additive," said Mr Harvey.

"However, there are possibilities that the boiler equipment may have a shorter working life when burning grain rather than wood fuel."

Burning grain can produce relatively high levels of nitrogen oxide gases in the flue gas emissions. These products are significant greenhouse gases and could create issues if large scale use of grain as a fuel were to develop.

Data from the study will be also be used to evaluate the environmental impact of grain as fuel. The greenhouse gas emissions resulting from the production of grain will be balanced against the emissions savings of using a carbon neutral energy source.

A five-month project is being carried out by the Cambridge-based National Institute of Agricultural Botany to assess the biomass potential of varieties of miscanthus and of short rotation coppice willow and poplar.