1 November 1996

Heat is on for multi-purpose miscanthus

MISCANTHUS is to be used to fuel a heating system at Rosewarne College in Cornwall.

This is believed to be the UKs first miscanthus-fuelled system and the only one in the EU designed specifically for burning the crop.

The project has qualified for grants under the EUs Objective 5b scheme for stimulating the weaker rural economies, and from MAFF. Some of the consultants involved have also contributed time and resources.

They include Carolyn Wilkins, who says miscanthus is an ideal biomass crop for energy, particularly in west Cornwall where it outyields both willow and poplar. "We see it as a multi-purpose crop for energy, fibre or mulches."

Dr Wilkins is studying the environmental impact of growing and burning miscanthus, especially the trace elements and heavy metals. Miscanthus ash from the project will probably be pelleted alone or after mixing with other materials, and evaluated for use in reclaiming derelict land.

Sarah Redstone, another independent consultant, first became involved with miscanthus while on an EU Leader-financed project developing and operating a tissue-culture service for Cornwalls nurseries. She worked on propagating miscanthus by seed instead of the labour-intensive collection and planting of pieces of rhizome.

Standard equipment

Dr Redstone has a collection of miscanthus types for seed production and, with the help of Rosewarnes farm staff and facilities (part of the Duchy Colleges horticultural department) is trying to develop mechanised collection and planting of rhizomes using standard farm equipment.

She believes the main potential for miscanthus as an energy crop will be in small-scale schemes rather than those operated by big companies and utilities. For the Rosewarne heating project it will be big-baled. Chopped Miscanthus is too prone to composting during storage. Typical annual yields at Rosewarne have been 7dry t/ha in year one, and double that by year three, though output varies with season. The crop is normally harvested in February/March.

The engineering aspects of the project are being studied by Bob Watson of ADAS. He aims to use only off-the-shelf components so that anyone can easily obtain them if they wish to install a system.

It is hoped the Rosewarne plant will be in use early in 1997. Visitors will see the parts of the site considered suitable for heating by miscanthus, and will learn the options available and why this one was chosen. Costings will be regularly updated.

"We are all fully independent and will tell it, warts and all. Visitors will be able to see miscanthus propagated, grown, harvested and used as fuel", said Dr Redstone.n

John Burns

Carolyn Wilkins in an area of miscanthus destined for small-scale power production in Cornwall.