Amaizing crops could produce electricity for Norwich

High-yielding crops of energy maize could be producing "green electricity" for thousands of homes on the edge of Norwich.

Three new varieties have produced astonishing yields in a national trial at Oliver Arnold's Spring Farm at Taverham.

Plans have been submitted for a £2m investment at the farm, off Fir Covert Road, involving energy specialist Cosigas, that would generate electricity for about 2,500 homes. The 1mW biogas plant would ferment about 1,000 acres of specially-grown energy maize to power a generator to make electricity by burning the gas produced in the fermentation process.

Mr Arnold, who hosted the national trial, has grown eight acres of energy maize varieties to assess yields.

"It has not been the best year, given that we've hardly had any rain since the middle of July. Although the crops has almost died it has produced fantastic yields," he said.

Plant breeder KWS was the first in Europe to develop specific energy maize varieties alongside its more traditional grain maize and forage maize breeding programme. For the past 10 years it has developed higher-yielding energy varieties to meet demand in Germany and other European countries. These varieties are bred for maximum yield rather than to produce more palatable crops for feeding to dairy and beef animals.

The Arnold family farm plans to grow more energy maize as a potentially clean, environmentally-friendly fuel source that would be produced in an anaerobic digester (AD). Mr Arnold, who is also a contractor employing 11 staff, grows about 70 acres of forage maize to feed his beef cattle enterprise. He already has firm interest from many local farmers keen to grow energy crops.

Cosigas specialist Dr Joachim Lukas said there were about 5,000 ADs in Germany. The project had many other potential advantages, he added.

"It is a good soil improver. If you harvest 20,000 tonnes of energy maize whole crop, you return about 4,000 tonnes of solids, which is a good thing. In that sense it is more sustainable than other agriculture-based fuels," he said.

"Essentially, it is a closed system. If you use the biogas to run cars and compare it to bio-ethanol or biodiesel for the same area grown, you would drive about twice as far with biogas. That is the best indicator of energy yield per hectare, which is really the important figure," said Dr Lukas.

"The advantage of using AD is that it runs 95pc of the time, unlike a wind turbine. And, by producing biogas, you get nearly 50pc out in electricity, which is a huge difference. And, by producing bio-methane, once the CO2 was removed, then it could be put into the national gas grid; and that's another alternative."

Mr Arnold said: "We're very excited. There's a lot of misconception about bio-digesters. Everyone will see that it doesn't smell and doesn't make any noise. For farmers with poorer land it can provide an income. It is a win-win situation for farming."

At Denham, near Eye in Suffolk, farmer Oliver Knowland, who is also with Cosigas, said the "energy-in and energy-out ratio was 20 to 1". He added:"It is absolutely fantastic. That's why it ticks so many boxes.

"This is very much a virtuous circle: crops grown on the farm, used material back on to the land, and an efficient way of producing electricity from home-grown energy."

Mr Arnold said: "If you'll drive past this farm you'll never see it. The process is amazingly quiet; the rustling of these leaves in the wind

is far noisier than the engine will ever be."

The backers have submitted a planning application, which will be considered by Broadland Council on on November 4.

giant crops impress expert - See page 46.