East Anglia’s farming by-products set to play part in meeting energy obligations

Alternative land use, inventive technology... and poultry litter. All could play a part in helping East Anglia meet its future waste disposal and energy obligations, says rural affairs correspondent Chris Hill.

In the coming decades, the fundamental needs of society will be subjected to a self-compounding series of problems.

Our growing population will devour electricity and food at increasing rates, exerting pressure on finite land resources and fossil fuel stocks.

Farming efforts to feed them will continue to generate waste by-products which will need to be disposed of in a way which preserves the environment for that enlarged population.

These conundrums will form part of the discussion at the Norfolk Farming Conference this week where agricultural experts, food scientists and politicians will discuss potential solutions.

Among the new technologies and efficiency measures on the agenda is biomass – the science of generating energy and fuel by burning organic by-products.

A steady stream of planning applications is evidence of the industry confidence that biomass could play an important role in the county’s energy mix alongside wind, solar, nuclear and traditional power sources.

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Potential fuels include slurry, wood chippings and straw, all of which are driving power plants in East Anglia.

One of the largest is the Thetford Power Station – a 38MW energy generator fuelled mostly by bird droppings from the region’s famed poultry industry.

James Alcorn, commercial manager of Energy Power Resources (EPR) which operates the Mundford Road plant, said it provided an elegant, simultaneous solution to two problems.

Because, while creating a reliable flow of renewable electricity to help meet government targets, it also provides a valuable service to chicken and turkey farmers by clearing their sheds of waste which they could be restricted from using as fertiliser under EU nitrates regulations.

“Here, we burn 420,000 tonnes of product a year,” said Mr Alcorn. “It is a high-moisture, reasonably high-ash product. If there were other by-products around with a calorific value we would look to use them.

“But we need to be able to burn what is available. That is part of the skill – to get something moist and low-energy which just about burns, and turn it into something that burns efficiently in a controlled fashion.

“We are an energy-generating company but the service we provide for the poultry industry is very important.

“They have got to find a way of dealing with their by-products which is bio-secure, but their primary job is to produce chickens and to get the sheds turned around to maximize poultry production. We work very closely with them to make that happen.”

About 80 trucks a day arrive at Thetford Power Station carrying poultry litter, horse bedding and wood chippings from around 300 farms, mostly in East Anglia.

The cargo is dumped onto conveyor belts which feed it into a vast boiler. The extreme heat from the combustion forces steam through a single giant turbine which generates energy 24 hours a day for the National Grid.

Commissioned in 1999, the plant cost the equivalent of EPR’s planned �120m second facility for Thetford, also on Mundford Road, which was turned down in December with “visual impact” cited among the reasons for refusal.

Mr Alcorn said the company was “considering its options” for the site after that disappointment, and maintained that it remained an attractive option when compared to other renewable energy sources.

“The point of our electricity is that it is dispatchable,” he said. “That means we can switch it on and off as we need it, as opposed to other forms of energy where you are dependent on other factors. It costs a lot to run, because we are dealing with high temperatures and corrosive fuels. It is capital-intensive, without doubt.”

EPR also runs the 38MW Ely Power Station, the largest straw-burning power station in the world.

“Straw is another by-product and our Ely plant is based in the heart of the Fens,” said Mr Alcorn. “Ely is in the right place for what it is burning, just as Thetford is in the right place for poultry litter. We pay the farmer for the straw, and we pay him more than fertilizer value for it. But, as much as they like getting paid for it, from the farmers’ perspective it is about the service. He wants the straw cleared as efficiently as possible so he can get next year’s crop in.”

East Anglia is considered ideally-placed to exploit the potential of biomass, with a large proportion of the UK’s pig and poultry farms based in the region. But while some plants burn agricultural waste, others are capitalising on energy crops grown specifically for fuel production.

Philipp Lukas is managing director of Future Biogas, which operates two “anaerobic digestion” (AD) plants at Taverham, outside Norwich. They use a series of processes to break down biodegradable material in the absence of oxygen, generating methane gas to drive electricity generators.

The plant is fed entirely by maize grown on the surrounding 2,500 acres of Spring Farm on Fir Covert Road.

Mr Lukas said: “The AD process is one which can bring power from a whole variety of things from cattle slurry to energy crops to food waste. We have chosen to go the energy crop route, which can be flexibly fitted into the rotation and it offers the opportunity of an interesting break crop. There are fantastic agronomy opportunities.

“Instead of putting something like turnips into the Norfolk four-crop rotation, you can use crops like maize, which has the greatest energy yield per acre.

“It is something that presents itself as a diversification opportunity, where a crop that can improve the yields of a farm’s food crops also helps them diversify into the energy market.

“Just across the horizon are a whole raft of new crops being specifically developed for AD. In Germany they are growing sugar beet and wildflower mixes bred for very high biomass yields, and there is a range of perennial crops which you can grow for AD when you have got fields which are prone to waterlogging or away from the farm.” Mr Lukas said the Taverham AD facility collected methane at the rate of 600 cubic metres per hour, driving an engine which exports power to the National Grid.

“All of the maize is turned into energy,” he said. “There is no wastage, and the only by-product is fertilizer.

“The plant that we have is producing energy all the time and is the equivalent of three or four large onshore wind turbines. It is as efficient as any form of conventional generation. We are generating when the wind is not blowing and when the sun is not shining. “AD was not exactly a positive storyline to begin with. People assume it has got to be smelly and dirty, but actually we have been able to address a lot of those fears and the plants in Taverham have shown people that it is not smelly or noisy. You can say what you like about how it looks, but it has a lot less impact than a 90m high wind turbine on the Cromer ridge.”

Spring Farm owner Oliver Arnold, who grows the maize fuel and operates the plant, said: “I think in time it will prove itself as a valuable break crop. The uptake for farmers has been very positive. There are rotational benefits to growing this, and maize is not a risky crop.

“We run the plant on a day-to-day basis, and we feed it, and we do all the contracting. Within our business, it has added four or five full-time people.

“It has been very exciting to be involved in this project. Farmers are very forward-thinking people, and financially it is not a bad payer.

“It has been incredibly good fun and what I like most is that it has been transplanted from Germany, where they are light years ahead of us in this kind of thing. It is a very quiet and efficient energy production, and that is a big positive.”