영국 노포코의 양계 농민이 녹색에너지를 생산

Nigel Joice poultry farm tour. Photo: Emily West Photography

For the first time since the business invested in renewable energy strategy three years ago, it produced more power than it consumed.

Mr Joice, and his son, Patrick, welcomed young poultry producers to Uphouse Farm, South Raynham, near Fakenham. They told the 30 members of the joint National Farmers’ Union and ABN poultry industry programme that the primary goal was to produce quality chickens and minimise energy consumption.

Since 2010, they have invested in an energy centre, to warm the growing chickens, and installed solar panels.

The three arrays of photo-voltaic panels, rated to produce 450kW and mounted on roofs and on the ground, made the farm energy-positive for two days earlier this year.

Mr Joice, who started as a chicken producer in 1997, runs his flocks of birds on two self-contained farms with a team of three staff on each. To maintain strict bio-security, the staff only work on their “home” farm, he said. In a year, the 115-hectare arable farm finishes about six million table birds, roughly 12 million kg of chicken. It consumes about 20,000 tonnes of poultry feed.

The chickens produce about 8,500 tonnes of litter each year, which was a further challenge in the drive for energy production, he added.

When they started the first phase of the renewable energy strategy in 2010, two 500kW furnaces were installed to heat water for the poultry houses. For the first year, they burned woodchip but since the middle of last year, the fuel was chicken litter.

“This is under a special licence from the Environment Agency because we’ve been testing emissions,” said Mr Joice. “It has all been extremely successful and emissions have been extremely low. We’re amazed at the performance.”

There has also been another major benefit, said his son, Patrick, in terms of better poultry welfare because of the drier heat in the chicken sheds. “We didn’t think we’d get such a similar level in the improvement of the birds and their welfare. It has come as a bonus. We’ve got a better environment in the chicken sheds and they’ve rewarded us with better performance.”

He compared nine chicken crops, in a typical 50-day flock cycle, heated by LPG (liquid petroleum gas) and using the dry heat from the energy centre.

“We’ve seen a six point improvement in the food conversion rate,” said Mr Joice, who had spent £120,000 a year on LPG.

The farm, which was last year’s champion Norfolk Farm Business, was also the 2011 Farmers Weekly Poultry Farm of the Year.

As the farm produces about 8,500 tonnes of chicken litter a year, the aim was to burn the surplus to generate electricity. Mr Joice said about 2,500 tonnes was needed for heating but the rest could be generate electricity. In January his electricity bill was about £13,500.

The furnaces, installed by Irish specialists, bhsl, heat water to 85C for circulation to the chickens..

Patrick Dight, who is bhsl’s applications director, said that a new technique to burn litter on a smaller scale had been developed more than 11 years ago. Their design of fluidised bed combustion of poultry litter, used in big power stations, has operated consistently for months. It burns at more than 600C, he added.

“Chicken manure is not an easy product to manage. It was very difficult to handle because it is like shavings, honey and glue mixed together. It has high levels of ash and silica, variable moisture content and a low calorific value,” he added.

The manure is stored in a bio-secure area, under negative pressure to contain odour, before it is burnt – and the operation is monitored at bhsl’s headquarters in county Limerick.

“Our priority is the birds’ welfare. We have to maintain a set temperature of water to the birds at all times,” Although there is a back-up boiler, it has never been needed,” he said.