Renewable energy consultant James Miles-Hobbs says he is still optimistic that someone will eventually develop an effective combined heat and power plant that will generate energy from chicken muck despite numerous failed attempts.
James, who was offering advice on on-farm renewable energy during a workshop at the British Pig and Poultry Fair at the National Agricultural Centre, Stoneleigh, was asked during his talk about the feasibility of producing power from chicken waste. The Wiltshire-based consultant said he was still looking for an effective solution after a series of disappointments.
"I have tried to find a biomass heating system or a biomass combined heating and power system that will run on poultry manure. I have had quite a few people promise me that they have one, but I have been disappointed quite a few times now. I have seen it installed and six to 12 months after it has been installed it's still not working properly."
He said that one of the biggest problems to overcome was the fact that the manure from poultry attacked the insides of boilers. Nitrous oxide emissions from the boilers were another obstacle to an effective system, he said.
"I am tremendously optimistic still, and I am going to see another one next Tuesday, but I have spent the last five years trying to find something. If we could find a combined heat and power plant that produces electricity and heat and converts poultry muck into ash that would be quite good news. But I haven't found one yet; not one that I could hand on heart say you must go and buy one of those, it is the best thing since sliced bread."
James' talk on renewable energy attracted a packed audience to the workshop. Farmers were clearly very interested in the potential savings offered by alternatives to increasingly expensive conventional heat and power systems. James took his audience through a checklist of steps for anyone thinking of switching to wind, solar, biomass or anaerobic digestion, but he said that before anyone invested in renewable energy they should first invest in energy efficiency. He gave the example of a broiler unit where the farmer had been able to save £4,000 a year on each of his sheds simply by changing the light bulbs. "So before you invest in bits of metal and photovoltaic panels think about saving energy first. It could give you about six to eight months payback, which is a lot better than six to eight years."
The next thing to do, he said, was to have an energy audit carried out. "We are assuming that most people to not want to be power generators. What they want to do is to try to invest so that they are going to produce their energy on their own holding. They don't want a huge power station costing £5 million, producing lots of electricity that goes out to the grid. They have had a fairly significant, to say the least if they are on oil or LPG, increase in electricity costs and increase in oil costs over the last three to five years and they are wanting to know how to contain those costs from rising any further."
An energy audit would identify seasonal variations in usage as well as peak and average usage of energy. A broiler farm, for example, would use a lot of electricity during May, June, July and August for cooling and a lot of energy from November to March for heating. Most renewable energy worked best in terms of investment if it was being used all year round.
A farmer would need to obtain wind speed data and irradiance levels data for his or her farm's location. This information was available on the internet and was essential in establishing whether or not wind or solar power was a viable option in that area. Average wind speed would need to be higher than five metres per second at a height of 10 metres, he said. On levels of irradiance, James said that the further south and west a farm was located in the United Kingdom the better performance it could expect to obtain from photovoltaic panels.
Another consideration, he said, was the cost of connecting to the grid to take advantage of feed-in tariffs. He said the cost could range from £25,000 per megawatt to £3.5 million and was dependant on a farm's location, circumstances and the capacity on the local lines. "One of the bad things about being a poultry producer is you use a lot of energy. One of the good things about being a poultry producer is that because you use a lot of energy you will generally have a fairly substantial line coming to your site already." He said it was possible to negotiate down initial quotes for connection from a distribution network operator. He gave an example of one initial quote that had been reduced from £173,000 to £40,000 by a farmer because he had been able to make separate arrangements to dig the trench required for the cabling on his own land.
On planning permission, he said that planning officers now knew that there was a presumption in favour of granting renewable energy projects, so understood they needed a very good reason to turn down such an application. However, there was some resistance from planning committees under pressure from local villagers.
He warned that energy performance certificates now had implications for a farmer's ability to benefit from the Government's feed-in tariffs. An EPC reading of D or higher was required to qualify for feed-in tariffs. The National Farmers' Union was currently attempting to argue that the restriction should apply only to buildings used for human habitation, not livestock buildings.
James said that capital costs for a renewable installation would probably run to about £3,000 per kilowatt installed or £750 per kilowatt for biomass heating. He said the payback period could run from three to 13 years. PV panels would pay for themselves in seven to eight years. The payback period for anaerobic digestion would be four to five years. For biomass heating systems the payback period could be as little as three years.
He said that after weakening last summer, electricity prices were now rising again. British Gas had recently announced an increase of 15 per cent for the winter. Such increases could have a serious effect on a farmer's costs.
