On-farm renewables in the spotlight

Farmers looking to reduce their energy bills should look at energy reduction before considering renewables technology, said Farm Energy Centre consultant Jon Swain.

A 20% reduction in energy use was an achievable target on most farms and energy efficiency was the fastest route to energy savings, he added.

Key tips for farmers include:

1. Measure your energy consumption – you need to know how much you are using to know what energy saving measures are necessary and whether or not renewables technology is worthwhile.

2. Regularly read your energy meters – if you are a big consumer of energy, you can get half-hourly data from your supplier and if you want to identify energy usage on individual pieces of equipment you can submeter them.

3. Benchmark yourself – look at your energy usage in comparison to your business output; for example, how much energy it takes to produce 1kg of chickenmeat. This will help identify any periods when your system has become less efficient.

4. Look out for background energy usage that never seems to turn off – identify this and switch it off. This costs nothing to do and results in massive energy savings.

5. Check thermostats to ensure they are set to the correct temperature and install time switches where possible – overheating or overcooling can result in wasted energy use.

6. Ensure your buildings and equipment are properly insulated

7. When replacing existing equipment, buy the most efficient kit that you can afford to.

Engagement with the local planning authority and community is essential throughout the planning process for renewables.

“It’s critical that you try to get a message out about what your development is – if it changes or is confusing you lose trust,” said Chris Calvert of planning consultant Pegasus Group.

“By understanding your constraints – environmental, local community – and having a good relationship with your planning officer you will start to understand at what stage you have to have consultations and provide noise or ecological assessments.”

Speaking specifically about wind turbine developments, Greg Shillabeer from energy consultant Arcus Renewables said it was now part of government policy for local authorities to identify “areas of search” for wind turbine developments.

“Some local planning authorities are asking for certain height restrictions for wind turbines. It’s best to get good advice early on and get some work done with a constraints mapping exercise.”

Constraints against wind turbines include: housing, power lines, roads, bridleways, paths, telecoms links and aerodromes, to name but a few, said energy and property consultant Josh Pollock from Pollock Associates.

“You need to think about what it’s going to cost you to do the project; it’s not just the cost of the turbine. Once you have planning consent, there are people out there looking to rent sites if you don’t fancy building it yourself,” he said.

Energy crops could act as a gateway to financial backing for anaerobic digestion plants, said Robert Greenow from biogas technology proovider and adviser BioG UK.

“When you go to the financer you want to give them a good idea of what’s going in and what’s going out to make your numbers stack up,” he said.

“Energy crops can underwrite the cost of the plant. Always over-spec your feedstock amounts; if you to borrow money over a 10-year period, make sure you have feedstock contracts for 10 years.”

In addition, financers wanted to lend against guaranteed technology, and producers needed to ensure there were service and maintenance contracts in place for the length of the loan, he said.

He outlined four possible funding vehicles for AD plants:

1. Venture capitalist – generally requires a large share of the plant and 17-22% return on investment annually.

2. Private equity funds – more likely to lend large sums of money for a series of plants. Not likely to lend money towards planning permission and returns of 14-18% required.

3. Banks – offer lower interest rates and often require the farm as security for the funding. It is unlikely you will get 100% of the capital required.

4. Pensions funds/asset finance – lower returns are required. They charge higher interest rates than the banks and often require security and a small share of the plant.

Sugar beet has the potential to be a big energy crop in the future, said KWS product manager Simon Witherford.

“Compared with maize, sugar beet is a very good source of energy for methane because most of the plant can be converted or digested. Beet can digest in 10-14 days but maize takes significantly longer,” he said.

“It’s a highly efficient use of your acreage. It ferments very quickly and the methane yields can be very high.”

Trials were currently being carried out in Germany on the harvesting and storage of the beet for use in AD plants, he said.

“The key is to take as much of the plant as possible – what we want to do is just defoliate rather than crowning the plant. We are looking at a three-stage process of dry cleaning of the beet plant,” added Mr Witherford.

“Whole beet ensiling is the way forward we think; from the German trials we see that you need to go high because you cannot roll the beet. You need the height to get the weight for it to compact on itself.”