Pig farmer James Hart and his chicken farming neighbour Jeremy Iles have just passed the first anniversary of installing an anaerobic digester on their farm near Fairfield, Gloucestershire. James pronounces the project “a success” despite the hard work involved and last month earned £25,000 in sales of surplus electricity to the National Grid.
James and Jeremy decided to join forces several years ago to develop new income streams from their businesses. Utilising animal waste from their farms seemed an obvious answer – they took the decision to build their own anaerobic digester (AD) to generate electricity from chicken, cow and pig manure and slurry.
The pair undertook several research trips to Germany where there are far more AD plants used on farms.
“We looked for English equipment wherever we could, but it wasn’t always possible as AD is pretty new in this country. The renewable energy market is much more developed in Germany and they are further ahead.
We knew we needed gas analysis equipment to monitor the mix of gases produced as the digestate broke down so we spoke to Gas Data. They had a proven solution in their Click! system that was the same price as the German one, so we chose them.”
Gas Data’s Click! System modular fixed gas analyser is a simple way of on-line monitoring and analysis of biogas that gives users like James greater flexibility over traditional monitoring systems. It is totally modular so where one component fails it can be removed easily then repaired quickly and efficiently. Customers benefit from a more cost effective operation as they have less down time.
The farmers filled the digester for the first time on 1st March 2011. The electrical connection was made on 15th March and then it took a few days to get up to temperature – it needs to be at 40 degrees Celsius. The engine was commissioned on 4th April and on 5th April James and Jeremy sold their first electricity back to the grid.
It took several months to understand the best mix to optimise methane production and therefore produce the most electricity.
“It’s a bit like making a cake, there’s a recipe we now use, 35 tonnes a day liquid pig slurry, 5 tonnes a day of chicken litter, 2 tonnes farmyard manure and 6 tonnes of maize silage. This is based on the product we have available from our farms and we then use maize to balance the mix.
The Gas Data equipment allows us not only to analyse the amount of methane produced but crucially the hydrogen sulphide – a very corrosive gas that will lead to the engine breaking down. We only make money when the engine is running so we can’t afford any down time.”
So the project stacks up financially. Of the electricity generated, 50 kilowatt hours are used on site and 250 sold – enough to power around 200 homes. The plant also powers the farm and produces a fertilizer by-product thereby saving money, not to mention the ‘green’ credentials of reducing the farm’s carbon footprint.
So what’s stopping other farmers getting behind AD?
According to James the capital costs are very high. Their plant cost £1.2m and relied on a grant from the Rural Development Programme. The returns are also less generous than in the rest of Europe. UK producers get between 16p and 17p per kilowatt but in Germany the return is 21p per kilowatt.
However it does pay if it’s done right.
James is positive on that point:
“Our income last month in electricity sales was £25,000, so that goes back to pay off the bank, and we are on target to pay off the loans within five years. Farmers should consider it, but there are risks involved and it’s not suitable for everyone. It’s hard work – like all of farming. But it is fun.”
Building on its experience with Glebe Farm and other agricultural AD projects, Gas Data has now developed the On-Farm Biogas Analyser variant of the Click! System. This provides the key features required in this application in an easy to use and rugged format. Perfect for use on working farms.
To discover how Gas Data can support your AD development call us today on +44 (0) 2476 30 33 11 or email email@example.com