STOWELL FARMS: Investment in Anaerobic Digestion Confirms Dairy Viability

After attending a biogas exhibition, Farm Manager Gavin Davies teamed up with EnviTec Biogas in 2011 to develop an Anaerobic Digestion (AD) plant.

Online PR News – 25-October-2012 – UK – The Background

Stowell Farms in Pewsey, Wiltshire, was faced with finding significant capital investment to improve the dairy unit at East Stowell and to comply with changed slurry storage regulations.

There had been little investment in the dairy facilities for a long time, and the unit was no longer considered viable.

Farm Manager Gavin Davies thought about moving out of dairy altogether, but increasing consumer interest in food produced in the UK to higher welfare standards, coupled with rising consumption of dairy products globally, convinced him the industry as a whole had a future.

Topography and area of the site, however, limited the potential size of the herd, which would have delivered a poor return on investment.

Gavin researched complementary additional income streams that would add significant revenue and support the commercial viability of a herd of 500 cows.

After attending a biogas exhibition, he teamed up with EnviTec Biogas in 2011 to develop an Anaerobic Digestion (AD) plant capable of producing 4.1 million kWh of electricity and 3.55 million kWh of surplus heat.

EnviTec started work on the plant in 2011, and it came online in September 2012. It played a key part in securing investment in state-of-the-art cow housing and handling infrastructure.

Electricity produced by the plant will be used on the farm and sold to the grid under the 20-year Feed in Tariffs. About 85 per cent of the electricity will be exported, the balance being used on the farm.

Heat will be used on the farm, and there are plans to pump the surplus to a leisure centre and two schools in Pewsey.

The EnviTec plant will generate revenues of more than £750,000 and return on investment is expected within seven years.

The Business

Stowell Farms is a beef, sheep, arable and dairy operation. About 3,250 acres are used, some under contract.

At full capacity, the dairy herd will be made up of 500 animals.

Between 600 and 700 acres a year is given over to maize. The intention is to produce about 8,000 tonnes of silage to feed the AD plant and 4,000 tonnes for cow feed.

On-site silage production and slurry mean no feedstocks have to be bought in to supply the AD plant.

Marginal grassland could also be given over to maize, using the grass as a buffer.

The AD plant is run as a standalone business.

The Plant

Maize silage, cow slurry and waste feed are pumped into a sealed digester tank. The material is heated, and the resulting bacterial activity produces biogas – about 60 per cent of which is methane.

The biogas fuels a Combined Heat and Power (CHP) unit which drives a generator. Electricity produced by the generator is sold to the grid and used on the farm.

The engine cooling system produces hot water. Some of this hot water is used to heat the digester, some will heat farm buildings and it is hoped some of the heat will be transferred to the schools and leisure centre in Pewsey.

Digestate produced at the end of the process can be fed back into the system or separated into liquids and solids. Liquids are applied to grass and arable crops as a high-quality fertiliser – helping to cut costs significantly – while solids are stored for application to arable stubbles.

Gavin Davies, Farm Manager: “The revenue and savings from producing your own heat and power are considerable, but the benefits are much more wide-ranging than this.
“An AD plant helps with slurry management, which means there’s no need for a lagoon and that in turn reduces odour.
“The digestate produced at the end of the process saves us a lot of fertiliser costs and unlike slurry the nutrients are readily available.”

John Day, UK Sales Manager for EnviTec Biogas: “Gavin’s passion for dairy and for farming as a whole was obvious.
“We worked with him to come up with a scheme that would secure the viability of the dairy facilities and de-risk the business for many years.”

The Wider Investment

The EnviTec Biogas AD plant was critical to persuading lenders that the dairy at Stowell Farms had a bright future.

Significant, predictable long-term income from the Feed in Tariffs (FiTs) helped secure funding for 75 per cent cubicle and 25 per cent straw yard housing for up to 500 cows, with state-of-the art milking and handling facilities.

A viewing gallery and education room overlook the parlour, and new office accommodation is in the same building.

In addition, finance went towards feed storage buildings and silage clamps, ensuring Stowell is self-sufficient in feedstocks.

A house and a flat were built to accommodate the herd manager and an assistant.

The Benefits

For the business:

Revenue of more than £700,000 a year.

Long-term, predictable income from the 20-year FiTs allows longer-term investment decisions to be made.

Field application of digestate eliminates the need to buy 400 tonnes of manufactured fertiliser a year.

Comfortable cow handling and housing facilities ensure high welfare standards.

Jobs have been saved.

Several new jobs have been created.

The future of milk production on the estate has been assured.

Gavin Davies: “The AD plant has secured milk production at Stowell. It’s also secured the existing workforce and allowed us to take on additional full- and part-time employees.
“Farming is a commoditised business, so predictability of income is at a premium, but the income and savings we get from AD are pretty much set and they are long term.
“That allows us to make much more informed and forward-looking business decisions.”

John Day: “The Government wants farm-based AD plants to be an important part of the renewable solution. But the success of that long-term vision is dependent on the viability of agriculture as a whole, and policy-makers have to realise this.”

For the community:

First-class educational facilities provided by the education room and the viewing gallery. Hundreds of schoolchildren, Young Farmers and residents from across the region have already attended Open Farm Sunday at Stowell. AD tours have also been organised, and lambing tours are planned.

Land next to one of the primary schools is being used for class projects.

Gavin Davies: “I am absolutely passionate about improving the image of agriculture. It’s the responsibility of farmers to do that by educating not just the youngsters, but the teachers and the bankers as well.
“We had hundreds of people here for Open Farm Sunday and you see people going away with a completely different attitude.
“Dealing with the public and overturning the negative attitudes towards agriculture are our own responsibility.”

For the environment:

Clean, green energy that helps with emissions reduction targets and the Government’s aim of having 1,000 farm-based biogas plants up and running by 2020.

The Bigger Picture

Gavin Davies is passionate about the image of farming and its long-term viability – and he believes renewable energy can play a vital part in improving both.

The education facilities and the plant itself will be used to educate bankers and land agents about the potential for AD projects to transform farm businesses and to underpin wider investment in farm infrastructure.

Gavin Davies: “We approached three banks, and two of them hadn’t really got the faintest idea about AD. In fact, backing the AD side of a dairy business should be a no-brainer because it’s almost index linked and for us it represented a better investment than wind or photovoltaics.

“People see farmers in the UK who develop AD plants as being forward thinking – but go out to Germany, it’s been working there for years.

“It’s straightforward, it’s proven and it’s no-risk.”


For more information, or to arrange an interview, contact David Johnson at Shepherd PR by email or call 01335 368020.