While it would be a mistake to think that farming had ever stood still, the pace of change today is surely faster than ever before.
Alongside improvements in techniques and technology, there are wholesale changes in the very basis on which farms grow crops, deliver an end product and thereby run a successful business.
One example of a business that has taken diversification well beyond the usual ‘barns to offices and a farm shop out the front’ approach is St Nicholas Court Farm (SNCF), based at St. Nicholas-at-Wade, near Birchington in east Kent.
The company already has a 600Kw ground-mounted solar PV array tucked away within the site – and invisible from the nearby road – and is now taking the renewable energy approach to the next level.
The company is working with a German company to build an anaerobic digestion plant that will be capable of delivering 700m3 of Biogas, which is enough gas to meet the needs of 4,000 homes, earning Feed-in Tariffs (FiTs) from the government at the same time.
While MT-energie is completing the highly-specialised task of installing the fully gas-tight, sealed system of tanks and pipework, SNCF called in local experts Torran Construction to carry out the groundworks, lay the drains and build the silage clamps that hold the raw material for the two digesters.
While the usual public perception is that anaerobic digestion takes food waste and turns it to energy, commercial plants such as these are designed to run on maize that is grown and harvested specifically for the purpose.
“The benefit of building the anaerobic digesters on the farm, close to the source of the raw material, is that there is no transport cost, either in real terms – the cost of bringing the maize to the site – or in terms of the impact on the environment that road haulage represents,” explained John Rodgers, who set up Torran Construction in 2004.
“At the same time, using maize to create gas in this way helps to reduce the country’s dependency on carbon-based energy and also gives the company a predictable return on its investment. The market for cereals is so volatile that farmers can never be certain what each year can bring, but that is not an issue when the crop is destined to be turned into energy.
While the anaerobic digestion plans represent a new direction for farming, SNCF remains committed to more traditional crops and has also invested in a new 7,500 tonne grain store on the site, built in tandem with the energy scheme.
SNCF asked Torran Construction, which has expanded beyond its initial core offering of groundworks to offer a complete building service, to act as the main contractor for the site but specified that Robinson Structures should deliver the building.
The choice was a good one, since the two companies had worked together on a number of projects in the past, including a smaller anaerobic digestion plant commissioned by SNCF for a site at Ebbsfleet, close to the old Ramsgate Power Station, last year.
It was partly the success of the first, smaller, scheme, that persuaded SNCF to press ahead with the bigger plans at St Nicholas-at-Wade, and the teamwork shown by Torran and Robinsons ensure that they were asked to work together on both the anaerobic digester and the grain store.
“Good communication is vital on these projects, particularly with building timescales getting tighter and tighter,” explained John. “What you need to do is talk closely, work together and be committed to delivering the project as a whole on time rather than being focused just on your own part of the scheme.
“That’s the kind of relationship we have built up with the team from Robinson Structures and it worked just as well on this project as it did in the past.”
The Robinson team will also be playing its part in the anaerobic digestion scheme, due to be commissioned in November, as the company has been asked to construct a storage building for other organic products – such as rejected potatoes – that may be introduced into the digester along with the maize.
While SNCF’s primary crop is potatoes, it is a mixed arable farm and also grows oil seed rape and wheat, as well as maize.
Robinson Structures’ sales director Edward Gregory explained that the farm had relied in the past on a continuous flow dryer and silos to store grain but had found it “increasingly costly to repair, maintain and operate.”
The replacement is a 60m by 37m building that is 7.2m to the eaves and can be loaded with grain to a height of five metres. Equipped with a state-of-the-art drying floor from Welvent, it can dry 6,000 tonnes of grain or store as much as 7,500 tonnes if loaded dry.
“SNCF wanted to modernise their drying and storage facilities and also needed extra capacity to cope with today’s bigger yields,” explained Edward. “Being able to dry and store the harvest gives farmers more flexibility in terms of selling at the right price, perhaps later in the year, rather than selling the crop immediately.”
The building was designed with doors in the side rather than at the end to give it a flexible future. “It meant we could create a bigger building without having to use a valley gutter, which can cause problems in the longer term,” said Edward. “It also means that we can extend the building in the future, if the need arises, and still avoid a valley gutter.”
Robinson Structures’ contracts estimator Charlie Highton said that consulting the farmer early in the process and working with them to achieve the best possible solution based on the company’s experience was one of its strengths.
He added: “We are always available to undertake site visits in the early stages of a project to provide advice and discuss the options.”
John explained that Torran used chalk on a cut and fill basis to level the site, with Robinson Structures then installing a standard portal frame building on pad foundations. It has pre-stressed concrete wall panels and a 150mm concrete sub-floor overlaid with a hardwood drying floor.
Aside from the lack of a valley gutter, the other innovation included in the grain store design is the vertical cantilevered panels used for the internal partitions.
“In many stores, the panels sit inside or alongside steel RSJs, but this makes it tricky to fill, empty or clean the store without damaging those uprights as they stick out into the space,” explained Edward. “In this case we used panels that are self-supporting by virtue of a large base that is sunk into the floor. It makes it easier to use the building because nothing sticks out beyond the wall at any point.”
Work started on the grain store in March and the building is already holding this year’s harvest after being finished on time and on budget.
One of the advantages of the methane-producing anaerobic digestion plant being built just a few hundred yards away – alongside the return from the FiTs and the payment from the national grid – is that some of the gas can be used in the burners that will be used to dry the crop after a wet harvest.
The anaerobic digestion plant consists of two pairs of tanks, one 28m in diameter and the other 32m across. All four tanks are eight metres deep but have been sunk two metres into the ground to reduce their impact on the landscape.
The maize is harvested and stored in silage clamps that sit behind the two feeder intake buildings. Once it is fed into the first tank the crop produces gas which is sold to the grid. The part-used raw material is then pumped into the second tank to extract any remaining gas and is then spread on the fields.
John explained that Torran had equipped the silage clamps with a sophisticated switchable drainage system so that when the clamps are empty, rainwater drains into a nearby lagoon, but when the clamps are producing effluent, it is diverted into the digesters to extract as much energy as possible from the raw material.
The clamps themselves consist of a tarmac base with pre-stressed concrete bund walls, while Torran also built an access road and installed a new weighbridge at the site.
Gas from the anaerobic digestion plant can be diverted to other parts of the farm complex as well as to the burners in the new grain store, potentially saving SNCF thousands of pounds in energy costs as well as creating a new income stream and reducing its carbon footprint.
Torran Construction now employs around 20 full-time staff along with sub-contractors and is moving soon to new offices at Preston Garden Centre, which the business recently bought and will be running as an additional venture.
As well as working on the digester schemes, the company has been busy preparing sites for large scale, ground-mounted solar PV projects on behalf of Vogt Solar at Manston, Littlebourne, Eastry and Herne Bay.
Robinson Structures, which has become well established in the South East over the past few years, is about to begin work on the steel frame for a new multi-sports arena at Canterbury Polo Farm Sports Club.
“Business has really taken off since we moved into the South East and much of it is repeat work from customers who liked what we did for them the first time,” said Edward. “We have also shown that we can establish a good working relationship with other companies such as Torran Construction.
“Our current projects include a hay barn in Sevenoaks, a potato store in Ash, cattle buildings in Cowfold, Petersfield and Seaford, a school in Seaford and several industrial units in Kent and East Sussex.”