WEST HALL, near Cupar in Fife, is a 1450-acre farm with 1150 acres of arable land growing wheat, barley, oats, ware potatoes and broccoli.

But over the past four years Ian Crombie and the Partners of Over Rankeilour Farms have invested in a 225kw wind turbine, a 155kW biomass boiler and a 24kW air source heat pump, so were ideal hosts for an RDI renewable energy open day this week.

Running cold store units and dryers on the farm in addition to funding heating and electricity to the main farm house and two additional properties used by the seasonal work force, made it only sensible that Mr Crombie and his farm manager, John Wilson, look into renewable energy.

After much deliberation, a V27 Vestas wind turbine was chosen, and following a consultation with the local planning authority over the siting of the 32 metre machine, they elected to put it on lower ground in order to reduce the landscape and visual impact. This made securing planning consent easier and quicker - which secured a higher rate of the gradually degressing feed-in tariff - and also meant that the turbine was close enough to the farm steading to be able to utilise the power generated on the farm first before exporting the surplus.

"The final location however came with the compromise of lower wind speeds and an output which can be described as spikey," Ian explained.

In fact the whole installation of the turbine didn't come without its troubles as Ian recounted to those gathered on his farm on Monday: "The turbine was erected in April 2012 but did not produce energy until January 2013 due to a wiring issue. Frustratingly this error wasn't discovered until the grid connection was upgraded to a larger cable and a new transformer and substation were added at substantial cost.

"The original estimate for the project was £550,000, but in total nearer £700,000 was spent. In actual fact, had the initial fault been spotted sooner we would not have needed to replace the cable and the turbine would have been running months sooner."

But the national grid distribution line that the turbine is connected to, which emanates from Cupar, only had 150kW of export capacity. This has prevented any other farms on the line from exporting renewable energy. So despite the turbine having a peak capacity of 225kW, the spare energy has to be used either on site or diverted into the wood chip dryer.

This type of arrangement is becoming more common as the power network in rural areas is limited in terms of what power it can accept. However, District Network operators are also becoming more adept at finding ways to connect distributed generation, for example SP Energy Networks are set to announce extensions to their ARC (Accelerated Renewables Connections) this coming summer.

The capital cost of the biomass boiler and district heating network was £80,000. The boiler is a 155kW Herz and was installed by the Wood Heating Company. The boiler serves the office, the farm house and two properties that are used for seasonal farm workers.

Its circular hopper is raised off the ground on a 'table' allowing the feed augers to run horizontally, meaning that there is no 'dead space' where the wood chip never moves and if maintenance is required then the auger can easily be dropped to the floor. The boiler installed came with a two-year free maintenance package to help ensure that it is running at its best efficiency.

For the last quarter, the boiler produced 74.4MWh, of which 55.8mWh was eligible for RHI. In other words 25% of the heat produced was lost in the boiler room and heat transport piping. OFGEM will only pay RHI on heat that they deem is eligible, which typically means a wholly enclosed indoor climate. The boiler was installed in early 2014 and as such receives the higher RHI rate of 8.8p/kWh.

The wood fuel for the biomass boiler has so far been supplied from wind blow around the farm and it's 250 acres of woodland. The farm currently has 400 tonnes of green wood stored which will equate to 270 tonnes at 25% MC once dried and enough timber to keep the boiler running for about three years.

In order to process the wood a tractor towed chipper is hired periodically. This machine is able to access the logs which have been stockpiled in the woodland and simplifies the management of the chipping process.

Due to the limited grid connection, Ian's farm manager John Wilson came up with the idea to use the 'spare' electricity to heat a wood chip drying system. When the turbine is producing more than 150kW of electricity, the excess is diverted in to two 10kW fans and 65 one kW heating elements. This helps ensure that the moisture content of the woodchip is around 22% which improves boiler efficiency and protects the G59 grid connection with SP Energy Networks and allows the turbine to operate at full capacity. Before the dryer was installed the turbine had to be limited to 150kW, so that it would not trip the G59 connection, and this reduced its operational efficiency.

A Daikin Altherma 24kW air source heat pump system was installed in 2010 at Ian and Evelyn's newly built house on the farm. The system has two 300 litre hot water tanks and is designed to operate with a low temperature under floor heating system. As such the heating system operates at 25 to 40 deg C, while the hot water is set at 50 deg C.

While the installation of the turbine was not all plain sailing, the end result of West Hall's renewable energy conversion - and the money to be re-couped and saved over the years to come - are certainly impressive.