Knepp Castle in West Sussex is benefitting from solar energy after installing an 856.80kWp ground-mount solar farm on the Knepp estate.

The installation was completed by EPC contractor, Econergy Europe Ltd who faced a race to install the solar array in time to benefit from the higher renewable obligation (RO) before it degressed in April this year.

Despite the project being on the drawing board for some time, planning permission was not expected to be granted until late January 2014 – leaving a six week window to design, build and connect the solar farm.

“It was a very tight timescale, particularly when you bear in mind that a lot of the equipment is built bespoke to meet the differing requirements of each particular project,” explained Richard Molloy, sustainability segment manager at Eaton UK, who worked with Econergy Europe on the project. He continued: “Econergy Europe were confident that it would get planning permission, but you can never be sure until you have the paper work in front of you.”

The two companies decided that the best solution would be to separate the cost of the design phase while the teams awaited the planning permission decision. Molloy explained: “Econergy Europe commissioned that allowing us to undertake the cable calculations, the switchgear designs and the General Arrangement (GA) drawings. We went right to the stage of gaining customer approval on the drawings and had all the orders ready to go as soon as the starting pistol was fired.”

Planning permission for the project was granted late in January, with Econergy Europe primed to install the 3,360 solar module-strong array and Eaton ready to work on the grid connection.  

According to the installer, the modules were split into strings of 24 and connected in series into the inverter, with four strings feeding each inverter. There were seven AC sub collector distribution boards which fed back to seven circuit breakers, which in turn fed a single Eaton Capitole 20 LV switchboard with built-in G59 protection. This fed a 700kVA 400/11,000V transformer, via a 1,250A air circuit breaker and then on to an 11,000v Xiria ring main unit (RMU) which connects to the grid.

The installation was completed and connected to the grid with one week to spare in March. The Knepp Estate has committed to maximise the value of the solar farm and will grade, plough and sown wildflower mix to attract local wildlife.