Nottinghamshire County Council looked to EvoEnergy for help overcoming a power export limit at Hagg Farm, an outdoor education centre for young people in the heart of the Peak District. The 32 kWp system was installed by EvoEnergy in September, making the council the UK’s first to adopt an export power limiting system on a PV system.
Because of its location in rural Derbyshire, powered only by overhead lines, the team at Hagg Farm was told that the array must stay below an export limit of 7kWp, to reduce the strain on the National Grid by the Distribution Network Operator (DNO). That would have meant reducing its size by 75 per cent.
However, EvoEnergy’s project management team had the idea of fitting an Export Power Control (XPC) system on site. This solution, has helped the council to overcome one of the biggest barriers to the future integration of renewables systems into the existing power network.
The EPC system is comprised of conventional controls used in industrial automation. It can be implemented on virtually any size of solar array alongside inverters from a variety of leading manufacturers. With it now in place, the centre will now benefit from up to 25,000 kWh of self-generated energy per year, equivalent to a 13-tonne annual saving in CO2 emissions.
Tim Hickman, technical manager for EvoEnergy, said:
“There was no ‘off the shelf’ solution to the export limit problem at Hagg Farm so our technical team had to develop something new to meet the needs of this project and others where we’re faced with similar limitations. The XPC ensures that the export power never exceeds 7kW for more than a few seconds – it’s an inventive answer to what is becoming a common requirement of the electricity network operators.
As the Grid becomes increasingly congested with renewable systems, the issue of managing diversified power generation across the network isn’t going away’. We expect many more businesses and organisations to be faced with a limit on the size of their next array because of export limits, despite the fact that many will consume the majority of the power their solar system produces.
An EPC, however, allows firms to still install large solar arrays by reassuring DNOs that the level of exported power is controlled and the electricity network will not be put at risk. This way the business can still benefit from the significant offset of imported energy costs during the daytime.”
The install was completed in less than two weeks and involved a team of five working on fragile slate roofs; some more than a century old. By using the SolarFlash™ system for slate roofs, the integrity of the roofs could be maintained to ensure compliance with the Microgeneration Certification Scheme.
Phil Baker, Head of Hagg Farm, said:
“EvoEnergy worked hard before the project to come up with a solution that met our requirements and were helpful and efficient throughout the install. They also commissioned a display that informs the young people about the energy savings to improve their understanding of sustainability – this is just as important as the financial savings to the centre’s budget.”
Phil Keynes, Energy Team Manager for Nottinghamshire County Council, added:
“We were really pleased that EvoEnergy found a solution which enabled this installation to go ahead successfully. The centre was very keen to have PV as a showcase for renewable energy technologies. The PV at Hagg Farm are part of the Council’s £1.8million investment programme in solar panels, which is itself part of a wider programme of investment in renewable energy and energy efficiency across its estate.”