Powerbroker: Calibro helps solar farms to a place in the sun

Flood plains expertise boosts change in UK planning policy

Calibro have not only persuaded the Environment Agency to withdraw its objection to a 60-hectare (150-acre) solar farm in Devon big enough to power about 10,000 local homes, but we may have helped pave the way for solar farms to be included as “essential infrastructure” in national planning policy for flood risk areas.

Our client JMB Solar’s proposed 49.9MW Langford solar farm is due to come up before the mid Devon planning authority this month. Hydraulic modelling by Calibro helped reinforce arguments that solar panels can be treated as a proxy for wind turbines, even in Flood Zone 3b (FZ3b) areas where permitted development is severely restricted. In January, solar farms were added to EA policy and at the end of the month the government released a consultation document on including them in the National Planning Policy Framework.

Calibro have been a forerunner in pressing the case for the use of flood plains for sustainable, renewable power generation projects, and we look forward to seeing a change in regulations.

Langford solar farm, if approved, will help reduce the UK’s CO2 emissions by more than 20,000 tonnes annually. Our flood modelling showed even a 1 in 20 year flood would not reach the bottom of the panels. Any loss of water storage capacity and flow due to access roads and the legs of the solar panels will be more than offset.

As a bonus, Calibro has proposed “scrapes” or wetland depressions for wading birds, and “swales” – shallow channels – to further protect villages downstream by slowing the runoff of rainwater. There will be badger bridges, grazing for sheep between the panels, and it is proposed that the site revert to farmland after 40 years.

“I think we’ve done a good job,” says Calibro’s head of flood risk and hydrology, Alex Bearne. “We’ve tried to create something positive. And hopefully we’ve played some part in ensuring it becomes policy.”

Site of the proposed 49.9MW Langford solar farm
Site of the proposed 49.9MW Langford solar farm, in Devon, where Calibro has suggested a compromise with the Environment Agency to create wetland ‘scrapes’ for wading birds, looking north.


The proposed wildlife wetlands field on the Langford solar farm
The proposed wildlife wetlands field on the Langford solar farm, in the flood zone of the River Weaver in Devon, looking south.