Wales’ most productive land looks set to be protected from solar energy development after an intervention by the Welsh Government.

Under current rules, local planning authorities must consult with the government before granting planning consent for solar array developments on 20 hectares or more of Grade 1, 2 and 3a agricultural land – known as Best and Most Valuable (BMV).

New guidance has now been issued to all chief planning officers which suggests that the Department for Climate Change will object to solar development on BMV land unless what it terms as “other significant material considerations’’ outweigh the need to protect that land.

It may not be restricted to large scale development either – the Minister for Climate Change Julie James said her department would comment on all solar applications proposed for BMV land.

The government said it had stepped in because BMV land is considered best for growing future crops for food and for non-food uses such as biomass, fibres and pharmaceuticals.

“It’s a long-term, natural resource important for future sustainability but only accounts for between 10-15% of the land area in Wales,’’ said a government spokesperson.

Yet it is often included in long term solar PV array proposals in Wales.

But the government’s intervention has sparked concern about the impact the policy has on the rights of farmers to diversify into solar energy and there is criticism that the advice is at odds with the government’s own policies on climate change and energy security.

Soil scientist Bill Butterworth said two thirds of BMV land in Wales is down to grassland because of challenges with growing cereals in climate of high rainfall.

Solar development would therefore not impact on food security, he insists, and points out that should the land be needed for food production, the panels can be removed.

“The land can be restored to its original status of productivity, and it can be argued that it will be just as fertile as if it had been under permanent grassland,’’ said Mr Butterworth.

But NFU Cymru supports the government’s position.

"NFU Cymru has a preference for solar farm development on lower quality agricultural land or brownfield sites, avoiding as far as possible development on what is classified as Best and Most Versatile agricultural land,’’ said its president, Aled Jones.

The Farmers’ Union of Wales said it welcomed the government’s recognition of the need to support food production, pointing out that solar panels can be installed on roofed buildings and houses without the need to sacrifice productive land.

FUW policy officer Teleri Fielden said the union had also urged the government to “use the planning tools at their disposal’’ to protect rural communities and farms from land acquisition for carbon offsetting projects.