MORE than half of the solar panels required to hit government net zero targets could be fitted on rooftops and car parks, a major new report for CPRE, the countryside charity, has found.

The research, by the UCL Energy Institute, shows that decarbonising the grid requires far less land than previously feared. 

The government is advised to set a national rooftop solar target of at least 40GW by 2035.

Installing solar panels unobtrusively on existing buildings and car parks would enjoy near universal public support and help minimise objections to large solar farms in the countryside, the report says.

The potential of urban brownfield sites to generate renewable energy is being dramatically underutilised at present. 

A series of crises, including energy security, food security, climate change, nature recovery and housing, have placed the countryside under intense pressure.

The report concludes that, in order to transition to renewable energy in the timeframe required, there is no alternative but to accept ground mounted solar projects will be necessary.

However, it offers hope that valuable landscapes can be protected, the need for additional large greenfield schemes gradually removed, and contentious planning disputes avoided if rooftop solar is prioritised.

The government has set a national target of 70GW of solar energy generation by 2035.

The independent review analysed and quantified the solar photovoltaic capacity of rooftops and car parks across England, providing an assessment of the total energy that could be generated. 

The key findings are: 

• Installing solar panels on existing rooftops and other land such as car parks could provide at least 40-50GW in England by 2035; and 

• Longer term to 2050, and with further investment, there is potential for up to 117GW of low carbon electricity to be generated from roofs and other developed spaces.

CPRE is calling on the government to ensure all suitable new buildings have rooftop solar as standard.

Regulations should be updated so that solar capacity is a requirement of planning permission for major refurbishments and new residential, commercial and industrial buildings.

Roger Mortlock, chief executive of CPRE, the countryside charity, said: "We are missing a trick in failing to install more solar panels on roofs and car parks.

"Rooftop solar has almost universal public support. It’s unobtrusive and largely out of the line of sight, which means less objections and a speedier passage through the planning system.

‘Given the urgency of the climate crisis, it’s time that renewables are fitted as standard on all new development. Homeowners expect it on new homes and it’s crazy to see massive new warehouses, with roofs the size of football pitches, waved through without any expectation they install rooftop solar.

"The planning system is stuck in the fossil fuel age without a plan for net zero. The first step must be all new buildings and major renovations requiring solar panels as a condition of planning permission unless there are strong reasons not to."

If the government fails to kickstart a rooftop solar revolution an area of countryside larger than the size of Greater London will be required for ground-mounted schemes.

CPRE’s view is that this land could be much better used for either nature recovery, public access or low impact food production; or a mixture of these.

With the right policies, rooftop solar could hand power back to the people. A decentralised future of renewable energy cooperatives sprouting up in communities across the country, supported by the government, is a realistic option in a net zero world.

The report’s key recommendations to reach the government target of 70GW of solar energy by 2035 include:

• A new rooftop solar target: at least 40GW by 2035 delivered through the lowest cost opportunities on new builds, commercial buildings and car parks; 

• Land use framework: a national strategy to balance the competing needs for buildings, carbon sequestration, energy and infrastructure, food security and nature recovery on a finite amount of land; 

• "Roof first": local communities can audit solar potential on available south-facing roofs, following the example of Kendal Town Council in the Lake District, and then will be able to prioritise solar panels on suitable brownfield land and avoid best and most versatile agricultural land; and 

• Grid capacity: work with Ofgem to require Distribution Network Operators across the country to invest in local grid capacity to better accommodate increased generation from solar and heat pumps.

Prof. Mark Barrett of the UCL Energy Institute, lead author of the research, said: "This study found there is more than sufficient potential solar capacity on rooftops and car parks in urban areas.

"It’s clear we can get close to meeting the government’s solar energy target without necessitating the development of large solar farms in sensitive rural areas.

"Urban photovoltaic panels on car parks, and new and large buildings, would be relatively cheap although retrofitting solar panels onto existing homes would be more costly."