More than 90% of suitable commercial rooftop space in the UK is currently unused for solar generation, but unlocking it could provide enough electricity to power around 20 million homes, according to new research.
A report commissioned by Real Estate, in partnership with Forsters and Push Power Ltd and authored by Cushman & Wakefield, estimates that more than 60 gigawatts (GW) of additional solar capacity could be installed across commercial buildings.
The potential output is equivalent to almost 20 times the generating capacity of Hinkley Point C, once the nuclear power station is operational, according to the report. It would also provide more than 10 times the capacity expected to be required by the Government for AI data centres by 2030.
The findings are based on data and responses from 70 real estate organisations representing more than £500bn in assets under management. The research found that only around 3–5GW of solar capacity has so far been installed on suitable commercial rooftops.
The report argues that increasing rooftop solar could help expand renewable energy production without relying as heavily on solar farms on agricultural land. It could also reduce energy costs for businesses and provide landlords with additional sources of income.
The potential is particularly significant for industrial and logistics buildings, where solar deployment remains well below its technical potential.
The research suggests there is already a strong financial case for many installations. A typical 300 kilowatt-peak system costing around £250,000 could provide a first-year net yield of 20% when funded by a tenant, with the initial investment paid back in around 5.5 years. A landlord-funded installation could deliver a 12% first-year net yield and an eight-year payback period.
Either approach could also save an estimated 53 tonnes of carbon dioxide equivalent each year.
However, the report says a range of financial, regulatory and practical barriers are preventing wider deployment. These include complex commercial leases, uncertainty over tax and Real Estate Investment Trust rules, insurance requirements, grid connection delays and inconsistent arrangements for selling surplus electricity.
Although 85% of respondents expect commercial rooftop solar activity to increase in the coming years, the report warns that policy changes will be needed to achieve large-scale growth.
It makes seven recommendations, including removing tax and regulatory barriers, standardising legal agreements such as power purchase agreements, creating consistent insurance requirements and improving the financial returns available for exporting electricity.
It also calls for faster grid connections, greater long-term policy certainty and an increase to the current 50kW threshold for permitted development of larger solar installations.
The report argues that rooftop solar could become an important part of the UK’s future energy system, helping improve energy resilience while reducing emissions from the built environment, which it says currently accounts for around 25% of the UK’s greenhouse gas emissions.
Rob Wall, Assistant Director, Real Estate:UK said: ‘Solar energy has a critical role to play in the UK’s energy transition, and commercial real estate has the potential to be a major player in the generation of rooftop solar. However, as our research shows, deployment of solar on commercial buildings is slow and we are still some way off from delivering that long promised rooftop revolution.
‘There is ambition – with 85% of real estate professionals expecting solar power generation from commercial buildings to increase over the next 24 months – but for that to happen we need a series of policy reforms as set out in today’s report.’
Photo: Florida Solar Fix