The UK’s solar and energy storage sector is facing a worrying situation: the lack of clarity in the proposed capacity limits for 2035 could result in a significant loss of investment and delays in decarbonising the electricity system.

“It is unclear whether the 2035 targets should be considered as strict limits or merely approximate goals,” says Gareth Simkins, Senior Communications Adviser at Solar Energy UK, to Strategic Energy Europe. This regulatory ambiguity puts numerous projects currently in development at risk, particularly beyond 2030, when many initiatives could exceed the current limits.

At present, the target for solar energy connected to the transmission grid is set at 17 GW for 2035, a figure the industry considers insufficient. “We need that target to be increased, and we also need more allowance for batteries, as additional capacity expected to be built between 2030 and 2035 is less than two GW. That is extraordinary considering that there are already individual projects exceeding one gigawatt,” emphasises Simkins.

The sector fears that these restrictions could slow the pace of investment in renewables in the UK, affecting its competitiveness compared to other, more dynamic European markets.

Regulatory Reforms to Speed Up Solar Development

In case lobbying efforts do not succeed in amending these limits, the industry is exploring alternative regulatory measures to accelerate project implementation and mitigate the impact of these restrictions.

One of the most notable reforms is the modification of the threshold for grid impact assessments. Currently, projects over 1 MW must undergo a detailed analysis of their impact on the transmission network, which increases development costs and timelines. However, there is a proposal to raise that threshold to 5 MW in England and Wales, eliminating unnecessary bureaucratic barriers.

“This measure will cut costs and accelerate projects, allowing for a faster transition from conception to implementation,” explains Simkins. However, this reform has not yet been extended to Scotland, where the transmission and distribution system operates differently.

Growth of the Commercial Rooftop Solar Market and Its Underrepresentation in Statistics

One of the fastest-growing segments of the UK solar sector is commercial rooftop solar, which is not fully accounted for in the government’s official statistics.

“There is a gap of around 3 GW in the official figures. The government reports approximately 17 GW of installed solar capacity, but industry data suggests the actual figure for the end of last year was 20.2 GW,” warns Simkins.

The lack of proper tracking for these projects prevents an accurate assessment of the sector’s growth and underestimates its impact on the energy transition. Some of the largest projects currently in development include a 31 MW plant at the Port of Liverpool, which will far surpass the 6.5 MW record at the Port of Hull.

The Issue of Grid Connection Delays and Network Congestion

Another critical obstacle is the long waiting times for new solar projects to be connected to the grid. Some initiatives have been given connection dates as late as 2042 or 2043, posing a major barrier to sector growth.

“In 2023, the government published the Winserr Review to speed up grid connection times. Its measures are expected to halve waiting periods, but if the waiting time is still a decade rather than two, it remains a huge problem,” warns Simkins.

One of the solutions currently being implemented is a new grid management system by the National Energy Systems Operator (NESO), which prioritises projects that are ready for execution while removing those that lack financing or advanced permits.

“This change is positive, but there is still uncertainty about how it will be fully implemented,” adds Simkins.

Economic Opportunities and the Sector’s Future

Despite these challenges, the UK solar sector continues to offer significant economic opportunities. One of them is the domestic production of key components, such as cabling, support structures, and energy storage systems.

“The UK has great potential to manufacture batteries and other essential components, representing a huge economic opportunity,” says Simkins. He also highlights the growth of innovative technologies such as thin-film PV, which is already being produced in the UK.

To capitalise on these opportunities, the industry is promoting initiatives like Solar Careers UK, a programme aimed at attracting new talent into the sector. Its first event will take place on 5 March in London, bringing together schools, universities, and government representatives.

Additionally, strategies are being developed to integrate solar energy into the new energy efficiency regulations for homes and buildings. While their implementation is not yet confirmed, it is expected that these new standards will drive the adoption of solar panels in new constructions.

Electricity Market Review and Its Impact on Investment

Another key factor in the future of the UK solar industry is the Review of Electricity Market Arrangements (REMA). Currently, electricity prices in the UK are determined by the cost of the most expensive generation source—usually gas—leading to high energy costs following Russia’s invasion of Ukraine.

“This system makes no sense. It drives up prices and impacts investment in renewables,” criticises Simkins. The government is considering reforming this structure to lower electricity costs, but uncertainty over the details of the reform leaves the sector in a state of limbo.

The Future of Solar Energy in the UK

Despite regulatory uncertainties and technical challenges, the UK solar sector continues to expand. However, to maintain its competitiveness against other European markets, the government must clarify capacity limits, streamline grid connections, and encourage investment in energy storage.

“The sector has enormous potential, but it needs clear rules and support to fully capitalise on its opportunities,” concludes Simkins. With the government-industry Solar Roadmap set to be published in spring 2025, the industry is eagerly awaiting answers that will shape its future.