While the adoption of C&I rooftop solar is growing rapidly, research suggests that assets are often not operated at their full potential. Here, Peter Hall, director of asset management at AMPYR Distributed Energy (ADE), explains the importance of lifecycle maintenance, explores the pitfalls of failing to plan for the future, and discusses who is ultimately responsible for solar optimisation.

Rooftop solar delivers significant benefits from an energy cost and carbon saving perspective, so it’s no surprise that adoption figures are growing rapidly. Provisionally, Government figures show that (as of the end of June 2025) there was 19.0 GW of solar capacity in the UK across two million installations. This is an increase of 7.8% (1.4 GW) since June 2024.

While it’s safe to say that the bulk of new arrays are domestic, they only account for 30% of capacity, with the remainder – which is rising rapidly – split between ground-mount and rooftop solar on non-residential buildings. This is positive news for the UK government, which is targeting 45-47GW of installed solar capacity by 2030 through its Clean Power Action Plan and Solar Roadmap.

Soaring energy bills, new regulations and corporate ESG commitments, along with innovative funding models and the removal of planning barriers, have further boosted adoption on commercial buildings and warehouses. The attraction of solar is its ability to reduce energy costs, cut carbon emissions and increase energy resilience by cutting reliance on grid supplies that are subject to volatile prices and capacity constraints.

However, some of these benefits can be lost if long-term planning for the lifespan of the asset is not addressed before they are deployed.

At ADE, we regularly see the consequences of poor maintenance, with organisations disenfranchised with the performance of their solar panels and struggling to remedy the situation. From schools and hospitals to a wide range of commercial businesses, many systems are affected by issues that reduce their performance or stop them from working altogether.

A 2023 scientific study analysed 3.3 million solar PV modules across the UK using thermographic and electroluminescent inspections and found that 36.5% of modules had thermal defects, including approximately 900,000 modules with single or multiple hotspots and around 250,000 with heated substrings. These defects are linked to output degradation over time. Sites with a higher proportion of defective panels showed increased rates of annual reduction in energy output, highlighting the importance of ongoing inspection and maintenance for longevity and performance.

Another large-scale UK study identified that ‘hot spots’, i.e. areas of increased temperature that can cause accelerated ageing and permanent performance loss, are prevalent in certain regions, particularly the North of England. This means that, without regular diagnostics and maintenance, a significant fraction of installed capacity could underperform or cease to work long before its expected lifespan.

The reality is that solar panels are not a fit and forget option. Ongoing maintenance must be a consideration from the outset. Without active monitoring and inspections, solar panels can become cracked or broken, while generation meters and electrical connections might fail and system outputs can decline sharply due to issues that often go undetected.

The reason that solar panels are failing now, on both commercial and public sector buildings is down to a number of factors. Reasons that some panels are left unattended and become nonproductive can include a lack of knowledge and awareness of who is responsible for maintenance and what good looks like, concerns about the costs and uncertainty about the implications for budgets if faults are identified. We know that some schools and businesses, for example, sourced panels under the old Feed in Tariffs (FiTs) regime and own the assets outright but didn’t plan for monitoring and optimising their use over the next 10 to 20 years. Now these units are failing due to neglect, and replacement rather than repair is the only solution.

If the building owner also owns the solar PV system, they are personally responsible for delivering O&M. When it comes to rented buildings, the responsibility for solar PV maintenance depends on the tenancy agreement.

Developers are only responsible for the system during the build and initial handover phase. After commissioning, responsibility typically transfers to the property owner or long-term operator, unless an ongoing service contract is in place.

However, where a system is financed via a power purchase agreement (PPA) then ongoing maintenance is part of the deal. After all, the PPA’s effectiveness for both parties relies on the system performing well throughout its lifespan.

As a leading provider of PPA funding for commercial rooftop solar, maintenance is embedded into ADE’s installations from day one and will happen seamlessly over the lifetime of the panels at no extra cost. To ensure optimal performance from start to finish, we manage contractors (for preventative maintenance and response to issues), harness AI to analyse performance in real time, manage spare parts holdings to ensure rapid replacement, and provide a dedicated portal for customers.

We pride ourselves on these seamless solutions, intricate monitoring capabilities and preventative maintenance work – it’s just another way that we reduce barriers to net zero for C&I customers across the UK and Europe.

Today, there is a greater understanding of the need for future commercial and public sector rooftop solar installations to come with professional lifetime maintenance contracts. With access to PPAs, there is no upfront cost for either the panels or the maintenance contract and the ongoing cost for energy can still be reduced by as much as 40% as optimal performance is sustained for the long-term.

What’s more, businesses benefit from full insurance and a dedicated asset management point of contact for the resolution of issues and queries. That’s a win for the bottom line and the environment.