Integrated solar panel solution - low carbon heating in social housing

The UK’s net zero strategy includes ambitious carbon reduction targets in both the updated Approved Document L and the upcoming Future Homes Standard. With spiralling energy costs, increasing concern for the environment and the poor energy performance of much of the existing housing stock, the spotlight is on those responsible for improving energy performance, particularly in social housing. And integrated solar panels can help to achieve compliance, discusses Stuart Nicholson, roof systems director at Marley.

“Targets are clear. All new homes are expected to produce 31% lower carbon emissions as part of the updated Approved Document L.”

Playing a significant role in delivering a more sustainable future will be the decisions of local authorities and social housing providers who must incorporate energy-saving technologies, such as solar panels and heat pumps, into new properties and refurbishment projects. The current energy cost crisis, and the uncertainty that goes with it, also emphasises the urgent need to provide vulnerable tenants with access to cheaper heat and power.

The current and future roles of solar panels

While the new requirements of Approved Document L and the upcoming Future Homes Standard seem to put an emphasis on the conservation of power, particularly U-values, improvements in energy efficiency cannot purely be made through simple changes to the building fabric. It also requires a step change in the specification of available technology.

For local authorities and social housing providers, a clear specification pathway can assist in the urgent energy transformation of the homes they are responsible for.

“Rooftop PV solar panels, combined with an efficient gas boiler appear to be one of the easiest and most cost-effective ways to meet the new Part L targets. This is partly because supply chains are ready and trusted installers are in place,” explains Stuart. “PV technology is tried and tested. It’s readily available and has become much more affordable in recent years,” Stuart adds.

Looking into the future, under the Future Homes Standard, it is anticipated all new homes will have heat pumps as the primary heating system. “Heat pumps are one of the most efficient ways to provide space heating and domestic hot water. But they still require electricity to run – solar panels and heat pumps can work together to cut a home’s CO2 footprint and energy costs.” Stuart explains.

Solar panels as part of the low-carbon energy mix

“We’re already beginning to see the diverse range of technologies that will be installed to achieve compliance and bring down energy costs. The role of solar panels in this low-carbon energy mix is significant.” says Stuart. The trend for solar panel installations has been upward for many years and according to the Microgeneration Certification Scheme (MCS), the number of installations in 2022 was double that of 2021.

But even with these impressive solar panel statistics, there is plenty of opportunity for improvement. “Around 1.2 million homes in the UK have solar panels. That’s only 4.1% of homes getting free energy from the sun. Imagine the environmental benefits if that number was much higher. Not to mention the financial benefits for social housing tenants,” he says.

Alongside popularity, factors such as improved aesthetics, affordability, quick installation times and proven performance are also helping to make the case for solar PV as a strategically important element of the home energy efficiency revolution.

Depending on available roof space and household electricity usage, a well-sized solar panel system can cover a significant portion of a home or building’s annual electricity usage – up to 65–75% in many cases. When used in combination with battery storage, solar PV also enhances energy cost efficiencies. By storing excess solar energy from the PV system for night-time usage, it can help tenants make savings on electricity bills.

Another way to get the best savings from a solar panel system is the use of power diverters. They use the surplus solar energy that the solar panels generate and, instead of letting it go back to the grid, redirect it. For example, to heat a household’s hot water tank cost-effectively.

Finally, when it comes to providing the most effective use of solar PV and heat pumps post 2025 when gas-fired boilers will be excluded from new builds, it is critical that properties are insulated to a high standard. If they are not, this will increase the heat demand within the home, leading to increased electricity pressures to generate heat. The more heat or warmth preserved by the property’s insulation, the greater the reduction of the running cost of heat pumps as they work less intensively.

Solar panels: aesthetics and performance

Advances in solar PV technology mean there are now many more design-led options available, and at much more affordable prices, which can better suit local authority and social housing budgets.

When it comes to solar PV, there are three options to choose from: a traditional on-roof panel, or two different types of integrated solar panel systems (one with a separate tray and one with an integrated tray).

Stuart explains the options available: “Many people associate solar panels with the original on-roof systems, which consist of a set of panels attached to the rafters using a mount, sitting over the top of the roof tiles. The problem is, these stand out too much, leaving space for debris to pile up or animals to start building homes. They also don’t offer the streamlined aesthetics that most developers desire.”

“Modern, integrated solar panels, such as the Marley SolarTile®, have been developed to blend in seamlessly with roofscapes. Roof-integrated solar panels are part of the roof surface, acting as an MCS 012 approved building material, effectively replacing a section of tiles.”

There is a belief that on-roof systems generate more electricity. However, the difference is relatively small and is outweighed by some of the other disadvantages of an on-roof system, particularly because they can look quite bulky.

Modern on-roof panels are sleeker than in the past, but they hold no comparison to the aesthetic of roof-integrated PV. Stuart adds: “As roof coverings and integrated solar panels are installed together, it means there is no modification to the roof tiles, thereby securing the warranty. Marley’s SolarTile® system is compatible with our clay and concrete tiles, allowing the easy incorporation of solar PV into any roof design.”

Solar panels and renewables funding: a catalyst for change

The UK government has announced a variety of schemes to provide funding to social landlords, including housing associations to carry out energy efficiency upgrades, such as the installation of solar panels. The first round of the Social Housing Decarbonisation Fund (SHDF) resulted in £179m being offered to 69 projects.

“Funding through the SHDF was intended to boost the energy efficiency of the existing social housing stock, particularly buildings with Energy Performance Certificate ratings below C. It also supported around 9,000 jobs in the green energy sector,” Stuart explains.

The deadline for the second round of SHDF funding, which will allocate up to £800m for social housing projects, has passed. “We hope that more funding programmes will be made available in the future,” Stuart says. “Renewables funding is critical for improving the energy efficiency of social housing stock and, therefore, the lives of the people who call these properties home.”

Specifying solar panels

While the targets might be clear, the path to compliance can be less obvious. With so many products and technologies available to local authorities and social housing providers, it’s easy to get overwhelmed with choices. “The good news,” says Stuart, “is there’s also a lot of help available to make the specification process easier. You just need to know where to look.”

Here at Marley, for instance, we have produced a variety of support materials and tools, from CPD presentations to BIM models, our online solar configurator tool and a collection of blog posts to answer common questions. And our expert team is available to discuss your project requirements in more detail, so please don’t hesitate to get in touch.