As the days get longer and brighter, summer is a great time to think about how your building could make the most of the sun. For many village halls and community buildings, the roof space above them represents a valuable but often underused asset.

Solar photovoltaic (PV) panels can turn that space into a source of clean, renewable electricity – helping to reduce energy bills and futureproof against rising energy costs. Here are some key questions we get asked about solar PV and battery storage:

 

1. How does solar PV work and what is the benefit for community buildings?

Solar PV (photovoltaic) panels are made up of layers of materials that react when exposed to daylight. When sunlight hits the panels, it creates a flow of electricity – this is known as direct current (DC) electricity. Because buildings use a different type of electricity (alternating current, or AC), the system includes an inverter which converts the electricity from the panels into a form that can be used in your building.

Once converted, the electricity will be used automatically by anything that’s drawing electricity in the building at the time – such as lighting, fridges, kitchen equipment, or heating/cooling systems. If the panels are producing more electricity than the building needs at that moment, there are two options:

• The excess can be exported to the grid, usually via a smart export guarantee (SEG) rate, which are currently around 10-12p/kWh
• Or it can be stored in a battery for use within the building later

For community buildings, the key benefit is that once solar panels are installed, they will continue to generate free renewable energy for around 20-25 years. Reducing the amount you need to buy from your energy supplier and helping to lower costs and carbon emissions. When assessing buildings for solar PV we often see payback periods of between 6-10 years – which means after this time the panels have effectively paid for themselves in energy bill savings.

 

2. What makes a building suitable for solar PV?

While many community buildings can benefit from solar PV, the level of savings and performance will depend on how well the system matches the building’s characteristics and energy use. A good solar installation is about sizing the system well and having the right conditions to generate and use the electricity effectively. Here are three key factors to consider:

 

1. Roof orientation, pitch and shading

The direction your roof faces affects how much sunlight the panels receive over the course of the day. South-facing roofs usually provide the highest overall generation, however an east and west-facing roof can still work very well, often spreading generation more evenly across the day.

Most pitched roofs typically seen on community buildings are suitable without adjustment. The UK’s latitude means the sun is relatively low in the sky for much of the year, and a pitch of around 35° is thought to be ideal as it balances summer and winter performance. There are systems which allow solar panels to be added to flat roofs but fixing systems and additional weight loading on the roof structure will need to be considered.

Shading from trees, chimneys, or nearby buildings can reduce output – sometimes significantly if panels are shaded for long periods. Even partial shading can affect the performance of a system, so this needs to be assessed carefully as part of the system design process. If shading is unavoidable, microinverters can be installed on each individual solar panel, allowing them to operate independently so that if one panel is shaded or underperforming, it doesn’t reduce the output of the entire system.

 

2. Available roof space and layout

The size and layout of your roof will ultimately determine how many panels can be installed. Larger, uninterrupted areas allow for bigger systems and greater savings, whereas roofs with lots of obstacles (vents, skylights) may limit system size. Multiple roofs with different aspects can be used, but this may require a more tailored design and will likely come with slightly higher cost due to access requirements.

Before installing solar PV, it’s important to ensure the roof is in good condition and roof coverings should have adequate remaining lifespan (25 years +). It’s often more cost-effective to carry out any roof repairs before installing panels, rather than needing to remove and reinstall them later.

In general, more available space means more potential to generate electricity – but this should always be balanced against how much energy the building actually uses. We recommended aiming to size a solar PV system so that at least 50% of the energy generated is utilised on site. This maximises the return on investment and reduces the risk of changes to export tariffs.

 

3. Electricity usage patterns

One of the most important factors is how much electricity your building uses and when it uses that electricity. Solar PV generates electricity during the daytime, with a peak around midday, this means buildings with heavy electricity use during the day tend to benefit the most. If a building is mostly used in the evenings, solar can still be beneficial, but more electricity may be exported unless a battery is installed. You also need to consider how the building uses electricity across a year, solar PV generates the most energy over summer, when buildings tend to use less energy. During the winter this flips and energy usage tends to be higher and generation from solar PV is at its lowest. It is often the shoulder seasons, spring and autumn, where a community building will use the most energy from a solar PV system.

 

3. Is battery storage worth considering for community buildings?

Battery storage is often discussed alongside solar PV as a way to get more value from the electricity you generate. In simple terms, a battery allows you to store any excess solar electricity produced during the day and use it later – such as in the evening or other times when your building is in higher use. Without a battery, any electricity your building doesn’t use immediately is typically exported back to the grid. While this can provide some income, it is usually more beneficial to use as much of your solar generation on-site as possible, and this is where battery storage can help.

Most halls typically don’t require large battery systems – often around 10 kW is sufficient to support evening use, events, or basic load shifting. Larger systems are only likely to be justified where buildings have significant electrical demand, such as electric heating and cooling systems, or consistently high usage throughout the day and evening.

As with solar PV, the key is to size the battery appropriately to match actual demand, ensuring good value without over-investing in unnecessary capacity. While prices have been falling, it’s important to assess whether the additional investment will deliver good value over time. The biggest factor in deciding whether a battery is worthwhile is how and when your building uses electricity. Batteries can increase self-consumption, but the financial payback can vary depending on electricity usage, tariffs, and system design. In some cases, the benefits are more about flexibility and future-proofing than immediate cost savings.

 

4. Can battery storage be used to provide electricity during a power cut?

Battery storage systems can be designed to provide a level of backup power during a grid outage, acting as an emergency energy supply. In the event of a power cut, a battery system can continue to supply electricity to selected parts of the building – such as emergency lighting, fire alarms, fridges, or key equipment – helping community buildings remain operational and maintain essential services. This can improve resilience, particularly in buildings that serve as local hubs or are relied upon during emergencies.

Not all systems include this capability by default, and providing backup power requires specific design considerations, such as dedicated circuits, additional controls, and careful prioritisation of critical loads. It’s also important to recognise that batteries have limited capacity and are typically intended to support essential systems for a defined period, rather than act as a full replacement for a generator.

 

Case Study: Brampton Memorial Centre

Brampton Memorial Centre is a great example of how the right support can help turn an idea into a successful project. The trustees were already exploring solar PV and battery storage as a potential way to reduce energy costs. Through an FCCB energy audit and follow-up support, we were able to ensure the system they installed was the right size and suited to their building’s needs.

The result is a 19.8kWP solar PV system, along with 32kW battery storage. This system is expected to generate over 18,000 kWh of renewable electricity each year. Helping to significantly reduce running costs and improve the building’s long-term sustainability.

 

Next steps

If your community building is considering solar PV, or simply looking for ways to reduce energy costs, getting the right advice early on can make a big difference. We can support you to:

• Understand your building’s energy use
• Assess whether solar PV is suitable
• Identify the right size and type of system
• Develop a clear plan for improvements

 

Get in touch with Oli to find out more or to arrange an energy audit: oli.bachini@cambsacre.org.uk