If you’re considering solar panels for your home but feel as though your main roof isn’t suitable or large enough for solar, your garage could be the perfect solution. Installing solar panels on a garage roof not only makes use of otherwise unused space but can also help maximise your home’s energy production.
However, like any solar installation, there are several important factors to consider, from roof orientation and shading to structural support and electrical wiring. In this guide, we’ll explore the pros, cons, and key considerations of installing solar panels on a garage roof or outbuilding, helping you decide if it’s the right choice for your property.
Is Your Garage Roof Suitable for Solar Panels?
Installing solar panels on a garage roof is essentially the same as installing solar panels on any other building. Therefore, there are several considerations that should be undertaken before making the decision to go ahead with the installation, starting with the key question: “Is my roof suitable for solar panels?”.
1. Garage Roof size
The size of your garage roof will determine how large your solar PV system can be. On average, a UK garage measures around 5 metres by 3 metres, providing roughly 15 square metres of usable roof space. Which is enough to fit around 8 to 9 solar panels, depending on the output size, brand and model. This estimate is based on a typical 450W panel measuring approximately 1.7m x 1.1m, though the exact number may vary depending on your chosen panel.
2.Roof Orientation
For maximum exposure to sunlight in the UK, a south-facing roof is best. However, this doesn’t mean you should completely rule out all other orientations. The pitch of your roof should also be considered, an angle of 30° to 40° is typically best for capturing the most sunlight throughout the year.
3. Shading Factors
If the garage is attached to a house there may be shading issues depending on the orientation of the main building. Other potential sources of shade include nearby trees or chimneys. Shading on solar panels can significantly reduce your system’s performance, so ideally, your garage roof should have a clear, unobstructed view of the sky to maximise on solar generation.
4. Structural Strength
Solar panels can weigh between 20kg – 25kg and, while most garage roofs can support this added weight, if the garage is in poor condition it is best to seek the advice of a structural engineer, or to arrange an on-site survey.
5.Type of Roof
Installing solar panels to a pitched garage roof with concrete tiles is typically the most cost effective, compared to a flat roof or slate installation. This is because flat and slate installations are often more complex and require bespoke mounting equipment. Additionally, flat roofs usually accommodate fewer panels due to the spacing required to prevent shading between them.
For older garages, it is important to consider the construction materials used, as materials like asbestos are still commonly found. If you’re unsure, always seek professional advice before proceeding.
Solar Panels on Garage Pros and Cons?
- As most garages in the UK are single-storey, solar panels installed on garages are generally easier to access for cleaning and maintenance. This convenient access can also help reduce installation costs, as scaffolding may not be required.
- Installing solar panels on your garage allows you to turn an unused space into a source of clean energy for your home, while preserving the appearance of your main property. This could be an important consideration for listed buildings or homes in conservation areas.
- Garages provide a weather-tight and secure space to install your solar inverter and battery storage, safely separated from the main property. Installing solar panels on your garage also keeps your power source local to the rest of your solar equipment for improved efficiency and convenience.
- Garage roofs may experience shading from nearby trees or the main property, which can reduce the efficiency and energy output of a solar panel installation.
- Some garage roofs may need structural strengthening to safely support solar panels, which can add extra cost and complexity to the installation.
- Installing solar panels on a garage roof may involve extra wiring to connect the system to your main property. Depending on the location and distance, this could mean digging trenches to run cables discreetly. You may also need electrical upgrades, such as adding a sub distribution board in your garage, all of which can increase installation costs depending on your project details.
Types of Garage Roofs That Work Best for Solar
When it comes to installing solar panels on a garage, the type of roof you have can make a big difference in efficiency, cost, and ease of installation.
1. South-Facing Pitched Roofs
A south-facing pitched roof is the most ideal for solar panels in the UK, as it captures the most sunlight throughout the day, for maximum energy generation.
2. East–West Pitched Roofs
If your garage has an east–west orientation, solar panels can be installed across both sides of the roof, capturing the morning sun as well as the afternoon sun. This type array, ensures a steady energy production over the full course of the day.
3. Flat roofs
Flat Roof top garages also work best for solar panels, as installers can use angled mounting systems such as Van Der Valk or solar tubs to tilt the panels for optimal sunlight exposure. While this setup can be slightly more expensive due to the additional equipment required, it offers greater flexibility in positioning and performance.
To conclude, almost any type of garage roof, as long as it’s structurally sound and has minimal shading can support solar panels. A professional solar installer can assess your roof’s condition, orientation, and angle to design the most efficient setup for your property.
Do you need planning permission to install panels on your garage roof?
In the UK, solar panel installations fall under Permitted Development, so in most cases, you can proceed without any issues. As of 2024, flat roof solar installations are also included under permitted development rights, for which planning permission was previously required for.
Further investigation might be necessary if the garage or outbuilding is located in a Conservation Area, an Area of Outstanding Natural Beauty, is part of a listed building, or is subject to any covenants.
Can I heat and power my garage with solar panels?
Yes, with the right combination of panels, solar inverter and battery storage, you can both heat and power your garage with solar panels efficiently. Installing solar panels on a nearby garage or outbuilding is a great way to generate electricity to power lights, sockets, small appliances, and even heating. But first, there are a few key considerations:
Grid Connection:
If your garage doesn’t currently have a grid connection, it may be more cost-effective to design a system that operates completely off-grid. This involves pairing your solar panels with a sufficiently sized battery storage system and a Solar Gateway or Emergency Power Supply connection, allowing you to store excess energy for use when the sun isn’t shining or during a grid outage.
If your garage is connected to your property’s main electrical supply, a Grid-tied system can be installed, allowing you to use solar energy while still benefiting from the reliability and support of the main grid, as well as Smart Export Guarantee payments.
Heating:
If you are looking to heat your garage from solar energy, then electric heaters or even a heat pump will be the best solution. Keep in mind that heating can be energy-intensive, so your solar panel system will need to be sized appropriately to meet your heating demands.
System sizing:
The size of your garage and your energy needs will determine the number of solar panels and the capacity of your battery storage required to adequately heat and power your garage with solar energy.
Cost of Installing Solar Panels on a Garage Roof
The cost of installing solar panels on a garage roof can vary depending on several factors, including the size of the system, type of roof, installation complexity, whether your garage is attached or detached from your main property, and if it has a grid connection.
On average, you can expect to pay between £1,200 – £1,800 per kW for a standard solar panel installation in the UK. For a typical garage roof that can accommodate 8 to 10 solar panels, the total cost usually ranges from £4,000 to £7,000. Of course, the final installation price may be higher if your installation requires:
- Additional wiring or trenching to connect the garage to your main property
- Specialist mounting systems (particularly for a flat or slate roof solar installation)
- Roof reinforcement or structural upgrades
- If you are looking to invest in a solar battery also.
Despite the upfront cost of installing solar panels on your garage roof or outbuilding, it can deliver long-term savings, helping you to save on your energy bills, boost your property’s value and energy independence, whilst reducing your carbon footprint. It can also in some cases be a more cost-effective solution, as the installation is unlikely to require scaffolding.
If you’re a UK homeowner or business owner looking for an accurate price to install solar panels on a garage roof, it’s best to request a free solar survey from a certified installer like Deege Solar. Our team can assess your garage roof, evaluate your energy needs, and provide a tailored quote based on your property and potential savings.
Can You Power Your Home from Garage Roof Solar Panels?
Yes, you can power your home with solar panels installed on your garage roof. If your garage is wired to your main electrical supply, the solar panels can feed energy directly into your home’s system, helping to power your appliances, lighting, and even charge an EV.
