Four reasons why solar panels won’t work on your home

Within the next 30 years the Government envisions a future in which Britain produces net zero carbon emissions. Key to this strategy is more widespread adoption of renewable energy sources – and, for households, one of the easiest ways to get the ball rolling is to install solar panels.

The oft-touted reason for doing so is that the green technology will slash your bills, in one way or another. But whether you’ll be able to install them, and whether they will work as intended, is not as simple as net zero champions will have you believe.

Here, Telegraph Money outlines a few of the common reasons why solar panels might not work for your home.

Solar panels might not fit your roof

Britain’s housing stock is varied and full of character, and while most roof materials can support solar panels without issue, some can prove pretty tricky. One of the most common types of roof material in the UK, asphalt shingles, is ideal for panel installation, as are roofs made of metal, tar and gravel.

Tiled roofs are compatible with solar panels, but the installation process can be costly and complex. This is because tiles made from clay are typically more brittle and cannot be drilled through – meaning installers must instead remove them and secure brackets to the roof, before then replacing the tiles.

There’s also the problem that your roof may not be big enough to accommodate enough solar panels for it to be worth it. A 4kW installation, typical for a 2-3-person household, would require a surface area of 25.6 square metres. Given the average roof size in the UK is 65-75 square metres, this might not sound like much of an issue, but it can be complicated if you have features like roof windows to work around.

Your energy bills might not be much cheaper

The primary selling point of solar panels is that they can meet most of your home’s electricity needs without relying on the grid. An average household can save as much as 62pc per year on their electricity bills using solar panels alone, according to the Energy Savings Trust, a charity.

However, savings vary depending on when you are home using electricity, and for how long. Calculations by the EST found a typical house would save £610 a year using solar panels if its occupants were home all day – if they were working from home, for instance. That figure drops to £360 a year if a household is out all day until 6pm.

Households can also sell the electricity they generate back to the grid to cut their energy bills. The catch is that you’re not paid for your electricity at anywhere near the rate you pay for it yourself. 

Under the Smart Export Guarantee, power can be exported back to the grid at a rate of 3.5p per kWh – far less than the 33.2p you pay for electricity under the Energy Price Guarantee.

This can be mitigated with a solar battery, which means you can store surplus power and use it to power your home at other times. However, home batteries can be expensive, ranging between £1,200 and £6,000.

Solar panels don’t always work

Naturally, if your roof does not face the sun, solar panels will be a bad idea. South-facing roofs are ideal for maximising solar panel output, but they’re not recommended for those with north-facing roofs.

East- and west-facing panels fare better, although they still generate up to 20pc less electricity than a south-facing system, according to comparison site Green Match.

If your home is shaded – for instance, if it’s surrounded by tall buildings or trees – the efficiency of solar panels will also be reduced. 

This is because solar panel systems are wired in a series of parallel “strings”, which means that the output is based on the weakest panel in the set. No matter how many cells there are in a string, just one being in the shade can cause the output of the system to fall to zero, according to Deege Solar, a comparison site.

You’ll need a suitable space for an inverter

Energy specialist Evergreen Energy recommends making sure there is a small amount of room available in your attic for an inverter, a device that’s necessary to convert the current generated by the panels to the current used by the grid.

Inverters are usually fairly small, and can be attached to a wall – a little like a gas meter. You’ll need to have a spot placed away from direct sunlight with proper air ventilation, meaning a loft, garage, or utility room. 

It also needs to be easily accessible for routine check-ups and maintenance, and ideally have 3ft of water level clearance.