Solar panels are becoming an increasingly popular way for homeowners to enjoy lower energy bills – but make sure you choose the right ones. Find out more in this solar panel guide.
There are two kinds of solar panels. Solar thermal panels take energy from the sun and use it to heat water, which can then be used within the home as heating, or in baths, showers, washing machines or dishwashers. These panels can cut your heating bills, and reduce your carbon emissions, so they can be very useful.
However, if you’re hoping to earn money from your solar panels, the ones you want are photovoltaic (PV) solar panels. They create electricity that you can use in real time to power appliances and light your home. You can then earn money by selling any surplus back to the national grid.
You may get phone calls from agents encouraging you to install solar panels. So if you’re hoping to earn money from them, make sure you sign up for solar PV panels rather than the thermal variety.
Solar PV panels are made up of lots of solar cells that convert sunlight into electricity, which is then fed into the building on which the panel is installed.
Each solar cell contains two wafer-thin layers of silicon crystal on top of one another. The top layer has been treated so that its atoms are unstable and it has too many electrons, while the bottom layer has also been treated, but this time has too few electrons. The electrons want to move from the top layer to the bottom, but they can’t until the cells are exposed to sunlight.
When light hits the top layer the electrons become ‘excited’ and start to move to the bottom layer, and once electrons move together in the same direction, electricity is created. Two metal contacts are placed on either side of the silicon layers to create a circuit.
Electricity generated by solar panels is direct current (DC), whereas the electricity used in buildings is alternating current (AC), so the electricity has to run through an inverter before it can be fed into the building.
PV cells work even when it’s cloudy, although they generate more electricity on sunny days. And the more hours of sunlight you get, the longer they work each day, so you get more solar panel output in the summer even if it’s not a particularly hot one.
Home solar panel systems usually range from 1kW up to 5kW in size. If they’re working at peak efficiency, this is how much energy they could produce:
|Size of installation||Amount of energy produced each year|
|1 kW||850 kW units|
|2 kW||1,700 kW units|
|5 kW||4,500 kW units|
According to the Energy Saving Trust, the average domestic solar PV installation costs between £6,000 and £9,000 (including VAT). Various factors can affect the price, such as the size of the installation, whether you choose tiles or panels, and whether it’s built into the roof or sits on top of the roof. Larger systems are usually more cost-effective than smaller systems.
You should also allow for other possible costs:
The good news is that solar panels cost very little to run, and should keep going for at least 25 years. Your installer should give you a checklist of any maintenance you might to need to carry out, but it will be minimal. Really, you just need to keep an eye on the panels to make sure they’re clean – and in the UK, as long as they’re installed at an angle of 15% or more, the rain should wash them for you.
You should also be aware of any trees growing or planted near your home, because as they grow taller they may start to shade your panels from the sun.
Yes. Solar energy is renewable, so it doesn’t add to our planet’s load of harmful carbon dioxide or other pollutants. In fact, an average installation of solar PV panels could save more than 1½ tonnes of carbon dioxide each year, adding up to 30 tonnes over 20 years.
Solar panels generate energy for use in your home that would otherwise be provided by an electricity supplier, so the energy created is technically ‘free’. According to the Energy Saving Trust, an average-sized system will generate enough electricity to cover a typical household’s energy needs every year, so you could enjoy greatly reduced energy bills.
There are some initial costs involved, but it’s also possible to earn money from solar panels by selling electricity back to the grid and from the government’s renewable energy initiatives. A solar panel installation can typically pay for itself within 12-20 years.
The current way of earning money from solar panels is through the Feed-in Tariff (FiT).
If you want to generate as much electricity as possible, it’s best if you’ve got a south-facing roof at an angle of about 30°. PV panels will still work if your roof faces east or west, and even north, although of course they’ll get less sun. They can even be installed on flat roofs, using a frame to tilt them to a suitable angle.
The larger the installation, the more effective it is, so it’s best to find the largest possible site for it. So even if you’ve got a south-facing extension while your main roof faces west, it will be more effective to place the panels on your main roof area.