Solar panels – are they worth it?

How much can you really save?

As well as saving you money on your energy bills, solar panels can also earn you cash. And don't worry, panels can still generate some electricity on gloomy days, vital when the weather's as dull as dishwater. But with solar panels costing an average of $6,866, there are a few things you need to understand to work out if the sums add up.

First and foremost, you can use the electricity your panels generate, and so reduce your bills. Savings depend on system size, electricity use, whether you're at home during the day to use the energy you're producing and other factors.

The biggest gain comes from using what you generate – you could save up to $580/year on your bills

But based on Energy Saving Trust estimates, a typical household with a 3.5 kilowatt-peak system can knock between $237 and $580 a year off bills at the current Energy Price Guarantee rates.

Not all homes are suitable for solar panels

To maximise what your panels can make, it's best to make sure your home is right for them:

• You usually need a predominantly south-facing roof. If your roof faces south-west or west you'll still get some benefit, but it may be less effective, and you might not get the maximum savings.

• Your roof should be unshaded between 10am and 4pm. While some early or late shading from other buildings or trees is OK, during the peak period for daylight you want the panels to be out of any shade.

• You need a fair bit of space. Solar panels typically take up two square metres each, so the size of your roof matters.

• Your roof needs to be in good condition. Make sure you've had an inspection carried out to ensure your roof isn't damaged, as this could affect the installation. If you have old tiles, it may be worth getting them replaced before your panels are installed.

• It's best to have a diagonal roof to catch the most rays. If you want to install panels on a flat roof it could cost more, as you may need fixings to hold the panels in place.

  
  

Solar batteries are expensive but may be worth it for those who use a substantial amount of electricity

A solar battery can store any excess power generated by your solar panels that you don't use at the time, rather than exporting it back to the grid. They can cost as little as £1,000 for a three kilowatt-hour battery. The Eco Experts estimate the average price to be around $5618.

The savings you make on your bills can be significant, though. The price you're paid for each unit of energy you export to the grid is usually much lower than the price you pay your supplier for electricity. So, economically, it makes more sense to store the energy and use it yourself – with E.on saying a household with a battery could use 30% more of the electricity they generate themselves.