Solar panels will knock just £70 off the average household’s annual electricity bill, according to the Energy Saving Trust, rather than the previously stated £120.
The Energy Saving Trust (EST) had previously estimated that solar photovoltaic (PV) panels could cut electricity bills by 50%, but it now predicts that the average home will save just 25%.
Which? energy expert Sylvia Baron says: ‘It’s important to remember that if you are installing solar panels you will not only be saving this money on your energy bills – you can also make around £1,000 a year through the government’s feed-in tariff (FIT).
‘However, if your panels are installed for free through a ‘rent-a-roof’ scheme you won’t benefit from this additional income.’
Solar rent-a-roof schemes
These companies install solar panels on your roof for free and provide you with free electricity produced by the system. In exchange, they claim the income from the FIT.
Sylvia says: ‘With the new estimate suggesting that solar panels will save the average household just £70 on their electricity bills, many people will be questioning whether this saving is worth the hassle of having ‘free’ panels installed. Although it’s worth noting that if electricity prices rise, these savings figures will also rise.’
Maximise solar savings
According to the EST, £70 is a typical figure and households could save more money if change their behaviour.
EST data services manager Rosalyn Foreman said: ‘We followed trials of other technologies which you’d expect to export much less back to the grid than solar panels, but they showed lower levels of electricity used on site than expected, so we’ve altered our expectations of solar PV accordingly.
‘While these are typical estimates, it’s quite possible that someone could save more than £70 if they were at home in the day or set all their appliances to run in daylight hours.’
You can find more top tips on reducing your electricity bills – and see the difference that buying energy-efficient appliances can make – in our guide on how to use less electricity.
Solar panel investigation
Earlier this year Which? investigated solar PV companies – inviting 12 solar firms to a house rigged with secret cameras to see whether they were complying with the consumer code they signed up to.
We uncovered a range of issues, from salespeople using pressure-selling tactics and neglecting to mention ongoing costs, to many companies underestimating the time it would take for the panels to pay for themselves.
Lower your gas and electricity bills
You can compare energy prices and switch to a new gas and electricity supplier on Which? Switch. People who switched with us between 1 October and 31 December 2013 are predicted to save an average of £234 a year on their bills.
Which? RSS and Twitter news feeds
For daily consumer news, subscribe to the Which? consumer news RSS feed. If you have an older web browser you may need to copy and paste http://www.which.co.uk/feeds/news.xml into your newsreader.
Follow @WhichNews on Twitter for the latest news, or @WhichAction to see how we’re campaigning for consumers.