SIR – The T&A reports on the British Gas ‘Green Streets’ initiative, encouraging the installation of solar panels (Calls to switch to solar energy, September 11).

Installing solar panels is a good investment because while the average cost is between £10,000 and £15,000, anyone installing them receives two immediate benefits: 1. You will get free electricity during the hours of sunlight. Ideally, the system works best on south-facing pitched roofs, but it doesn’t need direct sunlight. It works on overcast or even rainy days.

2. Under the feed-in tariff (FIT), you are paid 41.3p per kilowatt/hour for all electricity generated, including that used by you, during the hours of daylight. This is guaranteed for the next 25 years.

British Gas is promoting a scheme called “rent a roof”, which means that they install the solar panels for free, but then they pocket the FIT income (you could still save about £500 a year from your free electricity used).

Over the quarter-century of the FIT scheme, British Gas will make a profit of well over 100 per cent – a nice little earner, indeed.

Far better to take out a mortgage to finance the purchase because the FIT income will offset the interest charges.

Karl Dallas, Church Green, Bradford