Solar energy is very popular with politicians. A green argument is usually easily won and persuasive; after all, when did you last hear a politician denounce green policies?

When did you last watch an episode of ‘Grand Designs’ when the words ‘ecologically friendly’ and ‘sustainable’ were not used?

Trouble is, this solar energy lark is not all it’s cracked up to be. If you live in a typical UK house, your hot water energy bill is unlikely to account for more than 15%-20% of your gas (or oil) costs.

Therefore, although solar generated hot water works, and it can heat about 70% of your hot water requirements (in the winter months it is less effective in the UK) – providing you have a large enough cylinder and the panels are pointing the right way – in financial terms it is difficult to justify.

For instance, if your hot water bill was £150 per year, and solar cost £4000 to put in, it would take over 26 yrs before you broke even. This does not include any maintenance costs, depreciation and what you could have earnt on your money in the bank in the meantime.

Most solar systems would need replacement within this lifetime anyway, rendering the investment worthless.  This is ignoring the enviromental impact of making and installing them.

If solar energy could be directed towards space heating your house, it would make sound financial sense. Unfortunately, the physics don’t work in the UK.   We use space heating when the sun is out least, taking away the energy source.  Although systems do exist (eg: Sonnenkraft) they do not financially cost in against conventional heating systems because they need large buffer tanks, and underfloor heating.  They work better in countries with year round sunlight.

If you have a larger property, particularly one which is difficult to insulate, the Honeywell Hometronic energy management system will reduce wastage on the 80% portion of your energy bill directed at heating the house, and pay for itself in a much shorter timescale than solar.

All Honeywell need to do is make a version in a huge box strapped to domestic house roofs and politicians will start recommending it.