Is it worth installing solar panels?

If you’re asking about value for money, then the short answer is probably “no” – particularly if you are planning to move any time soon.
If that sounds a bit blunt, let me explain. Of course, it can be argued that anything which helps cut fuel bills will enhance the saleability of a home, and all other things being equal that may well be true. However, as with any other expensive home improvement, you will never recoup the full cost of a solar installation - as much as £20,000 for an electricity-generating photovoltaic (pv) system - when you sell.
But what if you are planning to stay put for a while? On solar water-heating, opinion is pretty evenly split between those who swear by it, and claim that their systems will pay for themselves within as little as 4 or 5 years, and those who claim the opposite. The Royal Institution of Chartered Surveyors, for example, published an energy efficiency report in 2008 which maintained that it could take anything up to 100 years to recoup the initial outlay – with systems which only have a useful lifespan of 30 years in the first place! Although this report caused a great deal of controversy, I think it’s only fair to say that the jury is therefore still out as far as the economics of solar water heating is concerned.
Meanwhile, when it comes to pv systems, the economic case seems to be much weaker - even allowing for the generous unit price your local power company will be obliged to pay for any daytime surplus electricity you generate. After all, pv technology may work well in places like Southern California or Arizona, where they average 9 hours sun every day, but here in rainy Britain it’s a very different story.
Of course, many people believe that the importance of doing your bit to save the planet far outweighs any considerations of value for money. If you’re one of them, and if you can afford it, then by all means install solar panels. At the very least, they’ll make you feel good.
But, if you main concern is to find ways to reduce your dependence on increasingly expensive bought-in energy, then you’ll find that things like decent loft insulation will probably achieve far more, at much lower cost.