Well, that's difficult to say!

Solar water heaters are very efficient solar panels - around 85-90% efficient - and are mostly used for applications such as domestic hot water and heating swimming pools. These are very common in places such as Israel. Hawaii have even made them law!

Installation costs can be quite high but if you know some basic DIY you can install these solar panels yourself without too many problems.

Solar water heaters are far more efficient than PV solar panels. A typical solar power system can generate all the hot water needed in the summer and 20% in the winter, so 50%-60% all year round.

Find out about DIY solar heating kits here.

PV Solar Panels, which produce electricity, are a touch more expensive due to the lack of silicon supplies worldwide that are used to make them. However, with new technologies evolving constantly, the price is dropping rapidly for this type of solar panels.

There are also large rebates available in most countries for solar pv making it affordable to the ordinary family. Because of this, the growth has been rapid in many countries, especially in places like Germany where they have a feed in tariff.

You could even fit it yourself making it cheaper still. You wouldn't be eligible for a grant but the savings you would make would mean that it wouldn't matter. For more details click here.

But whatever you do, please shop around for the best price. Costs can vary dramatically and some dealers are complete rip off merchants so do your own research and bargain with them.