Fracking Hell...

I don't know what the efficiency is, but if the estimated payback for energy used to make vs energy saved is 2-8 years, even if the efficiency is half the assumed level it comes out ahead since panels must have a life span of 20-25 years?

But that means that after 2-8 years you've broken even, only in year (averaging) 6 onward do you start to make energy.

And if the efficiency level is half the projected level, because you are in, for example, Wales, then that's 12 years before you start to see a return.

So you make hay in years 13-20, just as long as other generation techniques have not come along by then, and also just as long as your panels efficiency has not dropped to 5% over the years.

In a strange way the panel could be seen as a kind of battery- we use a gas powered plant to make a panel that then pays back a fraction of that energy over a period of 20 years.