My Smart Energy experience started with an invitation to have a salesman visit me to show me their wonderful solar water heating system. I took them up on it, because I like the idea of sustainable energy sources. The salesman duly turned up and gave me the usual pitch - discount applicable only if you sign up today, you can earn money back by recommending friends or talking to potential customers, and so on: nothing new there. As part of his presentation he claimed that the system would pay for itself in seven to eight years, a ludicrous statement disproved in about thirty seconds' work using his own figures and a calculator. However I was already convinced that solar energy was the way to go and my other half was even keener. So we signed up.

Before we could have the system installed we needed some work done in the attic - this was something we were doing anyway so the installation provided a bit of an incentive to get on with it! Because of this, having purchased the system in May the year before last, we didn't actually get it until August the same year. My partner stayed at home waiting for the workmen, two of whom arrived on time, rapidly and professionally erected their scaffolding, put the collectors in place on the roof, installed the tank and associated plumbing, cleared up and went away again. Then we had to wait for someone else to connect it all up and make it work. And wait. And wait through three missed appointments. The connector-upper managed to keep the fourth appointment, about three weeks after we first expected him, and two days later the system was all connected and working.

As I said, it was then the end of August and the sun was shining. By the time I got up in the morning there was more than enough hot water for me to have a bath, should I so wish. The collectors use UV light and on a sunny summer day we literally have more hot water than we know what to do with. On a cloudy day the water is cooler and on the more miserable winter days the system raises the water temperature to barely lukewarm and we need to use the immersion heater. Still, heating water from lukewarm to hot is faster and cheaper than heating it from cold. You can, of course, use a timer to switch the immersion heater on to give you hot water in the morning. But I am writing this at the end of April, and by the time I wanted hot water at 8am today, the tank was up to 59 degrees - too hot to comfortably hold your hand under.

Eighteen months on, our system has worked wonderfully with two exceptions, neither of which were serious problems. A a few months ago, when we finally got the ceiling in the attic up, the temperatures in the collectors were getting high but the heat was not being transferred to the water. The pressure in the collectors had fallen, but my partner found how to adjust it by reading the manual Smart Energy give you when they install the system - one small tweak of a lever and everything was fine again.

The switch for the pump is located where it could easily be mistaken for a light switch. I assume that our builder mistakenly pressed a button he shouldn't have on the way down from the attic, but am not sure that's what happened. It might be an idea to fit a cover so nobody accidentally "fiddles"!