How cost effective is PV

misterfish

We're trying to do what we can to go green in a sensible way. All the light bulbs are low energy cfl where possible, cavity wall is insulated, loft has almost 300mm insulation, central heating has gas condensing boiler with heating zones with programmable thermostats as well as all radiators having thermostatic valves, we have a large well insulated mains pressure hot water tank with a solar array on the roof. Our electricity supplier is a 'green' hydroelectric company.

So we were wondering about solar PV. We've tried looking around and found that any grants available are small compared to most of the rest of the EU and North America and are really questioning the cost effectiveness of these systems. If we were to spend about £15,000 on a mains connected system (where we sell back excess generation to the 'grid') would we be taking a sensible step? Apart from the 'feel good' factor and the possibility of being less reliant on external supply would we do better to save the money (with currrent derisory rates of interest) or 'invest' it in a PV system. We've got a south-west facing roof and are on the south coast in sunny Chichester, West Sussex.

Any comments or suggestions would be appreciated.

Misterfish

Umski

hello Misterfish, your set-up sounds promising but I personally wouldn't spend that much on PV - I suspect you would not be making much excess to sell back to the grid without spending more than 15k. It depends how much you use and how much will be generated at the end of the day

cliffski

Do it. I polan to do it the minute I move. You have a south facing roof so your situation is ideal. consider this:

Payback time may be long now, but energy prices are certain to rise dramatically over the lifetime (>15 years) of your installation

The panels will raise the value of your home anywya, so much of the investment is in theory recoupable

The current savings interests rates are effectively negative, given inflation. This means the money earns mroe on your roof than in your bank.

You can afford it now. If your circumstances are less good in 5 years time, you will still be getting cheap or free electrivity (or even earning from the grid). This is like a business imnvestment. Why not insure yourself against future high energy prices?

I hope that helps. I'm very keen to get PV installed myself, but am waiting until an imminent house move so as to not go to all the trouble for a property I'll hardly lvie in to enjoy them.

Cardew

You might care to look at this page from the Energy Saving Trust.

http://www.energysavingtrust.org.uk/Generate-your-own-energy/Types-of-renewables/Solar-electricity

You might save up to £250 a year from your £15,000 PV array.

Even with the very low interest rates at present you can still get 3% on your money - with every prospect of rates rising in the future.

So that is £450 pa lost interest(compounded) to save £250(which will no doubt increase in future years)

You also will have to get on the roof to clean the grime and bird droppings or the output will drop off.

At the moment IMO it makes absolutely no economic sense.

However according to some reports there will be great strides forward in the technology in the years to come and if China get in on the manufacture in a big way it may become viable.

I was reading a report in the USA that they hope to produce 'thin film' PV at a cost of 1 US$ a Watt.