Going solar harder than it needs to be

A standard panel is 1.7m2 and you can estimate the production of each panel for any given set of co-ordinates anywhere in the world.

For us, the calculation gives a nominal average output of .285 kW for a medium-range modern panel installed on our roof.

That’s less than 18m2 of panels for a 3kW system – much less than the 25m2 the government quotes.

Government figures are based on an “average” set of co-ordinates for France, and the difference in both costs and potential output is significant if you live anywhere sunnier than the average.

Also, for a recent 3kW “self-consumption” system the Foords should be getting more than 6 c/kWh sold to EDF.

If their contract falls in line with 2017/2018 legislation, they should get 10c/kWh for a 3kW system. The rate falls to 6c/kWh if a system is 9kW or more.

We have a south-facing roof capable of taking up to 18kW, so for us the economic case should be a no-brainer as panels are lighter and cheaper than clay tiles.

If the government was serious about renewables, we have more south-facing roof that could be turned over to production – potentially 36kW, which would be enough for us and all our immediate neighbours when the sun shines.

EDF told us they would not supply a system of more than 8.5kW and ideally wanted to supply no more than 4.0kW.

For “the privilege”, they wanted to charge a mark-up of around 60% over retail costings for materials and roofing work, with VAT at 20% factored into the retail costs.

The price they wanted for readily available LG panels was obscene. But there IS a strong case for solar panels in the sunnier parts of France, even given the current poor rates of “prime” and “buy back”, and we have to start to take reduction of carbon footprints seriously.

It’s going to take more than sorting our rubbish for recycling to reverse current trends.

France has the potential to be much greener than it is. I think it’s time to think differently about energy production.

Solar is not the best in terms of carbon footprint, and the supply is unstable, but it is better than wind farms and much better than gas.

It’s time for France to be brave about exploiting the solar potential of a warm and sunny country.

Martin Styles, Charente-Maritime

Your feature on solar energy confirmed our experience.

Last summer we were determined to install a solar power system to stop wasting our many hours of sunshine.

We expected to fork out a lot of cash but with the consolation of selling any unused power back to the grid.

We spoke to lots of installers – all small-scale and self-employed. All offered systems that didn’t even connect to the grid.

We would effectively be paying a five-figure sum to run our fridge and washing machine for free during daylight hours.

It didn’t make any sense – so we gave up. We keep hearing about risks to future energy security and threats posed to the planet by dirty energy (not to mention the expected soaring demand as electric car sales inevitably boom).

Yet we are actively discouraged from making use of free, clean energy that could supply all our needs. It is madness.

Nick and Fiona Jenkins, Dordogne