Solar Electric

Solar panels are one of the easiest ways to generate your own electricity. Buy as many panels as you can afford and will fit onto your roof, but be wary of shade and orientation.

Summary

Harnessing the sun to generate electricity is one of the easiest things that can be done by homeowners. Installing panels onto a roof by one of the many installers, using the electricity and exporting surplus to the grid is attractive. Added to this is the Feed In Tariff (FIT) available for most homeowners, which can give a return on your capital within 7 or so years.

The solar panel industry is now mature and panels are expected to last well over 25 years with only marginal lessening of output. As the government has reduced the Feed In Tariff (FIT), the costs of installing solar panels has reduced too.

The panels use the sun’s energy to move electrons in the panels creating an electric current. Put a whole lot of these cells into a panel and a respectable amount of electricity is generated when the sun shines – and less when it is merely daylight. The electricity goes into a box called an inverter that turns it into regular 240 volt mains electricity. It is then available for your use or, if you are not using it, fed back into the national grid. The finances of buying electricity at perhaps 15 pence a unit and selling it at 4 pence means it’s much better for you to use it if you can by planning to put on devices during the day. CSE have put together an excellent guide on how to get the most out of your solar panels.

A generation meter tells you how much you have created (on which FIT is based) and an import export meter determines how much has gone to the grid.

Your panels can be in a variety of places ranging from the bottom of the garden to outbuildings. Ideally, panels should be at an angle of around 35 degrees, facing south. There are plenty of panels facing west and east or even flat: it’s just that the output is reduced somewhat. A flat panel will generate around 87% and a west facing panel at 35 degrees will generate 81% of the maximum.

For a domestic installation of 2 kW, it may cost you around £6-7,000 with returns depending upon how well placed it is. The FIT will give you 14 pence for each unit generated (though it changes every 6 months) and the 50% you are deemed to export earns you an extra 4.7 pence (at 2014-15 prices).

Installers need to be accredited as members of the Microgeneration Certification Scheme (MCS) and you will need to acquire an Energy Performance Certificate (EPC) for the house. If it’s not above a D, then you will earn less FIT meaning that you should look to address some of the other issues identified before installing if you can.

If you use plenty of hot water and don’t have room for solar hot water (a different solar technology), then you can buy a microgen heating device. This uses the spare electricity being generated to heat your water rather than importing electricity from the grid or using your gas boiler.

Your roofs will need to be strong enough to take something as heavy as a panel: they are mounted on gals (and thus fairly indestructible and self-cleaning) but they do weigh as much as a dump of snow. And then you may still get snow: a modern pitched roof will have plenty of strength: check with your installer if in doubt.

Geek says

  • Because a significant fraction of the cost is installation and control equipment, buy as many panels as you can afford and will fit onto your roof. It will repay more quickly.
  • Don’t be scared of installing on several roofs or mixing different orientations of roof.
  • Do be scared of trees or shading! Panels work in series, so shading of one part affects them all. Make sure the impact is factored into your calculations: your installer will help.
  • Don’t wait until next year when the panels will be cheaper/more efficient. The FIT will be less!

Local experiences

Judith, Oxford: Following discussions at LCON low carbon living, I got a couple of quotes that I was happy with and chose the Renewable Energy Co-operative (R-Eco) because they are a cooperative, which I liked. Based in Cornwall, they have an office and people who work for them in Oxford as well as some who travel. They were always on time, able to solve problems and make good recommendations for how to do the work.  This was a major investment for me and I’m really happy that I did it and confident that R-ECO would deliver on any follow-up.

Useful links

http://www.energysavingtrust.org.uk/domestic/content/solar-panels

http://www.cse.org.uk/advice/renewable-energy/solar-pv

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