We have now mostly low energy light bulbs, with LEDs in most cases. LED (light-emitting diode) lights come on very quickly, unlike other low energy bulbs.
Over 10 years ago we had solar PV panels installed, to generate electricity. It was estimated that we would get our money back in about 10 years, because the government pays as a feed in tariff (FIT) for each unit of electricity we generate. Any electricity we cannot use while it is being generated is fed back into the electricity grid. Any electricity that we can use ourselves is free to us, whereas we have to pay for it at other times. We are paid for the electricity we generate but at a much lower price than we have to pay to buy it at other times. Now we try to use appliances such as the washing machine in the late morning when we generate the most electricity. Without the FIT it would be a long time before we would get back what we had spent on the panels.
We originally had 2 sets of 8 panels and, if any panel of the 8 was shaded, all the others also generated less electricity. That doesn't happen with optimisers, which weren't available when we started. Unfortunately we later had to have repairs done to the chimney, which was expensive, but it gave us the chance to increase the electricity generated by fitting optimisers. While scaffolding was up there, we had an optimiser fitted to each individual panel, so now one shaded panel no longer affects the electricity generated by the others. We have now spent more on the panels but we hope that the improved efficiency will pay that back in a reasonable time.
Over 10 years ago we had solar PV panels installed, to generate electricity. It was estimated that we would get our money back in about 10 years, because the government pays as a feed in tariff (FIT) for each unit of electricity we generate. Any electricity we cannot use while it is being generated is fed back into the electricity grid. Any electricity that we can use ourselves is free to us, whereas we have to pay for it at other times. We are paid for the electricity we generate but at a much lower price than we have to pay to buy it at other times. Now we try to use appliances such as the washing machine in the late morning when we generate the most electricity. Without the FIT it would be a long time before we would get back what we had spent on the panels.
We originally had 2 sets of 8 panels and, if any panel of the 8 was shaded, all the others also generated less electricity. That doesn't happen with optimisers, which weren't available when we started. Unfortunately we later had to have repairs done to the chimney, which was expensive, but it gave us the chance to increase the electricity generated by fitting optimisers. While scaffolding was up there, we had an optimiser fitted to each individual panel, so now one shaded panel no longer affects the electricity generated by the others. We have now spent more on the panels but we hope that the improved efficiency will pay that back in a reasonable time.
The roof shown faces south east, so it was chosen for the solar panels. The ideal direction is south but that is not possible on this house. It is also important to avoid shading by trees , chimneys or other buildings at times when the sun is facing at a good angle (not oblique) to the roof. Fortunately there are no buildings or trees that cause shading but care was taken to minimise shading from chimneys, as can be seen in the other picture.
PROBLEMS
Click here to see problems we had with the work. |
A picture taken in the late afternoon, when the shadow of the chimney is over some of the 16 panels. Because the sun is an oblique angle to the panels, not much electricity is being generated from any of them. Earlier in the day there is no shading. The panels were deliberately not placed on the immediate right of each chimney, so that they are not shaded at the more favourable morning times.
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