How Does Shade Affect Solar Panels
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How Does Shade Affect Solar Panels?
When buying and installing solar panels there are many factors that need to be taken into account, but few people ask the question 'How does shade affect solar panels?'.
Most people assume that solar panels do not work unless they are in direct, bright sunshine, so do not work at all in the shade. However, this is a misconception because modern solar panels work even in poor light conditions. But that said it is still important to understand the impact shade has on solar panels. This is especially important if your roof space is overlooked by buildings or trees. Understanding how shade affects solar panels and what you can do about it will ensure that you buy the right kind of panels for your situation and locate them properly.
Shade Reduces the Effectiveness of Solar Panels
A solar panel is made up of a grid of individual solar cells. Each individual solar cell that is covered by shade will stop working, whilst those not in the shade will continue to work. So if 20% of the cells in a panel are in heavy shade that panel will produce 20% less power than when the whole panel is clear of shadow. This means that the more time a panel is in shade the less it produces. Uni-solar solar panels are more shade tolerant than other types of solar panels, so if you cannot avoid shade consider these.
Shade Can Damage Solar Panels
Individual solar panel cells are very sensitive and do not like being constantly switched on and off. When some cells in the panel are not working the other cells work harder to try to compensate. As a result the solar cells that are not in shade have a tendency to overheat and burn out. There is a solution to this and that is to buy solar panels that are fitted with bypass diodes. However, even then shade is not good for solar panels, so should be avoided if possible.
Lessons to Learn
So in conclusion, shade makes solar panels less efficient and, unless they have the right internal protection, can lead to the solar panel being damaged. This damage means that your solar panels will under-perform even in direct sunshine.
Having your solar panels installed to reduce their exposure to shade is important. If to do so you have to have your solar panels set up in your garden instead of on your roof and pay a little extra you should do so. If you cannot avoid shade you must make sure that the solar panels you buy are the right kind.