We’ve covered solar energy systems working on overcast days, but what about homes with a lot of shade?
Can houses with lots of shade still use a solar energy system?
We often hear a common assumption that solar panels don’t work unless they’re in the direct line of sight to the sun. This isn’t true.
“However, they won’t supply as much generated energy as their system is able to supply. Solar PV systems supply the highest levels of energy generation when bright sunlight is hitting them directly. The theory is that your solar PV systems will still be able to generate at least 25% of the energy on a cloudy day compared to a sunny day because solar PV generates energy from 2 different types of light; visible light and infrared light. Both are still available on a cloudy day, the former is a bit darker, but the latter is unaffected.” source
Cloudy days are unavoidable and solar panel technology is built with overcast days in mind. But they’re not built for regular and consistent shade.
Solar panels (or solar PV) compromise a part of a solar energy system that connects to an inverter. If your solar energy system uses bypass diodes, the system can ‘bypass’ the solar cells that aren’t collecting energy and collect them from those that are. If, for example, you have 20 solar panels and 10 of them are in the shade during the day, the remaining 10 panels will supply energy. So if some of the energy system is in the shade the solar panels that aren’t will continue absorbing solar energy and supply it to the system, but obviously the system is no longer working at full capacity.
So, in the case of homes with shaded areas, the energy system is going to create energy in a similar manner. ie. if the sunlight is reduced the effectiveness of the solar panels are also reduced.
Don’t plant trees that will grow and create shade over your solar PV
If even a part of your solar energy system receives shade through some or all of the day the effectiveness of your energy system is greatly decreased. If you want a solar energy system for your home the area you plan to allocate for your solar panels will need to be shade-free.