In 1976, the first amorphous silicon photovoltaic (PV) cells were produced, offering a meagre energy conversion rate of 1.1%; 20 years later, the École Polytechnique Fédérale de Lausanne in Switzerland achieved a conversion rate of 11% using a photo-electrochemical process. Another 20 years later, the average conversion rate of commercial solar panels is about 20-23%, although the University of South Wales in Australia reached a world record in 2016, improving the rate to 34.5% by using a prism to maximize energy extraction from the sun.
As photovoltaic solar panels have become better at converting energy from the sun into electricity and their costs are going down, they are becoming a more common investment for businesses and individuals. Not only is it green energy, but it reduces energy bills and you can even make money reselling your surplus to your electricity provider.
However, there are still concerns about how efficient those systems are when climatic conditions are less than optimum. Will they work on cloudy days? How about if your roof gets shaded during the day?
What if my solar panels can’t be installed in direct sunlight?
Solar panels produce electricity from the photons present in natural daylight, rather than from the sunlight itself, so panels don’t actually need to be installed in direct sunlight to work. Heat isn’t a factor in how much electricity PV solar panels can generate either so a cool Spring day can be as productive, if not more than a hot Summer day.
It is true that direct sunlight provides optimum conditions for solar systems but you will still get significant benefits from solar electricity even if your property doesn’t offer the perfect environment.
Does shade affect PV solar panels? Since PV panels use daylight to produce electricity, they will indeed be affected by shade, but they are increasingly efficient and will still produce some energy, depending on how much shade covers them.
Some designs and components making up solar panel installations will have a Christmas Tree light effect - where if one panel drops in performance, others will also follow suit. Other technologies and designs available will provide compensation to a shaded panel by managing other panels to counter the shade effect. Another option is to use Optimisers and Microinverters, which will assist where shading may be an issue.
So, in conclusion, although solar panels can cope with shade, it is best to look for a site with as little of it as possible and seek expert advice on your design.
How about clouds?
Nowadays, solar panels include various concentrators which use lenses and mirrors to maximise any light reaching their PV cells. This means that, on cloudy days, your solar system will still be able to produce electricity. A recent study by the U.S. Department of Energy has shown that production of electricity by large solar panels on cloudy days fluctuated less than in small panels, so the size of the panels used for your installation is something to keep in mind.
Germany isn’t known for its particularly sunny weather and has many cloudy days. Yet, it is the world’s leader in solar energy use; evidence that, even with a reduced productivity, solar panels are worth the investment, both for individuals and businesses.
In conclusion, although solar panels have become more efficient at dealing with various conditions, they are still affected by anything that reduces the reception of daylight. So if your roof or garden has a less-than-ideal environment for solar energy production, or you live in an area that is prone to bad weather, you can still benefit from a solar system.
If you are considering having solar panels installed and need friendly, expert advice, contact Harissons Energy on 0800 00 33 54, or through our online form. We offer a free site visit from a Harrisons Energy expert and a range of energy solutions including solar panels, heat pumps, ventilation systems and insulation – everything you need to keep you comfortable in a healthy and green home.