Sara Mirbagheri Golroodbari on solving the solar panel shading problem
Solar panels are mostly found on roofs - this is where the most direct sunlight is found. But what happens when these PV panels find themselves in the shade of trees, chimneys, TV satellite dishes or other buildings? And what are the possibilities for solar panels on the sea?
Sara Mirbagheri Golroodbari is a PhD researcher at the Copernicus Institute of Sustainable Development at Utrecht University. In this interview she tells about her research finding solutions for the solar panel shading problem, as well as the tests for floating solar panels taking place on campus.
Firstly, why is shade such a problem for solar panels?
“A solar panel, also called PV panel, is split into three or more sections. If only one small leaf happens to shade a tiny part of one of these sections, the energy output can be significantly affected. Depending on the intensity of the shade, the whole section produces very little energy or even no energy at all. This is a big problem because it’s difficult to avoid shade completely, especially in cities, where more and more people are putting solar panels on their own roofs. We’re losing so much potential energy production!”
How is your research contributing to solving this problem?
“To combat this I’m working on two things. The first is making the sections in a solar panel smaller so there are more sections in one panel. We could produce much more energy when the shade from a few leaves only blocks three small sections instead of a third of the whole panel.
And then, instead of using diodes, which conduct energy in one direction, we are using active diodes, which are electronic circuits. Active diodes help to generate as much energy as possible from each group of cells. Unlike diodes they do not bypass the whole section when there is shading. Both of these solutions would be a big advantage for homeowners.”
What kind of impact will this new and improved panel have?
“If a shade resilient solar panel can be introduced to the market, customers will be able to produce more energy on their roofs. When more green energy is consumed and produced we reduce our reliance on fossil fuels and can help mitigate the effects of climate change.”
You’re also working on a project developing floating solar panels. Tell us about that.
“We have a new research project that compares a floating PV system on the North Sea and one on land, on campus here at Utrecht University. We know the cooling effect from the water can improve efficiency, but at the moment we don’t have much of an idea about how other issues affect our system.
We will look at the difference between the PV system on the water and on land. What are the challenges we haven’t encountered before? This could be a really appropriate option for a country surrounded by a lot of sea like the Netherlands.”
I think solar will become the first option for residential buildings.
And finally, what kind of future do you see for solar panels?
“I think solar will become the first option for residential buildings. Using solar panels to replace conventional building materials for roofs, skylights, or facades - so-called building-integrated photovoltaics - is on the way. We’ll soon have buildings that can produce whatever they need for electricity. And even now there are cars coming on to the market that will be powered solely by solar panels on the car. There is such a lot happening that will reduce our reliance on fossil fuels”.
Further reading
Mirbagheri Golroodbari, S. Z., de Waal, A., & Van Sark, W. (2019). Proof of concept for a novel and smart shade resilient photovoltaic module. IET Renewable Power Generation. doi.org/10.1049/iet-rpg.2018.6127
Mirbagheri Golroodbari, S. Z., De Waal, A., & van Sark, W. (2018). Improvement of Shade Resilience in Photovoltaic Modules Using Buck Converters in a Smart Module Architecture. Energies, 11(1), 250. doi.org/10.3390/en11010250