Energy Initiative Blogs

Improving Efficiencies of Commercial and Residential Solar Panels

by Zong Liu | Jul 28, 2015

Improving Efficiencies of Commercial and Residential Solar Panels
Joey Liu- Energy Initiative Intern

People have varying opinions on electricity generation and the integration of renewables in the U.S.  In my opinion, U.S. electrical generation is extremely inefficient and renewables should replace fossil fuels, if we want future generations to have electricity. According to the Solar Industry Data Administration, there are over 645,000 homes and businesses with solar panels installed. Altogether, these panels generate about 20 Megawatts of electricity, enough to power 4 million American homes. Although this number seems large, it has the potential to be larger. One way to achieve this goal is to make solar panels more efficient.

I conducted an experiment on the effect of shade on solar voltaic arrays. Shade has a much larger effect on electrical generation than you might think. Just because half of the panel is covered in shade does not mean that half of the panel stops working. In fact, in order to lose over half of the energy generated from a monocrystalline solar panel less than 20% of the cell has to be shaded. This information should be alarming, especially in Chicago, due to the potential for shading solar panels such as snow, leaves, animal droppings, and trees. With this information, any residential solar panel owner must constantly keep his or her solar panels clean and shade free in order to keep the solar panels working efficiently.

In order to combat the problem of shading, companies run three-dimensional simulations in order to determine the best possible placement to reduce shade on an installed solar panel. Another method that helps reduce the effect of shade on solar panels is to attach an inverter with maximum power point tracking (MMPT) to the array. An inverter with MMPT technology greatly improves a shaded array by averaging out the currents within two or more solar panels. The way a typical solar array is set up, if one cell does not generate a current that surpasses a threshold then the surrounding cells also fail to generate energy as well. By sharing the current from a shaded cell and a non-shaded cell, it is more likely for both of these cells to surpass that threshold, preventing the failure of the entire array. If every pair of panels in an array is connected with an inverter with MMPT, then it will greatly reduce the chances of a solar array failing due to shade.


Link to my research project -