Canadian researchers have done the math on optimizing PV output

Researchers at the University of Waterloo’s Department of Applied Mathematics, in Canada, claim the output of installed PV systems could be significantly raised by applying an algorithm they have developed. The solution, claim the researchers, optimizes maximum power point (MPP) tracking and enables better response to changes in the weather or other generation conditions.

The algorithm, described in the paper Nonlinear Optimal Feedback Control and Stability Analysis of Solar Photovoltaic Systems – published in IEEE Transactions on Control Systems Technology – focuses on dealing with oscillations in a system’s maximum power point and minimizing the energy lost during such shading or weather-driven fluctuations.

The team simulated applying the algorithm to PV systems under varying weather conditions and found it offered improved performance in the convergence rate and amplitude of oscillations around the MPP, compared with existing results.

Scaled up benefits

“We’ve developed an algorithm to further boost the power extracted from an existing solar panel,” said Milad Farsi, a PhD candidate at Waterloo’s Department of Applied Mathematics. “We do not change the hardware or require additional circuits in the solar PV system. What we developed is a better approach to controlling the hardware that already exists.”

The simulations demonstrated improved output of up to 138.9 kWh per year for a small residential solar array of a dozen 335 W modules.

“The savings may not seem significant for a small, home-use solar system,” said Jun Liu, a professor at the applied mathematics department, “but could make a substantial difference in larger scale ones such as a solar farm or in an area including hundreds of thousands of local solar panels connected to the power grid.”

Liu went on to calculate that if the algorithm was applied to Canada’s largest operational PV plant – the 97 MW Sarnia facility in Ontario – its output could be boosted by as much as 960 MWh per year. The researchers added, in environments where PV is prone to fast changing weather conditions, such as most of Canada, even more substantial improvements could be achieved.