The electrical grid is the central component of energy distribution and consumption, but the control of the same is currently underfunded and incapable of moving the nation toward a clean energy future. In a new study, electrochemical engineering expert Venkat Subramanian discusses the potential for implementing bottom-up renewable grid control with microgrids.

Subramanian is a member of The Electrochemical Society and the Washington Research Foundation Innovation Professor of Chemical Engineering and Clean Energy at the University of Washington.

“Our hypothesis is that the current grid control method, which is a derivative of traditional grid control approaches, cannot utilize batteries efficiently,” Subramanian says. “In the current microgrid control, batteries are treated as “slaves” and are typically expected to be available to meet only the power needs. This way of optimization will not yield the best possible outcome for batteries.”

Microgrids are local energy grids the can disconnect from the traditional grid and operate autonomously. Microgrids have the ability to strengthen and reinforce the traditional grid because they can function even when the main grid is down and are optimal for integrating renewable sources of energy. However, energy storage technology accounts for the highest cost in developing a microgrid, yet is the least understood component and tends to be the most poorly integrated. If batteries and microgrids could interact at a higher efficiency, new possibilities could arise for the future of energy distribution.

Subramanian and his team recently published an open access paper in the Journal of The Electrochemical Society, “Direct, Efficient, and Real-Time Simulation of Physics-Based Battery Models for Stand-Alone PV-Battery Microgrids,” describing how microgrids are becoming more widespread and could pave the way for future energy distribution.

“In a recently published paper, we show that simulation of the entire microgrid is possible in real-time. We wrote down all of the microgrid equations in mathematical form, including photovoltaic (PV) arrays, PV maximum power point tracking (MPPT) controllers, batteries, and power electronics, and then identified an efficient way to solve them simultaneously with battery models,” Subramanian says. “The proposed approach improves the performance of the overall microgrid system, considering the batteries as collaborators on par with the entire microgrid components. It is our hope that this paper will change the current perception among the grid community.”

Subramanian and his team believe that with the right battery and grid control strategies, microgrids could be more efficient and economically feasible.

“In our humble opinion, energy and information flow should be bidirectional and a renewable grid should be modeled and controlled simultaneously aiming for the best possible outcomes for all the devices including batteries,” Subramanian says. “This will require strong collaboration between battery and grid modelers, application of nonlinear model predictive control techniques pioneered and championed by chemical engineering and other control communities. Both Pacific Northwest National Laboratory (grid modernization initiative) and the University of Washington have strong leaders in grid control and modeling. We hope to make progress in this topic.”