The increasing penetration of solar renewable energy and its variability can cause steep ramp fluctuations of conventional power plants. Due to improved efficiency in solar, wind and lithium-ion battery technology and significant growth in manufacturing volume the cost to produce electricity from these renewables has made these technologies more than competitive with traditional sources. However, seasonal variations will require longer-duration storage (i.e. days to months). These longer duration storage technologies may also be used for short-duration applications in a “stacked-benefit” approach. For example, they may be used to smooth out the fluctuations, decreasing the wear and tear of power plants and increasing grid reliability with longer term energy storage. In Florida cloud cover of a PV field can cause rapid fluctuations of PV output demanding a fast response to smooth out the PV electric power output. A polymer electrolyte membrane (PEM) electrolyzer can serve as a utility controllable load by producing hydrogen which can be sold or converted back to electricity using a PEM fuel cell. Though hydrogen enables higher energy density storage when compared to batteries, it has a lower energy. Moreover, the cost associated with hydrogen production especially compression of hydrogen is high [1], although these costs like solar, wind and batteries are expected to decrease substantially by 2030. This report will present simulation results that will address issues with PV production by dispatching hydrogen and flow battery technologies.

Various combinations of PV production of electricity, hydrogen (production and consumption) and use of a redox flow battery for providing a path to net zero emissions energy production were pursued to achieve long-term 100% renewable energy. Real-time PV data was taken from an 8.9 MW_AC solar farm from Orlando Utilities Commission’s Stanton Energy Center. Three cases were considered for developing the PV smoothing algorithm in MATLAB. Specifically, the simulations explore managing electrolyzer load assuming three different operating modes: PV smoothing, low-cost solar consumption, and combined PV smoothing and low-cost solar consumption. In the first case, the algorithm was used to determine the size of the PEM electrolyzer and redox flow battery for the 8.9 MW_AC solar field. In the second case, low cost solar was used without any PV smoothing. In the third case, both PV smoothing and the low cost solar was used to optimize the system. The cost of hydrogen production and the impact on PV output was evaluated. Results will be presented that maximize the capacity factor of the electrolyzer, while decreasing the cost associated with hydrogen production.

[1] Hamed Haggi, Paul Brooker, Wei Sun, James M. Fenton, “Hydrogen and Battery Storage Technologies for Low-Cost Energy Decarbonization in Distributed Networks”, arXiv, 11 (2022). https://doi.org/10.48550/arXiv.2202.02711