Optimal Heat Recovery and Electricity Production from a Proton Exchange Membrane Fuel Cell’s Operation

In this paper a comprehensive optimal control model was developed, which maximizes the thermal energy recovery from the PEMFC to the hot water storage tank (HWST) whilst maximizing the electrical energy supplied from the solar PV modules to the load and minimizes the energy cost of the grid. Actual and accurate exogenous historic data obtained from an established weather station is utilized for this study. Simulations of the optimal switching control of a PEMFC water heating system were conducted successfully with the SCIP (solving constrained integer programs) solver in the optimization toolbox in MATLAB. The proposed optimal control regime is evaluated a standard utility grid system (baseline), where the load is purely supplied by the grid which consumed 102.48 kWh. The simulation results of the proposed optimal control model yield the grid supplied 5.57 kWh to the load and 53.69 kWh to the PEMWE, whilst the PEMFC produced 55.05 kWh for the load demand. Furthermore, a maximum thermal energy recovery of 4.15 × 106 J, which is equivalent to 1.15 kWh, is achieved. By recovering the generated heat from the PEMFC, the time period for the membrane to degrade to a thickness of 50% could be prolonged by 0.91 years.