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One of the key challenges that still facing the adoption of renewable energy systems is having a powerful energy storage system (ESS) that can store energy at peak production periods and return it back when the demand exceeds the supply. In this paper, we discuss the costs associated with storing excess energy from power grids in the form of hydrogen using proton exchange membrane (PEM) reversible fuel cells (RFC). The PEM-RFC system is designed to have dual functions: (1) to use electricity from the wholesale electricity market when the wholesale price reaches low competitive values, use it to produce hydrogen and then convert it back to electricity when the prices are competitive, and (2) to produce hydrogen at low costs to be used in other applications such as a fuel for fuel cell electric vehicles. The main goal of the model is to minimize the levelized cost of energy storage (LCOS), thus the LCOS is used as the key measure for evaluating this economic point. LCOS in many regions in United States can reach competitive costs, for example lowest LCOS can reach 16.4¢/kWh in Illinois (MISO trading hub) when the threshold wholesale electricity price is set at $25/MWh, and 19.9¢/kWh in Texas (ERCOT trading hub) at threshold price of $20/MWh. Similarly, the levelized cost of hydrogen production shows that hydrogen can be produced at very competitive costs, for example the levelized cost of hydrogen production can reach $2.54/kg-H 2 when using electricity from MISO hub. This value is close to the target set by the U.S. Department of Energy. Levelized cost of energy storage (LCOS) curves for several regions in the United States. Image 1 • A model to calculate the levelized cost of energy storage for reversible fuel cells. • RFC system as energy storage system can increase the resiliency of the power grids. • RFC can be designed to store electricity and produce hydrogen for other uses. • Roundtrip efficiency and capital cost are key factors that shape the LCOS in RFC. [ABSTRACT FROM AUTHOR]

• A mathematical model to calculate the LCOS for reversible fuel cells and Li-ion batteries. • Techno-economic model for a standalone PV solar system in green energy buildings. • Uncertainty and simulation cost analyses of energy storage systems used in green buildings. Energy storage systems (ESSs) were introduced to overcome the risks posed by energy curtailment. In this paper, we compare the Levelized cost of storage (LCOS) for PEM Reversible Fuel Cells, Solid Oxide Fuel Cells, and Lithium-Ion Batteries in three different locations in the United States (Tucson, Seattle, and Rochester) that are characterized by different energy consumption profiles. This research examines three commercial buildings of different sizes: small, medium, and large, with three occupancy profiles: low, medium, and high energy consumption in each of the three locations. The objective is to quantify the impact of uncertain demand and uncertain financial parameters on the LCOS. The results show that all ESSs can represent an attractive alternative to energy curtailment regardless of the building size or the occupancy profile. Further, the results show that fuel cells are a better fit for demand uncertainty as they are more resilient to changes and remain attractive despite that. The uncertainty analysis showed that the minimum LCOS was $0.049/kWh, and it was for a PEM-RFC in a small building in Tucson under high energy consumption behavior. Oppositely, the maximum LCOS was $0.679/kWh, and that was for a large building in Seattle under high energy usage occupancy as well. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen is a flexible energy carrier that can be produced in various ways and support a variety of applications including industrial processes, energy storage and electricity production, and can serve as an alternative transportation fuel. Hydrogen can be integrated in multiple energy sectors and has the potential to increase overall energy system flexibility, improve energy security, and reduce environmental impact. In this paper, the interactions between fuel cell electric vehicles (FCEVs), hydrogen production facilities, and the electric power grid are explored. The flexibility of hydrogen production systems can create synergistic opportunities to better integrate renewable sources into the electricity system. To quantify this potential, we project the hourly system-wide balancing challenges in California out to 2025 as more renewables are deployed and electricity demand continues to grow. Passenger FCEV adoption and refueling behavior are modeled in detail to spatially and temporally resolve the hydrogen demand. We then quantify the system-wide balancing benefits of controlling hydrogen production from water electrolysis to mitigate renewable intermittency, without compromising the mobility needs of FCEV drivers. Finally, a control algorithm that can achieve different objectives, including peak shaving, valley filling, and ramping mitigation is proposed. Our results show that oversizing electrolyzers can provide considerable benefits to mitigate renewable intermittency, while also supporting the deployment of hydrogen vehicles to help decarbonize the transportation sector. Highlights • Interactions between FCEVs and electric power systems are studied. • FCEV powertrain, adoption and refueling behavior are modeled. • Two controllers are designed to mitigate California “Duck Curve” problems. • Controllable H 2 production systems can facilitate renewable energy deployment. [ABSTRACT FROM AUTHOR]