Lifecycle Cost Analysis of Hydrogen Versus Other Technologies for Electrical Energy Storage

Abstract

online ordering: http://www.ntis.gov/ordering.htm Printed on paper containing at least 50% wastepaper, including 20% postconsumer waste iii Executive SummaryAs renewable electricity becomes a larger portion of the electricity generation mix, new strategies will be required to accommodate fluctuations in energy generation from these sources. One of the primary strategies proposed for integrating large amounts of renewable energy is using energy storage to absorb excess electricity-generating capacity during times of low demand and/or high rates of generation by renewable sources and then reconverting this stored energy into electricity during periods of high demand and/or low renewable generation.Various energy storage technologies have been developed or proposed. The goal of this analysis was to develop a cost survey of the most-promising and/or mature energy storage technologies and compare them with several configurations employing hydrogen as the energy carrier. A simple energy arbitrage scenario was developed for a mid-sized energy storage system consisting of a 300-MWh nominal storage capacity that is charged during off-peak hours (18 hours per day on weekdays and all day on weekends) and discharged at a rate of 50 MW for 6 peak hours on weekdays.For all the hydrogen cases, off-peak and/or excess renewable electricity is used to electrolyze water to produce hydrogen, which is stored in compressed gas tanks or underground geologic formations. The hydrogen is reconverted into electricity using a polymer electrolyte membrane (PEM) fuel cell or hydrogen expansion combustion turbine. The hydrogen storage scenarios are compared with the use of several battery systems (nickel cadmium, sodium sulfur, and vanadium redox), pumped hydro, and compressed air energy storage (CAES).All the energy storage systems are evaluated for the same energy arbitrage scenario using consistent financial and operational assumptions. Costs and performance parameters for the technologies were gathered from literature sources and, in the case of the hydrogen expansion combustion turbine, Aspen Plus modeling. Producing excess hydrogen for use in vehicles or backup power is also evaluated. Two production levels are analyzed: 1,400 kg/day (roughly equivalent to the U.S. Department of Energy's standard model for smallscale distributed hydrogen production) and 12,000 kg/day. As for the purely energy arbitrage scenarios, it is assumed that hydrogen would be produced with offpeak/renewable electricity. Cost results for the analysis are presented in terms of the annualized ("levelized" 1 Figure ES -1 ) cost for producing the energy output from the storage system: electricity fed back onto the grid during peak hours ($/kWh) and, in the case of producing excess hydrogen for vehicles, hydrogen ($/kg).summarizes the comparison of levelized cost of delivered electricity for hydrogen (green bars) and competing technologies (blue bars). For each technology, high-cost, mid-range, and low-cost cases were analyzed, and sensitivity analyses were 1 The leve...

Value assessment of hydrogen-based electrical energy storage in view of electricity spot market

“…Comparing to the other storage technologies that can also take advantage of performing energy arbitrage in a electricity spot market, the study performed in [35] showed that compressed air energy storage (CAES) and pumped hydro were the two winners. The comparison was performed based on a unified size of 300 MWh scale energy storage with a discharge rate of 50 MW, while using annualized cost for producing the energy output from the storage system as the metric: electricity fed back onto the grid during peak hours and, in the case of producing excess hydrogen for vehicles, hydrogen.…”

Hydrogen Cryomagnetics for Decentralised Energy Management and Superconductivity

“…Polymer electrolyte membrane electrolysers [7] are being developed and are expected to have increased operational efficiencies and could potentially lower the overall costs of the electrolyser. Different efficiencies were stated for the compression of hydrogen ranging from low efficiencies of 52 % [8] to high efficiencies of 85 % [9].…”

“…The proton exchange membrane fuel cell (PEMFC) is the most advanced for transport and stationery applications and has an efficiency of 53.5 % [8]. Another fuel cell that is in the research phase is the solid oxide fuel cell [10] (SOFC) which is estimated to have higher efficiencies due to high operating temperatures in which some of the heat can be used to supply heat for domestic purposes.…”

“…This decentralised production of hydrogen can be used for domestic, transport and industrial applications, making it a cryogenic that can be used both as an energy carrier and a cryogenic medium. 8 Decentralised production of hydrogen via zero-CO 2 emission processes and uses as an energy carrier, energy storage medium and cooling cryogenic medium. The actual superconducting devices to benefit from the synergy with iLH 2 are SMES, Flywheel, MRI, DC cables for datacentres and homopolar wind generators.…”

Broad Overview of Energy Efficiency and Renewable Energy Opportunities for Department of Defense Installations

“…This is an attractive energy storage system that combines several known subsystems into a complete system. NREL has reported on an analysis of hydrogen storage versus other electrical energy storage systems (Steward et al 2009). …”