Should natural gas be shipped or stored to supply power plants?

Following a series of winters featuring extreme cold episodes in the Northeastern U.S., power grid operators have engaged in exercises focused on assessing fuel deliverability to power plants, particularly natural gas. These studies have raised important issues and identified possible scenarios that could contribute to reliability problems during winter peaks, but have not evaluated the economics of specific solutions to winter-time fuel deliverability. This paper describes an expansion to a new modeling framework for gas and electric power transmission planning problems (the Combined Electricity and Gas Expansion, or CEGE model) that allows centralized or distributed natural gas storage to be evaluated alongside traditional planning alternatives such as transmission network expansion. Using a test system based on the gas and electric transmission topology in New England, we develop a a simple two-period gas storage model and use this model to evaluate economically valuable locations for distributed natural gas storage and compare the economic merits of increasing storage within New England versus expanding pipeline infrastructure to increase fuel deliverability to New England power plants within our test system. Initial simulations using this storage model suggest that the optimal placement for gas storage may be co-located with power plants to relieve binding pressure constraints in areas of the gas network close to gas-fired generation. Moreover, the economic consequences of extreme winter peak scenarios may be ameliorated at a lower cost with a mix of gas storage and pipeline expansions rather than via pipeline expansion alone.