Two SDG&E Green Hydrogen Pilots Aim to be Online in 2022

By Published On: August 10, 2021

San Diego Gas & Electric launched two green hydrogen demonstration projects geared to help start the decarbonization of its system. Both are expected to be online before the end of next year.

SDG&E’s Borrego Springs microgrid

One will produce green hydrogen from excess solar from two large projects plus residential photovoltaic rooftops in Borrego Springs in Eastern San Diego County. The solar-split hydrogen is intended to provide long-duration storage to the grid and power the remote desert community when its disconnected from the grid. The other project will add green hydrogen, also produced by solar power, to the utility’s 565 MW Palomar natural gas-fired plant in Escondido in northern San Diego County. It will be blended with natural gas and fed into plant turbines and also supply a hydrogen vehicle fueling station.

Both projects will produce hydrogen from water using hydrolyzers. 

A major challenge is the finding the water to supply the hydrogen in resource-constrained regions. The utility is working with the Borrego Water District to obtain town water for the Borrego Springs pilot. It also is looking into other possible water resources, Spokesperson Helen Gao said.

In addition, the cost of producing green hydrogen has been prohibitive but new regional and federal efforts are aimed at driving down the costs over this decade.

In early June, DOE announced its Hydrogen Shot program, which seeks  to cut the cost of clean hydrogen to $1 per kilogram by 2030, an 80% decrease from current levels. And it is seeking regional projects. Earlier, the Los Angeles Department of Water & Power announced a public-private coalition, known as HyDeal LA, to scale up the production of hydrogen split from water and powered by excess solar and other renewable resources, in order to drive down costs. SDG&E sister utility, SoCalGas, is one of the project partners.

Major costs of renewable hydrogen are the power to supply electrolyzers and the cost of the electrolyzers themselves.

That didn’t stop Jeff Martin, Sempra Energy CEO, from telling financial analysts last week that green hydrogen and renewable gas are expected to provide “a unique opportunity” to increase the company’s market share.

SDG&E is seeking competitive bids for its two green hydrogen projects. It declined to provide cost estimates because it “would compromise the integrity of the bidding process,” Gao said.

Borrego Springs

SDG&E’s Borrego Spring project aims to create a 250kW/2MWh+ of hydrogen-based energy storage that can feed into the California Independent System Operator grid for more than eight hours. The second system in the works is a 8MW/16MWh battery energy storage system to support the existing utility microgrid in the remote community of some 2,800 residences. Electricity from the new hydrogen storage would flow in the direction of the community during disruptions when it is islanded from the grid.

The Borrego microgrid is already fueled by surrounding solar resources, including from a 26 MW solar farm and a 6.5 MW PV systems as well as 5 MW of residential solar roofs in Borrego Springs. None of that solar is owned by SDG&E.

The Borrego Springs microgrid was one of the first community-scale projects launched a decade ago. The remote region is often battered by monsoonal storms that have at times knocked out the only transmission pole supplying utility customers. The initial project, begun in 2011, included 700 kW of rooftop solar and two 1.8 MW diesel generators to power the microgrid. Homes were outfitted with automated controls that cut back power usage in response to price and power supply signals sent by the utility, as well as other automated monitors and controls embedded in the grid. Two battery systems were later added.

Last year, the utility landed a $4.5 million grant from the Department of Energy to retrofit the system with advanced inverters and an energy management system to ensure its stability when being powered fully by solar resources. 

SDG&E’s microgrid project initially was supported by DOE, which chipped in $7.4 million, and the California Energy Commission, which provided $2.8 million, as well as SDG&E, which spent $4.1 million.

Elizabeth McCarthy

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