Meet the ‘hydrogen home’: Is it key to a 100% clean grid?

Source: By Miranda Willson, E&E News reporter • Posted: Monday, December 21, 2020

A major gas utility is developing a “hydrogen home” to showcase how the fuel could help California achieve its clean energy goals.

Southern California Gas Co. plans to build a model home equipped with solar panels, a home battery and an electrolyzer that will convert solar power to green or carbon-free hydrogen. It will also contain a hydrogen fuel cell that can convert hydrogen back to electricity.

The hydrogen produced by the electrolyzer — in a process known as electrolysis — will be blended with natural gas to power appliances in the home, according to an announcement last week about the project.

While other utilities have identified green hydrogen as a key emerging resource, the hydrogen home is the first of its kind among U.S. utilities, according to SoCalGas.

“I am not aware of other utility projects similar to this one, but that’s not to say they don’t exist,” Jeffery Preece, senior program manager at the Low Carbon-Resources Initiative, a joint effort of the Electric Power Research Institute and the Gas Technology Institute, said in an email last week.

The model home is one of several recently announced green hydrogen projects from SoCalGas and San Diego Gas & Electric, both of which are owned by parent company Sempra Energy. In November, the two utilities announced plans for a demonstration project blending renewable hydrogen into natural gas pipelines in the Golden State (Energywire, Nov. 25).

The proposals follow announcements from utilities around the country of similar green hydrogen initiatives to help meet their emissions targets, such as Florida Power & Light Co.’s planned hydrogen plant (Energywire, July 27). Reducing the cost of electrolyzers to ramp up green hydrogen production is also listed as one of many goals in President-elect Joe Biden’s clean energy plan.

Green hydrogen has an important role to play in a decarbonized energy future because of its long-duration energy storage potential, said Neil Navin, vice president of clean energy innovations at SoCalGas. Most standard batteries can only store energy from intermittent renewable resources for several hours at a time, Navin said.

“Converting renewable electricity to a molecule — hydrogen — allows it to be stored for weeks, months or years. The hydrogen can then be converted back to clean electricity when it is needed to supplement solar and wind generation or battery storage,” Navin said in an email.

Ensuring that California’s electric grid remains reliable as the state reduces its carbon emissions has been a focal point in recent discussions about California’s climate policies. Long-duration batteries that can store energy for about eight hours or more are one option for ensuring grid reliability, but the technology is still limited by its high costs, according to a recent analysis by three California agencies. In the short term, some natural gas use will be needed for California to maintain reliability, the analysis said.

Storage and delivery of hydrogen is being considered in many places for a variety of applications, and coupling the abundant carbon-free gas with solar panels on homes could make sense, said Preece. Although it’s not clear whether electrolyzers have been used before in homes, electrolyzers that are currently employed in industrial and chemical processes are already large enough to meet the energy needs of a home, Preece said.

“It will be interesting to see an analysis showcasing the technology for this specific application,” Preece said, referring to SoCalGas’ model hydrogen home. “Hydrogen as an energy storage solution is nascent in today’s energy economy, but we believe it will expand over the next decade as more energy end users account for reliability and resiliency in the value proposition (in addition to direct costs).”

‘Pluses and minuses’

Although the model home would have a “drastically lower” carbon footprint than most homes today, Navin said, the continued use of natural gas means it would not be entirely carbon-neutral.

Given that California has set a goal for economywide carbon neutrality by 2045 and the currently high costs of green hydrogen production, some clean energy advocates are skeptical about the potential applications of SoCalGas’ hydrogen home. Most experts say a mix of about 80% natural gas and 20% hydrogen is the safe upper limit for blending hydrogen into existing gas pipelines without requiring significant grid retrofits.

It would make more sense to prioritize green hydrogen use for industrial sectors as well as shipping and aviation, rather than buildings, said Jeffrey Rissman, industry program director at Energy Innovation, a California-based policy firm focused on accelerating clean energy use and technologies.

“There are pluses and minuses to this idea,” Rissman said. “Electrolyzers at the moment are expensive, and there needs to be more research and development to drive down their costs to get wider deployment. They’re going to be more useful in industry than in homes.”

The project also arrives as SoCalGas is facing scrutiny for its efforts to stop California cities from passing ordinances that would phase out the use of natural gas for cooking, heating and other uses in new homes (E&E News PM, Oct. 29). The consumer advocacy arm of California’s Public Utilities Commission alleges that SoCalGas has used money from ratepayers to fund lobbying efforts against the growing slew of municipal gas bans and restrictions.

“We found evidence in our data requests that SoCalGas was using ratepayer money and spending that on their lobbying efforts, which is an illegal expenditure,” said Maya Chupkov, spokesperson for the California Public Advocates Office, an independent agency within the CPUC.

SoCalGas has said it has established protocols to make sure lobbying costs are not paid by ratepayers.

The company also dismissed allegations from environmental and technology groups that the hydrogen home was another example of an alleged campaign against electrification, adding that the system proposed in its model home would be more cost-effective than all-electric buildings powered exclusively by renewable electricity and batteries.

In its press release, the company cited a recent California Institute of Technology paper, which found that green hydrogen along with other long-duration storage tools could be less expensive options for decarbonizing the grid compared with conventional batteries and renewable electricity alone.

“The program is intended to provide an understanding of how to safely incorporate hydrogen, a zero-emission fuel, into the gas grid,” Navin said. “This is the first step toward the establishment of a statewide hydrogen injection standard.”

Other analyses, however, have shown that making buildings entirely electric is the cheapest way to eliminate their greenhouse gas emissions, said Rachel Fakhry, a policy analyst for the Natural Resources Defense Council’s climate and clean energy program.

“Is it cost effective for us to push [hydrogen] to do everything? The answer is no,” Fakhry said. “It has some good options where there are no alternatives. But for sectors where there are good alternatives like the building sector, it should not be channeled into those sectors.”