Making the case for hydrogen in a zero-carbon economy

As the United States races to execute its extremity of zero-carbon energy procreation by 2035, vigor providers are swiftly ramping up renewable resources specified arsenic star and wind. But due to the fact that these technologies churn retired electrons lone erstwhile the prima shines and the upwind blows, they request backup from different vigor sources, particularly during seasons of precocious electrical demand. Currently, plants burning fossil fuels, chiefly earthy gas, capable successful the gaps.

"As we determination to much and much renewable penetration, this intermittency volition marque a greater interaction connected the electric powerfulness system," says Emre Gençer, a probe idiosyncratic astatine the MIT Energy Initiative (MITEI). That's due to the fact that grid operators volition progressively edifice to fossil-fuel-based "peaker" plants that compensate for the intermittency of the adaptable renewable energy (VRE) sources of prima and wind. "If we're to execute zero-carbon electricity, we indispensable regenerate each greenhouse gas-emitting sources," Gençer says.

Low- and zero-carbon alternatives to greenhouse-gas emitting peaker plants are successful development, specified arsenic arrays of lithium-ion batteries and hydrogen powerfulness generation. But each of these evolving technologies comes with its ain acceptable of advantages and constraints, and it has proven hard to framework the statement astir these options successful a mode that's utile for policymakers, investors, and utilities engaged successful the cleanable vigor transition.

Now, Gençer and Drake D. Hernandez SM '21 person travel up with a exemplary that makes it imaginable to pin down the pros and cons of these peaker-plant alternatives with greater precision. Their hybrid technological and economic analysis, based connected a elaborate inventory of California's powerfulness system, was published online past period successful Applied Energy. While their enactment focuses connected the astir cost-effective solutions for replacing peaker powerfulness plants, it besides contains insights intended to lend to the larger speech astir transforming vigor systems.

"Our study's indispensable takeaway is that hydrogen-fired powerfulness procreation tin beryllium the much economical enactment erstwhile compared to lithium-ion batteries—even today, erstwhile the costs of hydrogen production, transmission, and retention are precise high," says Hernandez, who worked connected the survey portion a postgraduate probe adjunct for MITEI. Adds Gençer, "If determination is simply a spot for hydrogen successful the cases we analyzed, that suggests determination is simply a promising relation for hydrogen to play successful the vigor transition."

Adding up the costs

California serves arsenic a stellar paradigm for a swiftly shifting powerfulness system. The authorities draws much than 20 percent of its energy from star and astir 7 percent from wind, with much VRE coming online rapidly. This means its peaker plants already play a pivotal role, coming online each evening erstwhile the prima goes down oregon erstwhile events specified arsenic vigor waves thrust up energy usage for days astatine a time.

"We looked astatine each the peaker plants successful California," recounts Gençer. "We wanted to cognize the outgo of energy if we replaced them with hydrogen-fired turbines oregon with lithium-ion batteries." The researchers utilized a halfway metric called the levelized outgo of energy (LCOE) arsenic a mode of comparing the costs of antithetic technologies to each other. LCOE measures the mean full outgo of gathering and operating a peculiar energy-generating plus per portion of full energy generated implicit the hypothetical beingness of that asset.

Selecting 2019 arsenic their basal survey year, the squad looked astatine the costs of moving earthy gas-fired peaker plants, which they defined arsenic plants operating 15 percent of the twelvemonth successful effect to gaps successful intermittent renewable electricity. In addition, they determined the magnitude of c dioxide released by these plants and the disbursal of abating these emissions. Much of this accusation was publically available.

Coming up with prices for replacing peaker plants with monolithic arrays of lithium-ion batteries was besides comparatively straightforward: "There are nary method limitations to lithium-ion, truthful you tin physique arsenic galore arsenic you want; but they are ace costly successful presumption of their footprint for vigor retention and the mining required to manufacture them," says Gençer.

But past came the hard part: nailing down the costs of hydrogen-fired energy generation. "The astir hard happening is uncovering outgo assumptions for caller technologies," says Hernandez. "You can't bash this done a lit review, truthful we had galore conversations with instrumentality manufacturers and works operators."

The squad considered 2 antithetic forms of hydrogen substance to regenerate earthy gas, 1 produced done electrolyzer facilities that person h2o and energy into hydrogen, and different that reforms earthy gas, yielding hydrogen and c discarded that tin beryllium captured to trim emissions. They besides ran the numbers connected retrofitting earthy state plants to pain hydrogen arsenic opposed to gathering wholly caller facilities. Their exemplary includes recognition of apt locations passim the authorities and expenses progressive successful constructing these facilities.

The researchers spent months compiling a elephantine dataset earlier mounting retired connected the task of analysis. The results from their modeling were clear: "Hydrogen tin beryllium a much cost-effective alternate to lithium-ion batteries for peaking operations connected a powerfulness grid," says Hernandez. In addition, notes Gençer, "While definite technologies worked amended successful peculiar locations, we recovered that connected average, reforming hydrogen alternatively than electrolytic hydrogen turned retired to beryllium the cheapest enactment for replacing peaker plants."

A instrumentality for vigor investors

When helium began this project, Gençer admits helium "wasn't hopeful" astir hydrogen replacing earthy state successful peaker plants. "It was benignant of shocking to spot successful our antithetic scenarios that determination was a spot for hydrogen." That's due to the fact that the wide terms tag for converting a fossil-fuel based works to 1 based connected hydrogen is precise high, and specified conversions apt won't instrumentality spot until much sectors of the system clasp hydrogen, whether arsenic a substance for proscription oregon for varied manufacturing and concern purposes.

A nascent hydrogen accumulation infrastructure does exist, chiefly successful the accumulation of ammonia for fertilizer. But tremendous investments volition beryllium indispensable to grow this model to conscionable grid-scale needs, driven by purposeful incentives. "With immoderate of the clime solutions projected today, we volition request a c taxation oregon c pricing; different cipher volition power to caller technologies," says Gençer.

The researchers judge studies similar theirs could assistance cardinal vigor stakeholders marque better-informed decisions. To that end, they person integrated their investigation into SESAME, a beingness rhythm and techno-economic appraisal instrumentality for a scope of vigor systems that was developed by MIT researchers. Users tin leverage this blase modeling situation to comparison costs of vigor retention and emissions from antithetic technologies, for instance, oregon to find whether it is cost-efficient to regenerate a natural gas-powered works with 1 powered by hydrogen.

"As utilities, industry, and investors look to decarbonize and execute zero-emissions targets, they person to measurement the costs of investing successful low-carbon technologies contiguous against the imaginable impacts of clime alteration moving forward," says Hernandez, who is presently a elder subordinate successful the vigor signifier astatine Charles River Associates. Hydrogen, helium believes, volition go progressively cost-competitive arsenic its accumulation costs diminution and markets expand.

A survey radical subordinate of MITEI's soon-to-be published Future of Storage study, Gençer knows that hydrogen unsocial volition not usher successful a zero-carbon future. But, helium says, "Our probe shows we request to earnestly see hydrogen successful the vigor transition, commencement reasoning astir cardinal areas wherever hydrogen should beryllium used, and commencement making the monolithic investments necessary."

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More information: Drake D. Hernandez et al, Techno-economic investigation of balancing California's powerfulness strategy connected a seasonal basis: Hydrogen vs. lithium-ion batteries, Applied Energy (2021). DOI: 10.1016/j.apenergy.2021.117314

This communicative is republished courtesy of MIT News (web.mit.edu/newsoffice/), a fashionable tract that covers quality astir MIT research, innovation and teaching.