As the United States races to achieve its goal of zero-carbon electricity generation by 2035, energy providers are ramping up the installation of renewable resources such as solar and wind. But being somewhat weather dependent, renewables lack the possibility of achieving a continuous supply on their own due to their inherent intermittence.
So, what about batteries? Can Hydrogen be a viable option?
The Golden State is a shining example of a rapidly changing power system. Here solar accounts for more than 20% of the electricity, while wind power accounts for about 7%. As we move to more and more renewable penetration, the intermittency will make a greater impact on the electric power system.
As the batteries are still an evolving technology, the grid operators will increasingly resort to fossil-fuel-based “peaker” plants. These gas-fuelled peaker plants efficiently compensate for the intermittency of the variable renewable energy (VRE) sources. But if we want to achieve zero-carbon electricity, we must replace all greenhouse gas-emitting sources.
Adding up the costs
“We looked at all the peaker plants in California and we wanted to know the cost of electricity if we replaced them with hydrogen-fired turbines or with lithium-ion batteries.”, said Emre Gençer and Drake D. Hernandez, research scientists at MITEI. According to research supported by the MIT Energy Initiative (MITEI), hydrogen-fired power generation can be a cost-effective alternative to backing up solar and wind power.
The researchers used a core metric called the levelized cost of electricity (LCOE) as a way of comparing the costs of different technologies to each other. LCOE measures the average total cost of building and operating a particular energy-generating asset per unit of total electricity generated over the hypothetical lifetime of that asset.
Coming up with prices for replacing peaker plants with massive arrays of lithium-ion batteries was also relatively straightforward: “There are no technical limitations to lithium-ion, so you can build as many as you want; but they are super expensive in terms of their footprint for energy storage and the mining required to manufacture them,” says Gençer.
On the other hand, when the “battery” has so far dominated the electric vehicle market, with Tesla claiming more than 80 percent of EV sales in the U.S. and a number of other carmakers jumping on the battery bandwagon. But those believing in hydrogen have made substantial progress, too. Pheonix, Ariz.-based Nikola Motors went public earlier this year and is gearing up to roll out a hydrogen fuel cell-powered semi-truck and a pickup truck in 2021.
Coming back to the study, now comes the hard part: nailing down the costs of hydrogen-fired electricity generation. “The most difficult thing is finding cost assumptions for new technologies,” says Hernandez. Researchers had to conduct several lengthy conversations with equipment manufacturers and plant operators to reach any conclusion.
The team considered two different forms of hydrogen fuel to replace natural gas, one produced through electrolyzer facilities that convert water and electricity into hydrogen, and another that reforms natural gas, yielding hydrogen and carbon waste that can be captured to reduce emissions.
The researchers spent months compiling a giant dataset before setting out on the task of analysis. The results from their modeling were clear: “Hydrogen can be a more cost-effective alternative to lithium-ion batteries for peaking operations on a power grid,” says Hernandez.
Hydrogen alone will not usher in a zero-carbon future. But the research shows hydrogen needs to be seriously considered in the energy transition. The use of hydrogen for energy storage is an effective solution to solve the intermittent energy issues associated with solar and wind energy. The industry needs to identify key areas where hydrogen should be used and start making the massive investments necessary.
If renewable energy is to flourish and if the United States is to become carbon-neutral, all of the available zero-carbon technologies and platforms will be necessary.
