LADWP will oversee the transformation of a coal-fired power plant to one that will run on “green” hydrogen — hydrogen produced using renewable energy. The project achieved a major milestone recently with the announcement that Mitsubishi Hitachi Power Systems (MHPS), had been awarded the contract to manufacture and service the turbines for the updated plant.
The turbines are the most important ingredient in the project’s success. When they are put into operation in 2025, they will generate electricity using a mix of 30 percent hydrogen and 70 percent natural gas. By 2045, when all necessary plant retrofits are completed, MHPS will be able to upgrade them so they can be powered entirely by hydrogen.
As the first project of its size, “it is an important milestone to establish the feasibility” of hydrogen production at this scale, said Thomas Koch Blank, a senior principal for industry and heavy transport at the Rocky Mountain Institute. “It will provide proof of concept of a type of hybrid plant — gas/hydrogen — that might play an important role for the power grid.”
All-In on Renewables
LADWP provides electricity to an estimated 1.5 million customers in Los Angeles, and another 5,000 in the Owens Valley. Its customer base is only slightly smaller than that of the Puerto Rico Electric Power Authority and about 30 percent bigger than that of the Long Island Power Authority. While L.A.’s population has been growing at slower rate in recent years, the city is expected to have about 3.5 million more residents by 2050.In April of 2019, Los Angeles Mayor Eric Garcetti announced a sustainable city plan that included a commitment to 100 percent renewable power by 2045. This would put the city on target for the statewide goal mandated by SB 100, signed by then-Gov. Jerry Brown in 2018.
The state law requires that “100 percent of retail sales of electricity to California end-use customers and 100 percent of electricity procured to serve all state agencies” be zero-carbon by the end of 2045. (Nuclear power is included in this mix; while “zero-carbon,” it’s generally not considered “renewable” because there is a finite supply of uranium.)
LADWP’s project is a significant step toward this goal and would help ensure that one in 10 Californians have reliable renewable power. It also offers a case study in how a local government can utilize and reimagine existing resources to make the most of them.
A Power Puzzle
Since 1978, LADWP has used electricity generated at a coal-fired power plant in Utah, which exists within a somewhat complicated ecosystem. The plant is known as the Intermountain Power Project (IPP), which is owned by the Intermountain Power Agency (IPA), a political subdivision of the Utah state government created under its interlocal cooperation act and owned by 23 Utah municipalities.IPP is operated by these municipalities in partnership with other participants, including LADWP, the California cities of Glendale, Burbank, Pasadena, Riverside and Anaheim and several Utah rural cooperatives.
“The way it worked out in the end is that the costs of the project are born by whoever is using the power,” said IPA spokesman John Ward. “Over the history of the project, greater than 98 percent of the total power billings have been paid by California municipalities.”
LADWP is the biggest customer, currently using almost half of the power produced at IPP. Reflecting this, LADWP directs the Intermountain Power Service Corp. (IPSC), which contracted with IPA to hire and manage the workers who operate and maintain IPP. Because of the way these relationships evolved, LADWP had an outsized ability to reimagine how IPP could fit in its plans for the future. According to Ward, it spent eight years doing just that.
Escaping from Coal
LADWP gets 18 percent of its power from coal, significantly higher than the 3.3 percent in California’s statewide energy mix. In a state aiming for a carbon free economy, a coal-fired power plant is high on the “not to do” list.Not only is coal a primary source of CO2 emissions, it also no longer makes economic sense as a power source. Estimates show that as soon as 2030 it will be cheaper to build renewable power sources than to run coal plants.
“IPA knew that the customers for those coal units were going to go away in 2025,” said Ward.
The plan that came into focus for renewing IPP had the potential to do two things. In the short run, the plant could be weaned entirely off coal and run on a mix of hydrogen and natural gas.
By 2045, it could not only be entirely powered by hydrogen but could also address the biggest challenge of renewable power generation: maintaining a steady balance between energy production and energy demand.
It’s All About the Battery
In California, generating renewable energy is not a stumbling block. “We're actually over-producing renewables so much that we have to shut down carbon-free renewable energy because the grid just can't handle it, said Mike Ducker, vice president, ofRenewable Fuels and Western Region for MHPS. “The demand is not a match with when the supply is available.”“We have days where we're able to use 85 percent renewables, but we also have peak summer days where we're at 15 percent,” said Reiko Kerr, senior assistant general manager of Power System Engineering, Planning and Technical Services for LADWP.
“How do you scale up that 15 percent to 100 percent without having this massive amount of over-generation built?” she said. “You don't need that during your spring and fall time, but you need it during the summer peak season.”
It’s long been known that the way to solve this problem is to store sun and wind power when it’s abundant and tap it when it’s not. “Right now, it's four-hour storage,” said Kerr of current battery capabilities. “If you double your storage footprint you get eight hours, but the density of that and the amount you would require would be massive. You could probably get through a day, but you need something that provides resiliency for long-term outages.”
While batteries are expected to eventually be able to store enough electricity to ensure that renewable power is “always on,” LADWP is plotting a course that does not depend on advancements in battery technology. Hydrogen can both power the generation of electricity and be stored in large quantities for long periods, and be used as needed.
Unique Geology
IPP happens to be situated in a place uniquely suited to hydrogen storage. It sits on top of a salt dome roughly three miles wide and one mile deep, with space for 100 enormous caverns in which hydrogen can be stored.This form of storage is well established. “For roughly 40 years, we've been storing hydrogen in salt caverns in the Gulf Coast to support the petrochemical industry,” said Ducker.
Solar and sun power production that would otherwise be shut down will be used to power electrolysis, a process that breaks water into hydrogen and oxygen. The hydrogen will be stored in a cavern and be available to power IPP’s new turbines.
“Depending on the size of the plant and how big we make the caverns, it can be anywhere from a week to several weeks’ worth of storage,” said Ducker.
Setting the Pace for Future Efforts
Though the LADWP project is the first of its kind, the innovation driving it is not new technology but a combination of existing methods on an unprecedented scale. It will provide certainty that when the power available from other renewable sources cannot meet demand, stored hydrogen can fuel enough generation to meet customer’s needs.“This is not a science fair experiment -- all of the elements of this project are mature technologies and are known technologies,” said IPA’s Ward. “We're just integrating and scaling them up.”
RMI’s Koch believes the project can be a catalyst for other green hydrogen efforts in the region. The updated IPP plant will provide hydrogen power “at scale which can kick-start the local hydrogen market,” he said, setting the pace for the development of hydrogen energy resources for other sectors, such as transportation.
“If there's an opportunity and probability of converting a gas plant into a hydrogen plant where you have greenhouse gas-free energy and it helps keep our grid reliable as we integrate large-volume intermittent renewable resources,” said Kerr of LADWP, “I don't see what the downside is.”
