In September 2018, then California Governor Jerry Brown signed a bill that had just been passed by the state’s legislature. Senate Bill 100, California Renewables Portfolio Standard Program: Emissions of Greenhouse Gases, made it “the policy of the state that eligible renewable energy resources and zero-carbon resources supply 100% of retail sales of electricity to California end-use customers and 100% of electricity procured to serve all state agencies by December 31, 2045.” In other words, a 100% fossil-free electric grid within 27 years. An article in the on-line news source Vox captured the importance of the moment: California is “the most significant political jurisdiction in the world to take that step, by a wide margin. (It is the world’s fifth-largest economy!)”
Sometimes grand undertakings start slowly. Sometimes action occurs only when the framework of the future runs into the tangible circumstances of the present. This is the case for the Los Angeles Department of Water and Power (LADWP), the municipal utility that provides electricity and water to the City of Los Angeles. Last month the agency stated that it is working on a plan to bring hydrogen into its mix of electricity generation fuels. It is doing so because it is nearing the end of a long-standing power purchase agreement for electricity generated from coal, and it needs to configure itself for compliance with the strictures of SB 100.
The story starts in the 1970s when LADWP was anticipating a decade of healthy growth in electricity demand. (In the event, the growth rate throughout the 1980s exceeded 5% per year.) The agency, already accustomed to looking beyond its borders for new sources of power, entered into an agreement with the Intermountain Power Agency (IPA) as the largest offtaker from a coal-fired generating station that the IPA would build in the Utah desert. To bring the power to its service territory, LADWP and five neighboring municipal utilities would build a transmission line to cover the 500 miles (800 km) between Utah and southern California. Construction on the Intermountain Power Plant (IPP) started in 1981. The first generating unit went on line in 1986. Its twin started up in 1987. At that time, it was the largest coal-fired power plant in the United States. (Its current generating capacity after being “uprated” in 2004 is 1,900 MW.)
Fast forward to 2006, when California’s state legislature passed a generating efficiency mandate. In the words of a 2013 LADWP press release, the state’s electric utilities were prohibited from importing power that “exceeds a fossil fuel emissions cap after their current contracts expire. The emissions cap is set at the level of an efficient, combined cycle natural gas power plant.” In 2009 LADWP withdrew its support for a third generating unit at the IPP facility, saying it planned to be “coal free” by 2020. In 2013, the agency announced that it would “completely transition out of coal power from the Intermountain Power Plant … by 2025 at the latest, with efforts to begin that transition no later than 2020.” The agency said the transition would include construction on the IPP site of “a smaller natural gas plant that complies with California emission standards.” An LADWP official at the time referred to the initiative, and its effect of reducing “emissions by over 2/3” as “a home run.”
Fast forward again to the present. What looked like a home run in 2013 has now acquired a different cast. In December 2019, the Los Angeles Times began a story on recent developments for LADWP’s IPP project with this sentence: “As Los Angeles weans itself off the last of its coal-generated electricity, the city needs to replace that fuel with a climate-polluting natural gas plant in Utah, Los Angeles Department of Water and Power staff insisted Tuesday.” The story went on to report, though, that LADWP “pledged the facility would eventually burn renewable hydrogen instead of natural gas – something that has never been done before.” The agency’s plan calls for the capability to burn a fuel mixture composed of 30% hydrogen and 70% natural gas when the new plant opens in 2025. According to an article in the on-line trade journal Utility Dive, “the turbines on this plant will be capable of hydrogen-mixing on day one, and will incrementally make up more of the plant’s fuel mix, being capable of up to 40% from 2031-2035, 50% through 2040 and 75% until its 100% by 2045 benchmark.”
Whereas hydrogen occupies center stage in most of the reporting on the recent LADWP developments, the true heroes of the story are Utah’s solar and wind resources. Utility Dive states that the IPP plant is already “interconnected to 370 MW of wind, with 1,500 MW more under discussion, [and] 2,300 MW of solar in the queue.” Solar and wind mean intermittency of generation, and hydrogen is proposed as the energy storage medium that will allow firm electricity supply. The IPP situation appears in fact to represent a near-perfect-case scenario for hydrogen as an energy vector. Utility Dive reports that the IPP plant “sits directly above an underground salt dome that would be able to store high pressure hydrogen … for up to a year, allowing for more seasonal dispatch …” Contributing to the perfection are the characteristics of the transmission line. It is a 500 kV direct current line with a capacity of 2,400 MW, meaning it can transmit electricity from Utah to California with minimal line losses, and it has room for growth.
LADWP is thus positioned to create its share of the sustainable energy economy over the next 25 years, and it is now committed to hydrogen. In fact, according to LADWP’s General Manager Marty Adams, “there is no way to get to 100% renewable energy that I can see right now without hydrogen in the mix.” Undoubtedly the agency’s plans will grow and evolve as it continues its journey. Realization of its hydrogen vision will be contingent on the advance of technology. The Los Angeles Times reports that the agency is in contact with the main manufacturers of utility-scale gas turbines: Mitsubishi Hitachi Power Systems (MHPS), Siemens, and General Electric. All three have major hydrogen turbine development programs. MHPS has an active ammonia turbine development program. Siemens is also working in the ammonia branch of the field. We should stay tuned to this channel.