{{Short description|Coal-fired power station in Utah, US}} {{Use American English|date=July 2025}} {{Use mdy dates|date=December 2025}} {{Infobox power station | name = Intermountain Power Plant | name_official = | image = Intermountain Power Plant, Utah.jpg | image_caption = Aerial view of Intermountain Power Plant, Utah | image_alt = | location_map_caption = Location of the Intermountain Power Plant in Utah | coordinates = {{coord|39|30|27|N|112|34|49|W|type:landmark_region:US-UT|display=inline,title}} | coordinates_ref = | country = United States | location = Delta, Utah | status = O | construction_began = September 1981 | commissioned = June 1986 | decommissioned = | cost = US$4.5 billion | owner = Intermountain Power Agency | operator = Los Angeles Department of Water and Power (LADWP) | th_fuel_primary = Coal | th_fuel_tertiary = | ps_units_operational = 2 X 950 MW | ps_units_manu_model = GE<br />Babcock & Wilcox | th_cogeneration = | th_combined_cycle = | ps_electrical_capacity = 1,900 MW | ps_electrical_cap_fac = | website = }} '''Intermountain Power Plant''' is a large coal-fired power plant at Delta, Utah, US. It has an installed capacity of 1,900 MW, is owned by the Intermountain Power Agency, and is operated by the Los Angeles Department of Water and Power (LADWP).<ref name=nyt130611> {{cite news | title = E.P.A. Delays Rule on Power Plant Emissions | first1 = John M. | last1 = Broder | newspaper = The New York Times | date = 2011-06-13 | url = http://green.blogs.nytimes.com/2011/06/13/e-p-a-delays-rule-on-power-plant-emissions/ | accessdate = 2012-02-19}} </ref><ref name=powerengineering> {{cite news | title = Intermountain Generating Station | newspaper = Power Engineering | publisher = Pennwell Corporation | date = 2002-08-01 | url = http://www.power-eng.com/articles/print/volume-106/issue-8/departments/managing-the-plant/intermountain-generating-station.html | accessdate = 2012-02-19}} </ref><ref name=ipa>{{cite web | title = About Us | publisher = Intermountain Power Agency | url = http://www.intermountainpower.com/About_Us.html | accessdate = 2012-02-19 | archive-date = 2012-03-11 | archive-url = https://web.archive.org/web/20120311202552/http://www.intermountainpower.com/About_Us.html | url-status = dead }}</ref><ref>{{Cite web|url=https://www.latimes.com/business/la-fi-garcetti-dwp-gas-plants-20190212-story.html|title = How will L.A. Replace three gas plants that Mayor Eric Garcetti plans to shut down?|website = Los Angeles Times|date = 12 February 2019}}</ref> The plant includes a HVDC converter.<ref name="WuShockley1988">{{cite journal|last1=Wu|first1=C.T.|last2=Shockley|first2=P.R.|last3=Engstrom|first3=L.|title=The Intermountain Power Project 1600 MW HVDC transmission system|journal=IEEE Transactions on Power Delivery|volume=3|issue=3|year=1988|pages=1249–1256|issn=0885-8977|doi=10.1109/61.193910}}</ref> It is scheduled for replacement in 2025 with an 840 MW natural gas plant, designed to also burn green hydrogen.
== Description ==
The power plant consists of two units each with a generation capacity of 950 MW.<ref name=ipa/> Generating units are equipped with General Electric tandem compound steam turbines and Babcock & Wilcox subcritical boilers.<ref name=powerengineering/> The boiler houses of Intermountain Power Plant are {{convert|91.75|m}} tall and the flue gas stack is {{convert|213.67|m}} tall. The HVDC Intermountain transmission line runs between Intermountain Power Plant and Adelanto Converter Station in Adelanto, California.<ref name=powerengineering/>
== History ==
Construction on the plant began in September 1981. Commercial operation of unit 1 started in June 1986, and unit 2 in May 1987. The project cost US$4.5 billion.<ref name="miami201279">{{cite news|date=1979-12-20|title=Biggest Coal Power Plant Planned|newspaper=Miami News|url=https://news.google.com/newspapers?id=75NYAAAAIBAJ&sjid=RUMNAAAAIBAJ&pg=4862,4005086|archive-url=https://archive.today/20130124141007/http://news.google.com/newspapers?id=75NYAAAAIBAJ&sjid=RUMNAAAAIBAJ&pg=4862,4005086|url-status=dead|archive-date=January 24, 2013|accessdate=2012-02-19}}</ref><ref name=la100877> {{cite news | title = Utah Panel to Study Power Plant Impact | first1 = Bill | last1 = Stall | newspaper = Los Angeles Times | date = 1977-08-10 | url = https://pqasb.pqarchiver.com/latimes/access/650468182.html?dids=650468182:650468182&FMT=ABS&FMTS=ABS:AI&type=historic&date=Aug+10%2C+1977&author=&pub=Los+Angeles+Times&desc=Utah+Panel+to+Study+Power+Plant+Impact&pqatl=google | archive-url = https://archive.today/20130131163204/http://pqasb.pqarchiver.com/latimes/access/650468182.html?dids=650468182:650468182&FMT=ABS&FMTS=ABS:AI&type=historic&date=Aug+10,+1977&author=&pub=Los+Angeles+Times&desc=Utah+Panel+to+Study+Power+Plant+Impact&pqatl=google | url-status = dead | archive-date = January 31, 2013 | accessdate = 2012-02-19 | id = {{subscription required}}}} </ref> The plant was originally designed for four units; however, only two units were built.<ref name="industcards"> {{cite web|title=Coal-Fired Power Plants in Utah|url=http://www.industcards.com/st-coal-usa-ut.htm|archive-url=https://archive.today/20130126125730/http://www.industcards.com/st-coal-usa-ut.htm|url-status=usurped|archive-date=January 26, 2013|work=Industcards|accessdate=2012-02-19}} </ref> In 2004, units 1 and 2 were uprated.<ref name=industcards/> These works were conducted by GE and Alstom.<ref name=powerengineering/> The Intermountain Power Agency planned to build the third unit of 900 MW capacity. This unit was expected to go online in 2012; however, the project was cancelled after its major purchaser, the city of Los Angeles, decided to become coal-free by 2020.<ref name=nyt090709> {{cite news | title = Los Angeles' 'Coal Free' Vow Scuttles Utah Power-Plant Expansion | first1 = Robin | last1 = Bravender | newspaper = The New York Times | date = 2009-07-09 | url = https://www.nytimes.com/gwire/2009/07/09/09greenwire-los-angeles-coal-free-vow-scuttles-utah-power-29532.html | accessdate = 2012-02-19}} </ref><ref name=powerengineering030909> {{cite news | title = IPA scraps 900 MW coal-fired generating station | newspaper = Power Engineering | publisher = Pennwell Corporation | date = 2009-09-03 | url = http://www.power-eng.com/articles/2009/09/ipa-scraps-900-mw-coal-fired-generating-station.html | accessdate = 2012-02-19}} </ref>
On December 28, 2011, one of the generators failed causing the shut-down of one unit for several months.<ref name=deseret170212> {{cite news | title = 'Major' breakdown cripples IPP for 6 months | first = John | last = Hollenhorst | newspaper = Deseret News | date = 2012-02-17 | url = http://www.deseretnews.com/article/865550400/Major-breakdown-cripples-IPP-for-6-months.html | archive-url = https://web.archive.org/web/20120220072435/http://www.deseretnews.com/article/865550400/Major-breakdown-cripples-IPP-for-6-months.html | url-status = dead | archive-date = February 20, 2012 | accessdate = 2012-02-19}} </ref>
In 2025, LADWP stopped receiving power from the coal fired plant.<ref>{{Cite web |last=Smith |first=Hayley |date=2025-12-04 |title=Los Angeles says so long to coal |url=https://www.latimes.com/environment/story/2025-12-04/los-angeles-says-so-long-to-coal |website=Los Angeles Times |language=en-US}}</ref>
==Natural gas and green hydrogen plant plans== {{See also|Combined cycle hydrogen power plant}} By 2025 the plant is scheduled to be replaced with an 840 MW natural gas plant, at a cost of $865 million, which utility managers state is necessary both to avoid blackouts which could result from the non-dispatchable nature of solar and wind generation,<ref name=LAT_2019-12 >{{ cite news | url=https://www.latimes.com/environment/story/2019-12-10/los-angeles-hydrogen-fueled-intermountain-power-plant | title=Los Angeles wants to build a hydrogen-fueled power plant. It's never been done before | last=Roth | first=Sammy | newspaper=Los Angeles Times | date=2019-12-10 | access-date=2020-10-14 | quote=Utility staff told the board it’s critical to build an 840-megawatt gas-fired power plant to replace the coal-burning facility that DWP operates today. Without a traditional power plant, they said, the city might have trouble keeping the lights on when there’s insufficient electricity being generated by solar panels and wind turbines. }}</ref> and to ensure operation of the Path 27 HVDC transmission line which brings solar and wind power from Utah to Los Angeles.<ref name=LAT_2019-11 >{{ cite news | url=https://www.latimes.com/environment/story/2019-11-19/climate-change-activists-urge-los-angeles-not-to-build-new-gas-plant-in-utah | title=Climate change activists urge Los Angeles not to build a gas plant in Utah | last=Roth | first=Sammy | newspaper=Los Angeles Times | date=2019-11-19 | access-date=2020-10-14 | quote=The utility plans to replace Intermountain in part with an $865-million plant that runs on natural gas. ... LADWP officials claim that without a traditional power plant at Intermountain, they won’t have the physical ability to transport solar and wind energy through the transmission line to Los Angeles. They also say they hope to eventually fuel the gas plant with clean-burning hydrogen, although the technology is still being developed and could be prohibitively expensive. }}</ref><ref name=LADWP_newsletter >{{ cite web | url=http://www.ladwpintake.com/the-future-of-ipp-is-green/ | title=The Future of IPP Is Green - Transforming L.A.'s Last Coal Plant to Help Reach 100% Renewable Energy | last=Tucker | first=Carol | work=LADWP | date=21 April 2020 | access-date=2020-10-14 | quote=Engineering studies had determined that 840 MW was the minimum generation capacity needed to maintain sufficient voltage for the critical transmission systems to operate reliably. }}</ref>
The new natural gas fired turbines would be the first of their kind capable of burning a mix of 70% natural gas and 30% "green" hydrogen (hydrogen released by the electrolysis of water, using renewably generated electricity) when the plant opens in 2025.{{ r | LAT_2019-12 | p=1 | q=DWP leadership committed to installing turbines capable of burning a mix of 30% hydrogen and 70% gas when the new power plant opens in 2025. Under the timeline described Tuesday, that ratio would steadily change until the plant burns 100% hydrogen in 2045, the deadline set by state lawmakers for a 100% climate-friendly electricity supply. }} The plan is to steadily increase the hydrogen percentage to 100% by 2045, which will require upgrading or replacement of the turbines to be able to handle greater percentages of hydrogen.{{ r | LAT_2019-12 | p=1 | q=Those turbines would need to be upgraded or replaced over time as technology matures to allow higher levels of hydrogen burn — which is far from guaranteed. }} <ref name=UD_1 >{{ cite web | url=https://www.utilitydive.com/news/green-hydrogen-gets-real-as-utility-business-models-and-delivery-solutions/572412/ | title=Green hydrogen gets real as utility business models and delivery solutions emerge | last=Trabish | first=Herman | work=Industry Dive | date=2020-03-02 | access-date=2020-10-15 | quote=Mitsubishi has natural gas units in operation using blends of up to 90% hydrogen, Mitsubishi Marketing Vice President Todd Brezler told Utility Dive. The turbines it will bring to market "will be engineered to burn 30% hydrogen blends by 2025 and they will eventually be retrofitted to burn 100% hydrogen by basically swapping out combustion system parts during planned maintenances, at costs similar to replacing other parts." }}</ref> The project was granted a $504 million DOE loan in 2022.<ref>{{cite web |title=DOE loans office commits over US$600 million to Utah hydrogen hub & Louisiana graphite facility |url=https://www.energy-storage.news/doe-loans-office-commits-over-us600-million-to-utah-hydrogen-hub-louisiana-graphite-facility/ |website=Energy Storage News |date=27 April 2022}}</ref> One expert noted in 2019 that using hydrogen to replace natural gas in power-plant turbines was theoretical and had never been done in practice,{{ r | LAT_2019-12 | p=1 | q=Using renewable hydrogen to fuel natural gas turbines and generate electricity — as DWP has proposed — is “more of a theoretical” at this point, said Ben Gallagher, an expert in carbon and emerging technology at Wood Mackenzie. “There's not serious pilot projects that are underway that I'm aware of,” Gallagher said. }} and a LADWP IPP official stated that the "economics remain to be seen" and "could be quite expensive."{{ r | UD_1 | p=1 | q=As a first-of-its kind project, Intermountain's "economics remain to be seen" and "could be quite expensive," he [LADWP Intermountain Power Project Operating Agent Gregory Huynh] acknowledged. "But electrolyzer costs are coming down and more adoption could drive that faster, like it did with solar. Our goal is to be cost competitive, but we need steps like these to get there." }}
The first major (500 MW) hydrogen burning power plant in the US was expected to begin burning 5% hydrogen in Ohio in November 2021, and to migrate to 100% hydrogen over the next decade.<ref>{{cite news | url=https://www.spglobal.com/platts/en/market-insights/latest-news/electric-power/081221-first-major-us-hydrogen-burning-power-plant-nears-completion-in-ohio | title=First major US hydrogen-burning power plant nears completion in Ohio | last=Hering| first=Garrett | newspaper=S&P Global | date=2021-08-12 | access-date=2021-10-07 | quote=Several additional U.S. natural gas-hydrogen hybrid power projects are underway, the largest of which is the Intermountain Power Agency's planned conversion of an existing coal plant into an 840-MW combined-cycle gas facility by 2025 that would combust up to 30% hydrogen and gradually move to only green hydrogen. Most of the plant's output is under contract with the Los Angeles Department of Water and Power. }}</ref>
==Gallery== thumb|none|400px|Intermountain Power Plant thumb|Intermountain Power Plant, aerial, winter 2009|350px|none thumb|none|400px|Intermountain Power Plant with completed combined-cycle units post Coal Unit 1 shutdown,{{Citation needed|reason=EIA data as of August 2025 gives a September shutdown date|date=September 2025}} July 2025
==See also== * Hydrogen fuel cell power plant
== References == {{Reflist}}
Category:Coal-fired power stations in Utah Category:Buildings and structures in Millard County, Utah Category:Energy infrastructure completed in 1986 Category:Converter stations Category:1986 establishments in Utah