CATALINA ISLAND REPOWER OPTIONSAugust 2020Southern California Edison provides electric, water and gas service to Catalina Island and its 4,100 yearround residents, its commercial and industrial customers and its 1 million annual visitors. Powering theisland, located 22 miles off the coast of Los Angeles, is a challenge that SCE has met since 1962.The island’s electricity is primarily generated by six diesel generators supplemented by propane-fueledmicroturbines. A pioneering battery energy storage system that has been in place since 2012 providesbalance. All current island generation emanates from the 11.9-megawatt Pebbly Beach GeneratingStation, located one mile from the center of Catalina’s primary population center, the city of Avalon.Five of the current diesel generators do not meet South Coast Air Quality Management District (SCAQMD)2018 emissions standards, which were implemented to improve air quality by reducing nitrogen oxide(NOx) emissions, and SCE has determined that refurbishment would not be feasible. Therefore, SCE willneed to replace Catalina’s current generation system within the next three to four years.This has provided SCE with an opportunity to evaluate long-term strategies to improve air quality andincrease the use of renewable energy, in keeping with the company’s Pathway 2045 strategy. To providea quantitative analysis of approaches to repower the island, SCE commissioned “Santa Catalina IslandRepower Feasibility Study,” a detailed technical and economic analysis, authored by consulting groupNV5 in partnership with the National Renewable Energy Laboratory and U.S. Environmental ProtectionAgency. The analysis uses a techno-economic model to assess the leading repower options and provideactionable information, including cost, schedule and benefits and challenges of each option.Looking at life cycle and capital costs, land availability, environmental sensitivities and other areas of risk,the analysis evaluates three general categories of emissions-compliant options: 100% emissions-compliant, fossil-fuel generation (diesel, propane and liquefied natural gas) Renewable energy and energy storage (at varying penetration levels) Undersea power cable to the mainland gridFor reliability purposes, every option includes at least some fossil generation, in some cases switching fromprime to backup source over time.The estimated life cycle costsfor the projects range fromapproximately 168 million to 458 million. The life cycle costincludes estimates for initialcapital costs and operationsand maintenance costs,including fuel, over a 30-yearperiod. Implementation timesvary from two to eight years.Separately, the analysis alsoexamined the potential toreduce energy usage on theisland using energy efficiency anddemand response measures.

FOSSIL-FUEL GENERATIONDiesel generation: Since the 1920s, dieselgenerators have been the primary sourceof power on the island, using diesel fueldelivered by barge. The six current generatorswere put into service from the 1950s to the1990s.The analysis evaluated two diesel replacementoptions, both of which would replace the fivenoncompliant generators with diesel enginesthat meet the new emissions standards: Option 1: replace five diesel generatorsbefore a regulatory deadline of Jan. 1,2024. Option 2: replace two of the existinggenerators by Jan. 1, 2023, and replacethe three remaining noncompliantgenerators by Jan. 1, 2027. Replacing justtwo generators now could enable greaterflexibility to add more renewable energyand energy storage in the future.Because fossil-fuel generation is required asbackup for all other options, these emissionscompliant diesel generators could function aspart of the long-term energy mix, even as thatenergy mix might become more renewableover time.Propane: SCE currently uses propane formicroturbines and delivers propane toAvalon residents for heating and cookingvia an on-island distribution system (thepropane is barged to the island from themainland). However, quickly replacing alldiesel generators with propane generatorswould be challenging and costly becauseof site limitations, the need for new off-sitefuel storage capacity and fire protectionrequirements. Future or phased conversionof some diesel generators to propane maybe a feasible option to further reduce NOxemissions.2Liquefied natural gas (LNG): LNGinfrastructure would be more costly incomparison to diesel or propane becausethere is no LNG infrastructure on the island.Moreover, facilities could not likely bepermitted and built in time to meet the firstNOx reduction target deadline.

RENEWABLE ENERGYSolar power paired withbattery energy storage: Solarand energy storage at somepenetration levels could offer apractical cost-effective option.Renewable energy and energystorage technologies arebecoming more technologicallyadvanced and economical overtime and additional renewableand energy storage projectscould be phased in as obstaclessuch as cost and footprint arereduced.One challenge to highpenetration solar on Catalina isthat some of the larger plots ofland that are suitable for solar/energy storage developmentare not near Avalon. Whilesome amount of solar plusstorage might be installedwithout significant distributionupgrades, high levels of solarcould significantly increasedistribution upgrade costs.(Upgrade costs were figured intothis analysis.) Fully 88% of theland on the island is set aside forpreservation and recreationalopportunities, potentiallylimiting availability for solardevelopment.For all solar scenarios, power flowcontrol, environmental permittingand further interconnectionanalysis would be required.Southern California Edison, August 20203

Solar panels at the USC Wrigley Institute for Environmental Studies, near Two Harbors. Credit: Karl Huggins/USC DornsifeSolar/energy storage was further modeled atvarious penetration levels, including: 100% Solar/Energy Storage: Goingall-renewable today would requireapproximately 280 acres of land. Giventhe complexity of this land use, there isno timing estimate associated with thisoption. This option would also require avery large energy storage system and, likethe other options, would require backupfossil-fuel generation equal to 100%of the load to meet SCE redundancyrequirements. The fossil-fuel generationsystem could be permitted and built first,in order to meet SCAQMD deadlines. 60% Solar/Energy Storage: With similarconstraints as the 100% renewableoption, 60% solar/energy storage is alsoan expensive option. And, as with otheroptions, the fossil-fuel generation systemcould be permitted and built first, in orderto meet SCAQMD deadlines. 5% Solar/Energy Storage: This scenariowas identified by the model used inthe analysis as the least-cost option forgeneration on Catalina. It also has the4advantage of being a steppingstone topotential wider deployment of renewableenergy on the island. This option couldpotentially be permitted and built inunder three years, could supplement thediesel generator strategy and could beextended out in future years to includean increased percentage of renewables— either the example 60% modeledin this analysis or a different thresholddepending on actual costs.Other renewable generation options:Additional renewables evaluated include windturbines, wave power and other emergingtechnologies. Wind power was not foundto be cost-effective on Catalina due to lowwind speeds and high capital costs. Costswould have to be reduced by 75% to makethis a viable option. Wave power is in earlierstages of technology readiness and doesnot currently appear cost-effective as asolar/energy storage alternative. It could beconsidered for a small-scale pilot projector future reevaluation as the technologydevelops and costs reduce.

UNDERSEA CABLEConnecting Catalina Island’s power supplywith the mainland via an undersea cablewas studied in 2004-2005. The currentanalysis is based on these previous studiesthat used a 35.5-mile route originating inHuntington Beach. The undersea cable wouldenable Catalina Island to be connected tothe increasingly clean generation mix on themainland. However, the cost of this projectmakes it one of the most expensive options.The undersea cable would require extensivepermitting from 11 federal, state andlocal agencies, looking at the extent ofenvironmental risks to underwater terrain,species and other resources, some of whichmight require mitigation measures. Permittingcomplexity is one of the factors leading to aproject execution period of almost five years.The cost includes the need for a backupemission-compliant, fossil-fuel generationsystem on Catalina to ensure power if thecable were to be damaged in an earthquake,accident or other failure. The backup systemwould have to be permitted and built inparallel, in order to meet SCAQMD deadlines.An alternate approach would be to build twoundersea cables, but this would add to costsand would not meet SCAQMD deadlines.ENERGY EFFICIENCYAND DEMAND RESPONSE“Santa Catalina Island Repower FeasibilityStudy” also includes a preliminary analysis ofopportunities to reduce the overall electricload on the island through energy efficiencyand demand-response programs. (This partof the analysis was hampered by the globalpandemic starting in March 2020.)Early estimates suggest total electricityconsumption could be reduced byapproximately 21% via cost-effectiveinvestments in energy-efficiencyimprovements. However, this does notinclude many factors including inflation,revenue from customers and the value ofpeak load reduction.While energy efficiency can reduce currentelectricity consumption, new development orother new electricity uses such as building,transportation or cruise ship electrificationwould increase total electric load over time.Southern California Edison, August 20205

SUMMARYThere are challenges to implementing anysource of electricity generation on Catalina,given its remoteness from mainlandinfrastructure, environmental sensitivities,land ownership structure and higher costfactors for completing projects on the island.However, there is no “do-nothing” optionavailable, as the current diesel generatorsmeet neither SCAQMD nor SCE’s clean airgoals.Among the options available are near-termsolutions that will provide safe and reliableelectricity while reducing overall emissionsand allowing for future clean energy planning.As SCE moves to meet its Pathway 2045vision, these options will allow flexibility tointegrate more renewable sources of energyin the medium and long term.6For more information and to read“Santa Catalina Island RepowerFeasibility Study,” more information on SCE’sclean energy vision,

Southern California Edison provides electric, water and gas service to Catalina Island and its 4,100 year-round residents, its commercial and industrial customers and its 1 million annual visitors. Powering the island, located 22 miles off the coast of