The technology group Wartsila is delivering a 500 MW & 2 GW hour portfolio of energy storage systems to clean energy developer and operator Clearway Energy Group. The contracts cover five sites located in Hawaii and California and include one of the world’s largest ever solar-plus-storage project portfolios. The combination of energy storage and solar photovoltaic resources will provide essential grid reliability to balance an increasing mix of renewable generation.The Wärtsilä and Clearway projects demonstrate the vital role that solar and storage will play in delivering these targets, and accelerating the transition, by creating low-cost clean energy at scale.The portfolio includes the Daggett 2 and Daggett 3 projects, which taken together represent one of the largest co-located photovoltaic plus storage facilities in California, at 482 MWac of solar PV and 275 MWac / 1.1 GWh of energy storage. The Daggett projects are in San Bernardino, California, adjacent to the site of a retired coal and natural gas plant. The AC-coupled energy storage systems will deliver renewable energy during increasingly volatile peak periods and help the state reach its goal of 100 percent carbon-free electricity by 2045. The order for Daggett 3 was booked to Wärtsilä order intake in Q3 2021, and the order for Daggett 2 was booked in Q4 2021. Construction has commenced on both projects with expected completion dates in 2023.Two projects, comprising 75 MWac / 300 MWh (megawatt hour) of energy storage, are being installed at Clearway Energy Group’s Mililani I Solar and Waiawa Solar Power facilities on the Island of Oahu in Hawaii. The addition of energy storage will help Clearway Energy Group ensure reliable delivery of sustainable energy and contribute to Hawaii’s goal of reaching 100 percent renewable energy generation by 2045. The orders for Mililani I Solar and Waiawa Solar Power were booked to Wärtsilä order intake in Q1 2021, and construction is expected to finalise in 2022. The projects are Wärtsilä’s first large-scale energy storage systems in Hawaii.The fifth project in the portfolio is a 147 MWac / 588 MWh energy storage system that will be connected to the operating 192 MWac Rosamond Central solar PV facility in Kern County, California. The energy storage system will increase the effectiveness of the solar facility by performing ancillary services, primarily solar shifting, for the California Independent System Operator. The order was booked to Wärtsilä order intake in July 2022 and construction is expected to be completed in December 2023.Each facility will include Wärtsilä’s GridSolv Quantum, a fully integrated, modular and compact energy storage system, as well as the GEMS Digital Energy Platform, Wärtsilä’s sophisticated energy management platform for power system optimisation. All five projects will also include long-term Service+ GAP agreements with Wärtsilä, thus guaranteeing capacity and providing maintenance with performance guarantees for the lifecycle of the energy storage systems.