LATHAM, N.Y.-- Plug Power Inc., a leading provider of turnkey hydrogen solutions for the global green hydrogen economy, announced it will discuss the new partnership and including software collaboration with Energy Vault Holdings, Inc. at its analyst day in Rochester on June 14th. Energy Vault has designed and will integrate for the city of Calistoga, a hybrid microgrid system that includes an 8 MW (megawatts) hydrogen fuel cell stationary power for the first of its kind hybrid microgrid (battery plus green hydrogen) that will be used during times of wildfires and other emergencies. This will be the largest planned hydrogen powered fuel cell installation in the United States. The California Public Utility Commission (CPUC) requires that state utility grid operators shut off power during severe weather to help prevent wildfires. Energy Vault designed a carbon free solution combining a small portion of short duration batteries to support black start and grid forming requirements with green hydrogen-fed fuel cells for 48 hour+ storage duration to eliminate the need for PG&E to rent mobile diesel generators to provide backup power in Calistoga during these Public Safety Power Shutoff (PSPS) events. For the ultra-long duration need and multi-day discharge, Energy Vault chose Plug’s PEM (proton exchange membrane) fuel cells as it can offer cleaner, more operationally flexible, and more cost-effective power to the microgrid. The power from the new microgrid will be dispatched and optimized by Vault-OS, the technology neutral energy management digital platform developed by Energy Vault. “Our agreement with Energy Vault marks a huge step forward for hydrogen fuel cells in the microgrid market and represents the future of utility power back-up,” said Andy Marsh, CEO of Plug. “Green hydrogen is uniquely positioned to solve the need for clean long-duration energy storage in at-risk communities like Calistoga that are susceptible to power interruptions. Energy Vault’s unique energy storage integration platform, for short, long, and multi-day duration, has facilitated the adoption of our hydrogen powered fuel cells and minimized the overall cost of the microgrid, making possible the final approval by the CPUC. We are excited to begin deeper collaboration with Energy Vault with this first and largest utility scale energy storage system using green hydrogen and fuel cells while leveraging their Vault-OS digital platform to optimize the dispatch economics of our fuel cells for our customers.” “We are excited to partner with Plug Power, leader in the hydrogen fuel cell industry, in the deployment of carbon free solutions that have been accelerated in market adoption and deployment through our digital integration platform” said Marco Terruzzin, Chief Commercial and Product Officer of Energy Vault. “Working closely with the city of Calistoga stakeholders, PG&E and Plug Power we are delivering a “best fit-least cost” solution for the growing Public Safety Power Shutoff problem.” Energy Vault previously announced it is building a community microgrid for Pacific Gas and Electric Company (PG&E) to provide Calistoga with a minimum of 293 megawatt-hours (MWh) of dispatchable carbon-free energy during planned outages and PSPS events. The microgrid will integrate a short duration battery system with a long duration storage system of fuel cells and green liquid hydrogen. Plug’s fuel cell technology will serve as the microgrid’s stationary backup power generator. The energy storage system will be owned, operated, and maintained by Energy Vault while providing dispatchable power under a long-term tolling agreement with PG&E. Plug will deliver 8 MW of fuel cell power, made up of 40-foot ISO containers. The fuel cells will be manufactured in the US, primarily at Plug’s gigafactory in Rochester, New York, and assembled and tested at Vista Technology Park, Plug’s world-class fuel cell manufacturing facility in Slingerlands, New York. This production approach will allow Energy Vault to take advantage of the additional 10% ITC available under the IRA for American-made content. Construction of the energy storage system in Calistoga is anticipated to begin in the fourth quarter of 2023 with commercial operation expected by the second quarter of 2024. For more information on Plug’s stationary power fuel cell, visit https://www.plugpower.com/learn-more-about-plugs-stationary-power-products/.

About Plug

Plug is building an end-to-end green hydrogen ecosystem, from production, storage and delivery to energy generation, to help its customers meet their business goals and decarbonize the economy. In creating the first commercially viable market for hydrogen fuel cell technology, the company has deployed more than 60,000 fuel cell systems and over 185 fueling stations, more than anyone else in the world, and is the largest buyer of liquid hydrogen. With plans to build and operate a green hydrogen highway across North America and Europe, Plug is building a state-of-the-art Gigafactory to produce electrolyzers and fuel cells and multiple green hydrogen production plants that will yield 500 tons of liquid green hydrogen daily by 2025. Plug will deliver its green hydrogen solutions directly to its customers and through joint venture partners into multiple environments, including material handling, e-mobility, power generation, and industrial applications. Plug Power Safe Harbor Statement This communication contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 that involve significant risks and uncertainties about Plug Power Inc. (“PLUG”), including but not limited to statements about: Plug’s plan to supply 8MW of hydrogen fuel cell stationary power, delivering clean energy to the City of Calistoga, during times of wildfires and other emergencies during Public Safety Power Shutoff events. This being the largest planned hydrogen powered fuel cell installation in the United States; Plug’s PEM fuel cells offering cleaner, more operationally flexible and more cost-effective power to the microgrid as compared to mobile diesel generators; Plug’s fuel cell technology serving as PG&E’s community microgrid’s stationary backup power generator; Energy Vault being able to take advantage of the additional 10% ITC available under the IRA for American-made content; Construction begins in the fourth quarter of 2023 with commercial operation expected by the second quarter of 2024. Such statements are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in these statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to the business of PLUG in general, see PLUG’s public filings with the Securities and Exchange Commission (the “SEC”), including the “Risk Factors” section of PLUG’s Annual Report on Form 10-K for the year ended December 31, 2022 and any subsequent filings with the SEC. Readers are cautioned not to place undue reliance on these forward-looking statements. The forward-looking statements are made as of the date hereof, and PLUG undertakes no obligation to update such statements as a result of new information. MEDIA CONTACT Caitlin Coffee Allison+Partners plugPR@allisonpr.com SOURCE: Plug Power, Inc.

Energy Vault Selects Plug Power to Supply 8 Mw of Hydrogen Fuel Cells as Part of Hybrid Microgrid Back-Up System for Pg&E and the City of Calistoga