Generac Holdings Inc. designs, manufactures, and distributes various energy technology products and solution worldwide. The company offers residential automatic standby generators, automatic transfer switch, air-cooled engine residential standby generators, and liquid-cooled engine generators; Mobile Link, a remote monitoring system for home standby generators; residential storage solution, which consists of a system of batteries, an inverter, photovoltaic optimizers, power electronic controls, and other components; smart home solutions, such as smart thermostats and a suite of home monitoring products. It also provides smart home energy management devices and sensors for heating and cooling system; smart doorbell cameras; and portable and inverter generators; multiple portable battery solutions; manual transfer switches; outdoor power equipment, including trimmers, field and brush mowers, log splitters, stump grinders, chipper shredders, lawn and leaf vacuums, and pressure washers and water pumps; and battery-powered turf care products. In addition, the company offers commercial and industrial products comprising cleaner-burning natural gas fueled generators; light-commercial standby generators and related transfer switches; stationary generators; single-engine industrial generators; industrial standby generators; industrial transfer switches; light towers, mobile generators, commercial mobile pumps, heaters, dust-suppression equipment, and mobile energy storage systems; stationary energy storage system and related inverter products; and aftermarket service parts and product accessories. The company distributes its products through independent residential dealers, industrial distributors and dealers, national and regional retailers, e-commerce partners, electrical/HVAC/solar wholesalers, solar installers, catalogs, equipment rental companies, and other equipment distributors; and directly to end users. The company was founded in 1959 and is headquartered in Waukesha, Wisconsin.

Bloom Energy Corporation designs, manufactures, sells, and installs solid-oxide fuel cell systems for on-site power generation in the United States and internationally. The company offers Bloom Energy Server, a solid oxide technology that converts fuel, such as natural gas, biogas, hydrogen, or a blend of these fuels into electricity through an electrochemical process without combustion. It sells its products through direct and indirect sales channels to utilities, data centers, agriculture, retail, hospitals, higher education, biotech, and manufacturing industries. The company was formerly known as Ion America Corp. and changed its name to Bloom Energy Corporation in 2006. Bloom Energy Corporation was incorporated in 2001 and is headquartered in San Jose, California.

Ballard Power Systems Inc. engages in the design, development, manufacture, sale, and service of proton exchange membrane (PEM) fuel cell products. The company offers its products for power product comprising for bus, truck, rail, marine, stationary, and emerging market, such as material handling, off-road, and other applications. It also engages in the delivery of services, including technology solutions, after sales services, and training; and provision of engineering services, product and systems integration services, and related technology transfer for a variety of PEM fuel cell applications. It operates in the United States, Germany, Canada, China, Poland, the United Kingdom, the Netherlands, France, Denmark, Belgium, India, Taiwan, Spain, Norway, Australia, Japan, and internationally. The company has a strategic alliance with Linamar Corporation for the co-development and sale of fuel cell powertrains and components for class 1 and 2 vehicles in North America and Europe. Ballard Power Systems Inc. was founded in 1979 and is headquartered in Burnaby, Canada.

FuelCell Energy, Inc., together with its subsidiaries, manufactures and sells stationary fuel cell and electrolysis platforms that decarbonize power and produce hydrogen. The company provides various configurations and applications of its platform, including on-site power, utility grid support, and microgrid, as well as distributed hydrogen; solid oxide-based electrolysis; solutions for long duration hydrogen-based energy storage and electrolysis technology; and carbon capture, separation, and utilization systems. It also offers technology to produce electricity, heat, hydrogen, and water. In addition, the company provides turn-key solutions, including development, engineering, procurement, construction, interconnection, and operation services. It serves various markets, including utilities and independent power producers, industrial and process applications, education and health care, data centers and communication, wastewater treatment, government, commercial and hospitality, microgrids, manufacturing, industrial hydrogen, port, oil and gas, wind and solar projects, food and beverage, hydrogen for mobility and material handling, and hydrogen fuel for heat, as well as engineering, procurement, and construction firms. The company primarily operates in the United States, South Korea, and Europe. FuelCell Energy, Inc. was founded in 1969 and is headquartered in Danbury, Connecticut.

OPAL Fuels Inc., together with its subsidiaries, engages in the production and distribution of renewable natural gas for use as a vehicle fuel for heavy and medium-duty trucking fleets. It also designs, develops, constructs, operates, and services fueling stations for trucking fleets that use natural gas to displace diesel as transportation fuel. In addition, it offers design, development, and construction services for hydrogen fueling stations. Further, the company engages in the generation and sale of renewable power to utilities. OPAL Fuels Inc. is based in White Plains, New York.

Fusion Fuel Green PLC, together with its subsidiaries, manufactures and sells miniaturized PEM electrolyzers to produce green hydrogen in Portugal, Spain, and rest of southern Europe. The company offers HEVO-Chain, a centralized PEM electrolyzer; and HEVO-Solar, a grid-independent hydrogen generator. It also provides engineering and procurement services comprising advisory, concept and proposal developments; FEL I, II and III studies; construction and legalization services; and operation and maintenance services. In addition, the company is involved in hydrogen project development. It serves natural gas networks and grids, oil refineries, ammonia producers, regulators, and related government departments. Fusion Fuel Green PLC was founded in 2018 and is based in Dublin, Ireland.

Advent Technologies Holdings, Inc., an advanced materials and technology development company, operates in the fuel cell and hydrogen technology markets in North America, Europe, and Asia. It develops, manufactures, and assembles fuel cell systems and critical components that determine the performance of hydrogen fuel cells and other energy systems. The company offers high-temperature proton exchange membrane (HT-PEM) fuel cells; and electrodes for applications in the fuel cell and energy storage markets, as well as membrane electrode assemblies. It is also involved in the design of fuel cell stacks for stationary power, portable power, automotive, aviation, energy storage and sensor markets. The company is headquartered in Livermore, California.

Polar Power, Inc. designs, manufactures, and sells direct current (DC) power generators, renewable energy, and cooling systems in the United States and internationally. The company offers DC base power systems, DC hybrid power systems, DC solar hybrid power systems, and mobile power systems. Its DC power systems are available in diesel, natural gas, LPG/propane, and renewable fuel formats. It serves customers in the telecommunications, military, commercial, industrial, and marine markets. In addition, the company sells its products through a direct sales force, and independent service providers and dealers. The company was formerly known as Polar Products, Inc. and changed its name to Polar Power, Inc. in October 1991. Polar Power, Inc. was incorporated in 1979 and is based in Gardena, California.