As has been the trend for several years, companies focused on energy efficiency technologies lead, and the once-dominating solar sector has a lighter presence than in years past.
Other leading industry sectors are agriculture and forestry, water and wastewater, recycling and waste, smart grid and transportation. Emerging categories are geothermal and companies with technologies that clean up conventional fuels.
More than 5,800 companies from 60 countries were nominated, and although most of top 100 are from the U.S. (56), there are 32 from Europe, six from Asia and one from South America.
Cleantech Group compiles the list with input from a 90-member expert panel of investors and corporations including 3M, ABB, BP, Ecolab, GE, General Motors and IBM.
Some of the top 100 companies are household names for people who follow the field: Sungevity and Clean Power Finance in solar leasing, Chargepoint in electric vehicle charging, Recyclebank in recycling, Elevance Renewable Science in green chemistry, Next Step Living in energy retrofits and Project Frog in green building.
The emphasis on energy efficiency technologies "has a strong link to investors' distinct preferences today for business models that more closely resemble those of traditional capital -- lighter and faster-to-market, tech and software start-ups -- proven money-winners of the past," said Richard Youngman, who created and leads the Global Cleantech 100 program.
In energy efficiency, "the biggest change over recent years has been the rise of data-centric and so-called 'cleanweb' companies, which span categories such as agriculture, recycling and transportation, as well as the more obvious energy areas such as lighting and buildings," he said.
Nest, which makes home thermostats that can learn patterns and preferences, was named "Company of the Year" in North America. Other regional companies of the year are Organica Water in Europe and Israel, and Hydrexia in Asia Pacific.
Ambri, a developer of an all-liquid metal battery technology for grid-scale energy, was named "Rising Star of the Year." Alphabet Energy, developing a low-cost waste heat technology, was named "Early Stage Company of the Year."
LanzaTech was honored for "Continued Excellence." Its process captures industrial waste gases such as carbon and converts them into new products.
Companies in the energy efficiency category include:
Next Step Living