Mainspring
Series F in 2025
Mainspring Energy, Inc. is a technology company based in Menlo Park, California, that specializes in developing linear generator technology for low carbon, dispatchable energy solutions. Founded in 2010 by three Stanford engineers, the company focuses on creating advanced prototypes that convert fuel into electricity through a unique, low-temperature reaction of air and fuel. This innovative approach allows Mainspring to offer generators that provide affordable, reliable electricity while significantly reducing carbon emissions compared to traditional electric grids. The company's mission is to address climate change and enhance energy accessibility, contributing to the development of net-zero carbon energy systems for the future.
Fourier specializes in developing modular, automated hydrogen production systems designed for on-site deployment. This eliminates the need for hydrogen transportation, making it universally accessible. Their innovative architecture contributes to a sustainable energy future by providing green hydrogen for industries such as transportation and power storage.
Claros is a power management platform provider that utilizes cutting-edge hardware and software to enhance energy distribution and usage at data centers, thereby boosting compute performance and maximizing efficiency.
Tractian offers asset management and monitoring solutions. It provides tools for data collection and analysis to track asset performance and condition, integrating with sensors and devices for predictive maintenance. The company serves industries such as manufacturing, logistics, and energy.
Tractian offers asset management and monitoring solutions. It provides tools for data collection and analysis to track asset performance and condition, integrating with sensors and devices for predictive maintenance. The company serves industries such as manufacturing, logistics, and energy.
Charm Industrial
Series B in 2023
Charm Industrial develops carbon removal technology that converts agricultural residues into bio-oil via fast pyrolysis and injects the bio-oil into deep geological formations for permanent underground storage, enabling long-term carbon offsetting and contributing to climate change mitigation.
Gridco
Venture Round in 2016
Gridco Systems, established in 2010, specializes in innovative power distribution solutions tailored for modern electric grids. The company develops advanced power management systems that allow utilities to effectively manage the distribution of electricity. By utilizing cutting-edge power electronics and intelligent control systems, Gridco's technology enables real-time monitoring and management of voltage and other critical parameters within the distribution network. This approach enhances the predictability and precision of power distribution, addressing the evolving demands faced by electric power distribution system operators.
Gridco
Venture Round in 2014
Gridco Systems, established in 2010, specializes in innovative power distribution solutions tailored for modern electric grids. The company develops advanced power management systems that allow utilities to effectively manage the distribution of electricity. By utilizing cutting-edge power electronics and intelligent control systems, Gridco's technology enables real-time monitoring and management of voltage and other critical parameters within the distribution network. This approach enhances the predictability and precision of power distribution, addressing the evolving demands faced by electric power distribution system operators.
Gridco Systems, established in 2010, specializes in innovative power distribution solutions tailored for modern electric grids. The company develops advanced power management systems that allow utilities to effectively manage the distribution of electricity. By utilizing cutting-edge power electronics and intelligent control systems, Gridco's technology enables real-time monitoring and management of voltage and other critical parameters within the distribution network. This approach enhances the predictability and precision of power distribution, addressing the evolving demands faced by electric power distribution system operators.
Gridco Systems, established in 2010, specializes in innovative power distribution solutions tailored for modern electric grids. The company develops advanced power management systems that allow utilities to effectively manage the distribution of electricity. By utilizing cutting-edge power electronics and intelligent control systems, Gridco's technology enables real-time monitoring and management of voltage and other critical parameters within the distribution network. This approach enhances the predictability and precision of power distribution, addressing the evolving demands faced by electric power distribution system operators.
Gridco Systems, established in 2010, specializes in innovative power distribution solutions tailored for modern electric grids. The company develops advanced power management systems that allow utilities to effectively manage the distribution of electricity. By utilizing cutting-edge power electronics and intelligent control systems, Gridco's technology enables real-time monitoring and management of voltage and other critical parameters within the distribution network. This approach enhances the predictability and precision of power distribution, addressing the evolving demands faced by electric power distribution system operators.
SustainX
Venture Round in 2011
SustainX Inc. is a provider of grid-scale energy storage solutions, focusing on supporting electric grids and facilitating the integration of renewable energy sources. Founded in 2007, the company is based in Seabrook, New Hampshire, and specializes in energy storage technologies that enhance energy management for commercial and industrial applications. SustainX's innovative energy storage system employs a compressed air energy conversion process to store electrical energy, enabling efficient transmission asset utilization and optimization. The company's offerings also include ancillary services, peak power capacity, and cogeneration, all aimed at promoting a cleaner and more reliable electric grid. As of 2015, SustainX operates as a subsidiary of General Compression, Inc.
CLEAResult
Venture Round in 2011
CLEAResult specializes in energy management solutions, serving utilities, businesses, and individuals across various sectors. The company designs and implements energy transition programs, offering services such as energy optimization, benchmarking, research, and intelligence to help clients reduce energy usage, costs, and emissions.
Mascoma develops a consolidated bioprocessing platform to convert non-food biomass such as wood and switchgrass into cellulosic ethanol and biochemicals. It provides engineered microorganisms and proprietary CBP technology that combine enzyme production, hydrolysis, and fermentation into a single, streamlined workflow, enabling renewable fuel producers and industrial bioprocessors to access low-carbon ethanol and value-added biochemicals. The approach aims to simplify production, reduce costs, and accelerate scalable, sustainable alternatives to gasoline.
Mascoma develops a consolidated bioprocessing platform to convert non-food biomass such as wood and switchgrass into cellulosic ethanol and biochemicals. It provides engineered microorganisms and proprietary CBP technology that combine enzyme production, hydrolysis, and fermentation into a single, streamlined workflow, enabling renewable fuel producers and industrial bioprocessors to access low-carbon ethanol and value-added biochemicals. The approach aims to simplify production, reduce costs, and accelerate scalable, sustainable alternatives to gasoline.
Millennial Net
Series A in 2003
Millennial Net's flagship platform, MeshScape, offers highly scalable, low power, reliable wireless mesh networking capability that is beyond any conventional WSN technologies. Millennial Net also provides Wireless Energy Management and Energy Efficiency solutions focused on commercial and public building applications. Typically save 15%-30% of a buildings current energy consumption.