SustainX Closes $14.4M Round

SustainX, which is developing technology for energy storage using compressed air, has closed on $14.4 million in financing. GE Energy Financial Services, a unit of GE, contributed to the round, as did Cadent Energy Partners and existing shareholders Polaris Ventures and Rockport Capital. New Hampshire-based SustainX previously raised $5.4 million from investors including the Small Business Innovation Research program of the National Science Foundation and the Energy Storage Program of the US Department of Energy.

New Hampshire-based company SustainX has received $14.4 million from GE Energy Financial Services, a unit of GE (NYSE: GE), and other investors to continue developing its technology for energy storage using compressed air. Through the GE Ecomagination Challenge’s “Powering the Grid” program, in which SustainX is a partner, GE Energy Financial Services joins Cadent Energy Partners and prior investors Polaris Ventures and Rockport Capital in the new round of venture financing. The GE Ecomagination Challenge demonstrates GE’s global commitment to accelerate the development and deployment of innovative power-grid technologies through open collaboration, while providing financial support to develop and commercialize innovative technologies.

Details of the financing were not disclosed. A total of $5.4 million in earlier financing for SustainX came from the Small Business Innovation Research program of the National Science Foundation and from the Energy Storage Program of the US Department of Energy. AES Energy Storage, LLC is working with SustainX to demonstrate a full-size system in the field, capable of storing enough energy to power 1,000 typical US homes.

GE Energy Financial Services’ investment in SustainX reflects its commitment to enabling technology innovation by providing not only capital but technology evaluation and potential commercial opportunities with GE, particularly to develop a smarter power grid. The investment is based partly on GE Global Research’s evaluation of SustainX’s technology.

“GE’s backing, alongside that of other investors and the federal government, validates our efforts to develop and commercialize a cost-effective, grid-scale energy storage solution,” said Thomas Zarrella, CEO of SustainX. “We are on schedule to develop a grid-scale prototype to be demonstrated at an affiliated AES site where we can showcase our transformative energy storage technology.”

The present round of funding for SustainX represents the first time that both GE and Cadent Energy Partners have invested in the growing company. “We are pleased to be an investor in SustainX as we believe this company’s energy storage solution has a global market with enormous potential,” said Paul McDermott, Managing Partner of Cadent Energy Partners. McDermott continued, “SustainX has set a remarkable pace in developing its product and establishing joint ventures to aid in the commercial production of its energy storage units. We look forward to participating in its continued success.”

To store energy, SustainX compresses air by using electricity to drive pistons inside cylinders. The resulting high-pressure air is stored in above-ground vessels. To release energy later, the system uses stored air to drive the same pistons, which in turn drive an electric generator. SustainX technology keeps air at a nearly constant temperature during compression and expansion; this significantly improves efficiency and reduces the cost of compressed-air energy storage below that of other above-ground energy-storage options.

Independent experts estimate that the market for grid-scale energy storage will be $18 billion by 2015. Storage can improve the economics of wind and solar power, improve grid stability, store off-peak energy to be used during on-peak periods, improve the feasibility of microgrids in rural areas, and reduce emissions from the gas-turbine peaker plants presently used to keep electric supply precisely matched with demand.

About SustainX
SustainX was founded in 2007 by engineers at the Thayer School of Engineering at Dartmouth College. It has received funding from the National Science Foundation Small Business Innovation Research Program and the Energy Storage Program at the US Department of Energy, as well as equity investments from GE Energy Financial Services and top-tier venture investors Rockport Capital (with offices in Menlo Park, CA and Boston, MA), Polaris Venture Partners (Boston, MA and Seattle, WA), and Cadent Energy Partners (Stamford, CT and Houston, TX). SustainX is a General Electric Ecomagination Partner.

SustainX has received four US patents to date on core aspects of its technology, solidifying its leading IP position in the field of compressed-air energy storage. The issued patents are general enough to cover a wide range of isothermal systems, including both existing SustainX systems and those in development.

The company’s transformative energy storage technology, which it terms ICAES™ (for Isothermal Compressed-Air Energy Storage), uses no fuel. SustainX’s competitive advantages stem from its patented proprietary thermodynamic and hydraulic control innovations, a design centered on mature industrial components, and reliance on ambient-temperature, nontoxic working fluids.

SustainX ICAES is targeting the emerging market for bulk (grid-scale) energy storage being created by the growth in renewable generation, and aims to disrupt costly “peaker” plants that burn natural gas or other polluting fuels.

About GE Energy Financial Services
GE Energy Financial Services’ experts invest globally across the capital spectrum in essential, long-lived, and capital-intensive energy assets that meet the world’s energy needs. In addition to capital, GE Energy Financial Services offers the best of GE’s technical know-how, technology innovation, financial strength, and rigorous risk management. Based in Stamford, Connecticut, the GE business unit helps its customers and GE grow through new investments, strong partnerships, and optimization of its $21 billion in assets. For more information, visit

About GE
General Electric (NYSE: GE) is a diversified infrastructure, finance and media company taking on the world’s toughest challenges. From aircraft engines and power generation to financial services, health care solutions, and television programming, GE operates in more than 100 countries and employs about 300,000 people worldwide. For more information, visit

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