Skip to Content

Companies to Watch: Private Companies

August 18, 2009

Company: Nanosolar
Year founded: 2002
Funding Raised/Sources: $401.5 million
Benchmark Capital, Mohr Davidow Ventures, EDF, AES

Although thin-film solar cells are far less efficient than traditional silicon cells, they could be a lot cheaper to make. Nanosolar has developed an ink made from nanoparticles that allows solar panels to be printed on metal foil by the roll. Its factory in California and a panel assembly facility near Berlin are expected to begin large-scale production later this year.

Company: Tendril
Year founded: 2004
Funding Raised/Sources: $50 million
VantagePoint Venture Partners, Good Energies, RRE Ventures, Vista Ventures, Appian Ventures

Smart-grid technology is designed to give utilities and customers real-time information about energy usage; utilities can use this information to respond more effectively to variations in supply and demand. Tendril makes outlets and thermostats that allow appliances and heating and cooling systems to be controlled through a Web interface. For example, air conditioners could be turned off during times of peak demand.

Company:1366 Technologies
Year founded: 2007
Funding Raised/Sources:
$12.4 million
North Bridge Venture Partners, Polaris Venture Partners

Hopes to combine a number of incremental design and manufacturing innovations in multicrystalline-­silicon solar cells, with a goal of making solar competitive with coal by 2012.The company’s first advance was a grooved ribbon that reflects more light onto the surface of the cell, improving efficiency by 2 percent. The company has also modified the cell’s architecture to improve efficiency even further while keeping production costs constant.

Company: Deepwater Wind
Year founded: 2005
Funding Raised/Sources:
D.E. Shaw

Is trying to move wind turbines further offshore, using “jacket” support structures from the oil and gas drilling industry that are less costly than steel foundations. The company hopes to have America’s first offshore wind farm running off Rhode Island by 2012.

Company: Solyndra
Year founded: 2005
Funding Raised/Sources:
More than $600 million
U.S. Venture Partners, Redpoint Ventures, Virgin Green Fund

Hopes to corner the rooftop-photovoltaic market with panels composed of rows of cylindrical thin-film solar cells. These can absorb sunlight from all angles and are cheaper to install than conventional flat panels. The company has a U.S. Department of Energy loan guarantee for half a billion dollars, which will be used to build a manufacturing facility to churn out enough solar panels each year to generate 500 megawatts.

Company: A123
Year founded: 2001
Funding Raised/Sources:
More than $250 million
GE, Alliance Capital, Motorola, Qualcomm, North Bridge Venture Partners, Sequoia Capital, CMEA Ventures

A leader in developing and manufacturing lithium-ion batteries for use in electric vehicles, the company also produces multimegawatt battery units used to stabilize the electrical grid and store energy produced during off-peak hours for use when demand spikes.

Company: BrightSource Energy
Year founded: 2006
Funding Raised/Sources:
More than $160 million
VantagePoint Venture Partners, Morgan Stanley, Black River, Google, Draper Fisher Jurvetson, BP, DBL Investors

Has contracts to supply 2.6 gigawatts of electricity to utilities using its solar thermal technology. Each solar plant will use tens of thousands of mirrors to concentrate the sun’s rays on a central tower to boil water that will generate steam to turn a turbine. A 410-megawatt facility in Ivanpah, CA, the company’s first, is expected to be in operation by 2012, with other farms in development throughout the Southwest.

Company: Silver Spring Networks
Year founded: 2002
Funding Raised/Sources:
Foundation Capital, Kleiner Perkins Caufield and Byers

Makes network equipment for consumer smart-grid technologies, such as smart meters, that are easier for utilities to incorporate. Its system communicates wirelessly, using standard Internet protocols.

Company: AltaRock
Year founded: 2007
Funding Raised/Sources:
$30 million
Google, Khosla Ventures, Kleiner Perkins Caufield and Byers

Is trying to create new sites for geothermal plants by fracturing the hot, dry bedrock present everywhere underneath the earth’s surface and then feeding cold water into the fractures to retrieve the heat. The technique can create small earthquakes, however; a DOE safety study could derail the company’s demonstration project in Northern California.

Company: Stirling Energy Systems
Year founded: 1996
Funding Raised/Sources:
$100 million

Uses large, mirrored parabolic dishes to concentrate light driving a stirling engine located at the dish’s focus. The engine converts thermal energy directly to mechanical energy to turn a generator. The company has contracts to produce nearly a gigawatt of power for the California grid in the coming years.

Keep Reading

Most Popular

It’s time to retire the term “user”

The proliferation of AI means we need a new word.

Sam Altman says helpful agents are poised to become AI’s killer function

Open AI’s CEO says we won’t need new hardware or lots more training data to get there.

An AI startup made a hyperrealistic deepfake of me that’s so good it’s scary

Synthesia's new technology is impressive but raises big questions about a world where we increasingly can’t tell what’s real.

Taking AI to the next level in manufacturing

Reducing data, talent, and organizational barriers to achieve scale.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at with a list of newsletters you’d like to receive.