portable consumer electronics and other equipment.
Solatube International (Vista, CA)
Using proprietary technology, materials, and design, Solatube’s tubular skylights provide natural sunlight to interior spaces. The company was founded in Australia and established its worldwide headquarters in the San Diego area during a 1998 corporate restructuring.
Sunlight Direct (San Diego, CA)
Founded in 2004, Sunlight Direct has developed a proprietary system that tracks and concentrates solar energy for distributed power generation and efficient lighting.
Sustainable Green Technologies (Escondido, CA)
Sustainable Green Technologies, also known as SGT, is creating technology to use hydrogen as an alternative fuel. The company has four patents pending that cover commercial bio-hydrogen generation from waste-streams and enhanced green algal oil production.
Synthetic Genomics (San Diego, CA)
The startup founded in 2005 by human genome pioneer J. Craig Venter and Nobel laureate Hamilton Smith plans to genetically engineer new types of cells with desired properties for the production of bioenergy or substitutes for petrochemicals.
Tour Engine (San Diego, CA)
Tour Engine has developed a split-cycle design for an internal combustion engine that integrates temperature differential to operate more efficiently.
Trex Enterprises (San Diego, CA)
A technology incubator and government research contractor, Trex specializes in developing high-temperature advanced materials for possible use in alternative energy applications.
Ultraviolet Sciences (San Diego, CA)
This company founded in 2002 has developed proprietary water purification systems that use a compact and energy-efficient ultraviolet disinfection treatment systems for treating drinking water.
Verari Systems (San Diego, CA)
A data center equipment provider that has created a “green data center” concept that maximizes energy efficiency and reduces electricity costs by consolidating computing racks into a self-contained system.
Waterless (Vista, CA)
Waterless has developed proprietary “no-flush” urinals that consume no water, with a single urinal saving as much as 45,000 gallons of water a year.
YBR Solar (San Diego, CA)
This spinout from San Diego-based Quanlight is working to develop an unorthodox design for a power-generating solar cell that is 50 percent more efficient at converting sunlight to electricity than conventional solar technology.
ZuumCraft (San Diego, CA)
This company offers energy-efficient transportation—a three-wheel electric scooter powered by lithium batteries.
[Xconomy San Diego Editor Bruce V. Bigelow contributed to this report]