Asolar-thermal power project made up of mirrored pyramids, a super turbocharger and a blend of gases for solar cell manufacturing were just some of the technologies featured at the Dow Jones Alternative Energy Innovations south of San Francisco on Tuesday.

Here are some highlights:

VanDyne SuperTurbo
The Fort Collins, Colo.-based company, is seeking $15 million to work on the pre-production prototype that combines elements of a supercharger and a turbocharger to boost the engine's fuel efficiency.

Both the supercharger and a turbocharger force compressed air into a car's engine to improve performance. A supercharger is run by the crankshaft while a turbocharger relies on a turbine driven by the car's exhaust. The hybrid version that is being developed by VanDyne makes it possible to build a car with a gasoline engine that is 50 percent smaller than conventional engines but still provides the same horsepower, said company founder and CEO Ed VanDyne.

The technology could improve fuel efficiency by 30 percent for a passenger vehicle and up to 10 percent for a heavy truck. That translates into $700 in savings per year for each passenger car owner and $8,000 per year for the truck driver, VanDyne said.

Volkswagen has bought three prototype devices while John Deere has purchased one, VanDyne said. His company is due to deliver those components to Volkswagen and John Deere by year's end.

The company pitched its technology at the Cleantech Forum in Washington, D.C. last September, and said it was seeking $12 million. VanDyne CFO Greg Fuhrman said the company aims to raise $15 million instead to launch a commercial product in two years. The company's technology was developed inside Woodward Governor Co. (NSDQ: WGOV), a developer of engines, turbines and electrical power systems in Fort Collins, Colo.

Sixtron
This crystalline silicon solar cell maker has relied on silane gas as an anti-reflective coating. But silane is highly combustible and can cause fires and shut down factories – and it can get expensive. Sixtron, a Canadian startup, said it's developed an alternative that can work just as well without creating fire hazards and reduce manufacturing costs at the same time.

The company's solution comes with a gas-generating cabinet called SunBox in which three reactors turn cartridges of inert polymer powder into methyl silane gases for coating the cells, said Zbigniew Barwicz, Sixtron's CEO.  Cell makers could just plug in the system in their production lines. In fact, using the SunBox is cheaper than hooking up to the silane-producing equipment, which reduces the installation and operating costs by 50 percent Barwicz said.

Some of the top 10 solar cell makers are currently evaluating Sixtron's offerings, Barwicz said. He expects to see customers using SunBox on their production lines starting next year.

The company is raising $15 million in a Series B round and expects to close it by the third quarter of this year, said Bates Marshall, vice president of sales and marketing at Sixtron. The company has raised $11.5 million in venture capital, $2 million in debt financing and $1.6 million in government funds.

Sixtrom has contracted with a Boston company to make SunBox, and has formed a joint venture with a Chinese company to produce the polymer powder, said Marshall, who declined to name the partners. Sixtron plans to contract with gas and chemical companies to package the powder into cartridges, he added.

VirgoStar Solar
The most unusual presentation came from Lina Harriot, CEO of VirgoStar Solar, which is setting out to develop a solar thermal power technology that would stack thousands of mirrors into the shape of a pyramid.

Harriot started the Las Vegas-based company only last August and concedes that she has no experience in running a solar energy company. In fact, she didn't realize she was supposed to talk about her company's technology and business plan during her alloted time at the conference and spoke mostly about why harnessing the sun's energy is a good idea.

In an interview, she said she was an accountant for roughly 20 years and closed her business to pursue her interests in solar energy production last year. She put an ad on Craigslist to look for a mechanical engineer to join her firm, and hired James Barricke, who is pursuing a master's degree in mechanical engineering at the University of Nevada in Las Vegas.

Harriot said she came up with the idea of a pyramid-shaped system by reading about the pyramids built by the Egyptians and the Aztecs. The 30-foot to 40-foot tall system could be made up of four walls of mirrors (roughly 900 mirrors per wall) that resemble the shape of a terraced Aztec pyramid, a design that could better concentrate the sunlight to generate the heat necessary to produce electricity, she added. 

The mirrors would focus the light onto a collector that is located inside the pyramid to heat up the air to run a free-piston engine, which then drives a turbine to produce electricity, Harriot said. Using the free-piston engine would greatly reduce the need to use water, a precious resource in the hot Nevada desert, she added. The idea sounds like the Stirling engine design being used by some solar thermal power developers. Other types of technologies require heating up water or some types of fluids to generate the steam for power generation.

Harriot was able to raise $150,000 from a former customer at her accounting firm to pursue this new venture. She also invested $50,000 of her own money, and is looking to raise $1 million to continue the technology development.