Two Companies’ Two Different ‘Hybrid Solar’ Methods for Creating Power
Solar power isn’t new, but two companies, both based in California, are putting a fairly new twist: They’ve developed “hybrid solar power” systems, which basically collect, harness and pump electricity and gather usable heat.
EchoFirst started its hybrid solar process about four years ago, and it works primarily on residential homes. The other company, called Cogenra, has a similar technology for commercial and industrial buildings, while also taking hybrid solar a step further: It is not only converting heat but also looking to expand into solar cooling and electricity.
Both companies are backed by the same venture capitalist, interestingly enough: Vinod Khosla of Khosla Ventures.
Talking with top brass at the two companies, they have similar themes but very different goals.
“I don’t consider Cogenra a rival,” says Gord Handelsman, chief marketing officer of EchoFirst. “The platform they use is fundamentally different, but there’s room for both of us in the solar market, for sure.”
Founded four years ago by Handelsman and Josh Plaisted, EchoFirst’s hybrid solar system is now sold across the country.
The first primary problem with traditional solar panels is that they generally have 15 percent efficiency in harnessing the sun’s energy. According to Handelsman, Plaisted came up with the idea of utilizing a mechanical blower to draw air under the photovoltaic modules and instead of the modules getting hot, the air gets hot. This is different from other solar companies that capture energy as water.
“In a regular PV (photovoltaic) system, you’d have solar panels on the roof and an inverter,” Handelsman says. “And you’d have a water tank and pumps from a water tank to a solar panel. In our hybrid system, the mechanical blower is a piece in the middle (of the panel), between a basic PV system on the roof and a basic solar water heating system. So now the molecules (from the sun) go to this little box.”
A demo of EchoFirst’s system can be seen here.
Handelsman says the U.S. Department of Energy contributed about $1 million to EchoFirst at the beginning of its research and development, and testing of the system took around three years. EchoFirst now sells its system to two primary markets: new home builders who are building a community from scratch and have to complete a whole slew of new rooftops, and individual home builders who want to retrofit their homes to make it more environmentally friendly.
While prices of solar systems have begun to go down, the cost of the hybrid solar system is still high; Handelsman says the cost ranges from $15,000 for smaller installations to $40,000 for bigger homes.
But he says the hybrid solar process “absolutely leads to more cost savings, because you’re harnessing and using a much higher percentage of the solar energy.”
Meanwhile, Cogenra is taking a different approach to hybrid solar power. Mani Thothadri, senior director of marketing, explains that Cogenra, a two-year-old company, only completed its first research and development pilot project in December 2010 in Sonoma, Calif.
Cogenra mounts PV cells on water pipes in the center of mirrors shaped like troughs. The one-axis parabolic troughs can be mounted on the roof of a building in any direction, and it tracks the sun. It’s a parabolic mirror that concentrates the sun’s energy by a factor of 10, and the mirror “bonds” the sun for 15 percent more energy.
The rest of the energy is conducted as heat, and is producing electricity. Water heats up as it passes from one row of modules to the other end and into a glycol water solution.
“The water may start at 80 degrees Fahrenheit, and then if you run it through the channels that are now extruded in the substrate, it goes up to 160 degrees,” Thothadri says. “We can harness 60 percent more solar energy with this procedure plus the 15 percent we were already getting from the sun to add up to 75 percent of the possible solar energy available.”
The temperature can be varied, according to the application; water for sterilization is hotter than water you’d use to take a shower, for example.
Thothadri says that with the success of its pilot project in Sonoma, Cogenra built its first commercial installation last month at General Hydroponics, also in Sonoma; it uses 36 modules for a capacity of 75 kilowatts.
Cogenra has approximately 30 active projects in five countries, with 20 of those finished.
But beyond hybrid solar, Cogenra is applying the technology to cooling, among other things.
“We increase the heat to 200 [degrees] Fahrenheit, and the heat is used to fire an absorption chiller,” Thothadri explains. “The heat now forms a thermal chiller, and that thermal chiller can now create air-conditioning.”
ABC News covered SoCalGas, a utility company in California, and its new pilot “solar cogeneration” system, found here.
Cogenra is in the early stages of offering the solar cogeneration system. The pilot project at SoCalGas, if successful, would be a major innovation, as the idea of solar cooling — especially in areas of the world that get extremely hot during the summer — represents an environmental and economic breakthrough.
Thothadri also says that Cogenra is in the early stages of electricity generation through hybrid solar, as well. “We want to be able to use this low-grade heat and convert it into electricity,” he says. “We’d like to extract the waste heat from the electricity, and store that for future use.”