Most solar panels are strung together like Christmas tree lights, so that if one panel stops working, performs poorly or ends up in the shade, the whole string is affected. To address this problem, 2-year-old startup eIQ Energy came out of stealth mode Monday night and announced it has raised $10 million in funding from NGEN Partners and Robert Bosch Venture Capital, for a system that helps connect solar panels in parallel instead of in a series. The San Jose, Calif.-based company says its Parallux system can make solar systems both cheaper to install and more efficient.
The system connects each individual panel to a high-voltage DC-to-DC power converter, which harvests the electricity from each panel and turns it into the ideal voltage for the inverter. An inverter (used for all solar systems) then converts the DC power into AC power used by household appliances more efficiently and more reliably. CEO Oliver Janssen tells us that this architecture can maximize the power from each panel and boost the total energy harvested by 5-30 percent.
The company says the system also enables installers to connect far more panels – more than 100 in some cases, compared to the typical four or five – with a single cable, which reduces installation costs, said Janssen. And because Parallux harvests power off of individual panels, developers don’t have to match all the panels and can more easily replace panels, reducing the overall cost of design and installation of a project.
While Parallux can enhance any solar-power system, it can yield the biggest advantage with thin-film projects, because thin-film panels have lower conversion efficiencies than crystalline panels, meaning that you need more panels to get the same-sized system. Using Parallux, developers can even combine crystalline and thin-film panels, Janssen said.
eIQ plans to initially target new residential and small commercial projects (2 MW and smaller), starting in California and then expanding within the United States. The company says it already has a 10-kW solar-power system on its own rooftop since last year and plans to install several beta projects of up to 100 kW each this year.
eIQ is just one of a number of startups and large solar firms that are focusing on ways to better connect solar panels in parallel instead of in a series. National Semiconductor has developed a similar technology called SolarMagic, which optimizes the power of each panel individually and achieves similar effects. Solar inverter company Satcon earlier this year also announced an energy management system, called Satcon Solstice, which uses a DC-to-DC converter and enables different types of panels, including crystalline and thin-film panels, to work together well. But Satcon is targeting is different market, focusing on large utility-scale systems, and the converter operates at the string level, rather than connecting to each panel.