A new solar power system is easy to add to a roof, and performs its own safety checks.
By Kevin Bullis
Ordinarily, installing and connecting a new array of rooftop solar panels takes days, weeks, or even months because the hardware is complex and various permits are needed. Yesterday, on a frigid day in Charlestown, Massachusetts, researchers completed the process in about an hour.
Homeowners can install the system themselves, by gluing it to a rooftop. The permitting is handled by a combination of electronic sensors and software that communicates with local jurisdictions and utilities.
Installation and permit-related expenses currently account for more than half of the overall cost of a new solar power setup. “By simplifying the system so that it’s like installing an appliance, we envision that the soft cost will be virtually eliminated,” says Christian Hoepfner, director of the Fraunhofer Center for Sustainable Energy Systems, which developed the system. Doing so would lower the cost of a typical residential solar installation from $22,000 to as little as $7,500, he says.
“It’s impressive to see how quickly the installation went up,” Fouad Dagher, manager of new products and services at the utility National Grid, said after the demonstration. “It makes it easier for consumers and utilities.”
Solar power can be dangerous if not installed properly. Heavy components may be blown off a roof if not secured properly, and solar panels can produce potentially deadly voltages if not properly grounded, and every wire protected.
The Fraunhofer system uses light, flexible solar panels encased in durable plastics. The panels can be securely attached to a shingled roof via an adhesive backing that anchors the panels even in winds up to 110 miles per hour.
The solar panels use electrical equipment, developed by the startup VoltServer, that breaks DC power into discrete, addressed packets, something like the data packets sent over the Internet. If one of these packets fails to reach its destination—for example, if someone were to touch a damaged wire, the current is instantly cut off, preventing injury—a feat demonstrated by a brave EnerVolt employee at the Charlestown demonstration when he purposely touched an exposed wire on the new solar installation.
The whole system is connected to the grid via a plug similar those used for fast-charging electric cars, which can handle high voltages safely.
Once plugged in, the system performs several tests to ensure it’s safe. Hoepfner says the software probably does the job more consistently than inspectors would. Test information would be sent to the local utility for approval over the Web.
While all the hardware exists now, and will go on sale soon, the automated permitting still needs work. Fraunhofer had preapproved the system with the authorities, who’d had inspected the process ahead of time. Commercialization will require developing new standards for solar power systems.
Homes will also need preinstalled outlets designed for solar panels, similar to the high voltage dryer connections in new homes. For now, installing the outlet will require a trained electrician, though it can be done in just a couple of minutes via a device that can be quickly attached to a meter.
Meanwhile, testing is ongoing to make sure the adhesive will keep the solar panels anchored in very hot weather. Because the panels are flush with the roof, rather than mounted on racks that allow air to flow under them, they get hotter than conventional panels, which also lowers the amount of power they can produce.