NRG Energy keeps making waves—in energy. The energy supplier, which owns gigawatts of electric generation, including solar, wind, natural gas and coal facilities across the U.S., recently started going a lot smaller, offering residential solar photovoltaic installations through its subsidiary, NRG Residential Solar. Now it plans to offer PV systems with battery backups, allowing consumers to use their own energy during blackouts—or even at night. 

The new systems are being designed as pergolas, essentially easily deployable shade structures that can quickly start powering a home or small business.The systems can also be grid-tied. And, since they have all the other qualities and battery back-up, such systems could aid in disaster recovery from events, like Hurricane Sandy. 

Earlier this week, Forbes reported that NRG Solar plans to introduce residential solar arrays with battery backup under a partnership with GCL-Poly Energy and Sunora Energy Solutions. NRG Solar CEO Tom Doyle discussed the upcoming pergola PV systems with battery backup with Forbes in San Francisco. Such free-standing structures can be prefabricated offsite to help reduce the cost of the system. Something Doyle and NRG may be banking on. “I’m excited about using the solar pergola to penetrate the residential space,” Doyle tells Forbes. “There are a lot of residential solar companies out there, and I’m trying to figure out what are their stories, what we can bring to the market.” 

Solar leasing and power-purchase agreements, which allow homeowners to go solar without paying up-front costs, have exploded over the past few years, there aren’t many companies that offer such systems with batteries to go along with them, battery systems capable of powering a house remain cost-prohibitive. Currently, battery storage only makes sense for homes off the grid and far from transmission lines, and only a small handful of third-party ownership companies, like SolarCity, offer such options. 

While battery storage is still cost-prohibitive it has some advantages. For instance, grid-tied solar arrays have to shut off during a power outage—it’s a safety feature, because during power outage in the day a PV system operating by itself and not tied to the grid could produce too much energy for a home and fry appliances by providing too much energy. Plus during a blackout a PV system without a shut-off feeds electricity back to the grid, creating an electrocution hazard for workers trying to restore power. A system with battery backup can divert excess power to the batteries without shutting the system off.

Another advantage of such a system is that it can feed excess power back to grid in states like California, which have different electric rates based on time of use, potentially netting the home owner a higher rate for the power produced. Utilities must regulate the amount of energy on the grid on a minute-by-minute basis and clouds can quickly and dramatically affect the amount of electricity on the grid from solar, so NRG’s pergolas could help regulate all of that. A battery system can help assure the utility that the amount of electricity coming from the home or business is a more static energy source, rather than a wildly fluctuating one. 

Despite Doyle speaking about the pergolas with battery storage, the company hasn’t officially introduced the new service yet. “We are really in our infancy on the development of the pergolas and should have a lot more to communicate in the very near future,” explains NRG spokesperson Jeff Holland.

That could be as soon as the end of this month. Forbes reports that the company plans to show the system at a conference in Southern California in late-April.

The original article was posted on the SolarReviews blog.