It’s pie-in-the-sky by design, but a new report from DOE’s National Renewable Energy Laboratory on the technical potential of rooftop solar in the U.S. is eye-opening nonetheless. All told, NREL said, some 1,118 gigawatts (GW) of capacity could be installed if all the “suitable” rooftops in the U.S. were covered with PV panels, generating upward of 1,432 terawatt-hours (TWh) of electricity annually—roughly 39 percent of total annual electric sales.
NREL is quick to point out that the study, Rooftop Solar Photovoltaic Potential In The United States (which can be found here), did not look at economics. As such, the study represents “an upper bound on potential deployment rather than a prediction of actual deployment.” But even on this basis, the study found that solar’s potential has expanded significantly in the past decade: A similar study on solar PV’s technical potential that NREL completed in 2008 estimated that 664 GW of rooftop capacity could be installed, generating roughly 880 TWh of electricity annually. The difference between the two estimates, NREL wrote, “can be attributed to increases in module power density, improved estimation of building suitability, higher estimates of the total number of buildings, and improvements in PV performance simulation tools that previously tended to underestimate production.”
Taking that statement at face value, it is almost certain that PV’s technical potential is going to continue rising in the years to come. In particular, NREL noted that its analysis is based on an assumed module efficiency of 16 percent; a figure it used to better represent a mixture of installed systems, not just premium PV panels. If the analysis had assumed a module efficiency of 20 percent, which is where premium systems are today, “each of the technical potential estimates would increase by about 25 percent above the values stated in this report,” NREL wrote.
Continue reading New NREL Study:
For Rooftop PV In U.S.
The two events had nothing to do with one another, and yet they are inextricably linked. I am an inveterate coupon clipper and in the latest mailer from BJ’s Wholesale Club (my big box savings store of choice) I noticed an eye-popping deal on LEDs—8 60 watt-equivalent bulbs from Sylvania for $19.99, or roughly $2.50 apiece. The next day, GE announced that it planned to stop manufacturing compact fluorescent lamps (CFLs) and focus instead on LEDs.
The market never really took to CFLs, for understandable reasons noted in my household as well: Most of them could not be used with dimmer switches, they generally took a long time to “warm up” to their claimed light output and the light itself was harsh, like the traditional tubular fluorescents that CFLs evolved from and not the soft light of old-style incandescent bulbs. Still, they were significantly more efficient than traditional incandescent bulbs and sales climbed steadily. According to DOE data (see chart below), by 2014, just two years after federal rules took effect that essentially served as the death knell for incandescent bulbs, CFLs accounted for 46 percent of all installed A-type lamps (the screw-in variety that make up the bulk of installed residential lighting). But that clearly was the high-water mark for the twisted CFL.
Continue reading LEDs Clobber CFLs;
Turn Indoor Farming
Into New Growth Market
There was a news nugget in the American Wind Energy Association’s latest market report (released last week, the executive summary can be found here) that should be required reading for electric utility executives everywhere: Non-utility purchasers (that is, corporate and institutional customers) signed power purchase agreements (PPAs) for more than 1,300 megawatts of windpower in the fourth quarter of 2015—accounting for roughly 75 percent of the total.
Translation: Corporate America is going green and if you don’t give them what they want, they are going to get it on their own.
This transition has been under way for some time—Whole Foods, for example, said it planned to go all-in for windpower in 2006 and Walmart signed its first major windpower deal in 2008—but it wasn’t until 2013 that the change really began to take hold. Since then, it has been an entirely different story, almost an overnight transition from “meh” to “let’s do this.” According to data from RMI’s Business Renewables Center, corporate buyers signed power purchase agreements for more than three gigawatts of new wind and solar power in 2015, two and a half times the 1.2 GW of green power purchased in 2014. And this is just the beginning, says Hervé Touati, head of the BRC. “Despite this incredible success, less than 20 corporations have been active in this space since its inception. This is just a start….”
Continue reading Corporate Interest
In Green Energy
Requires New Thinking
From Electric Utilities