Tag Archives: NREL

New NREL Study:
 Prodigious Potential
 For Rooftop PV In U.S.

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:
 Prodigious Potential
 For Rooftop PV In U.S.

Green Power Is The Key
 For Utilities To Keep
 Their Commercial Clients

For utility executives used to 40-year planning horizons, the past 10 years have been, shall we say, a difficult learning experience.

Ten years ago shale gas production was still at miniscule levels and natural gas prices were well above $6 per million British thermal units (mmBtu) and showing no signs of decline; today gas is the go-to fuel and price projections have essentially flat-lined well under $5 per mmBtu. Ten years ago nuclear was in the midst of a renaissance, with utilities considering plans to build upward of 28 new reactors; today just four new reactors are being built (by two utilities) and they are way over budget and long-delayed. Ten years ago renewables were a far-off hope, with EIA’s 2005 energy outlook pegging solar PV at 0.00 quads through the 2025 forecast horizon; today solar is shining, with 20 gigawatts of installed capacity to date and much more on the way, while wind accounts for more than 4 percent of the nation’s electric generation.

Another change in the past 10 years, harder to quantify but just as real, has been the complete shift in customer expectations. Previously, customers simply bought what their utilities offered—“We don’t have any of that clean power today, you’ll have to buy this brown stuff.” Today, customers are going out and finding the cleaner, greener power they want—a fact I see regularly in press release after press release touting company X’s decision to buy the output from a new solar or wind project or, even more telling, to develop the project themselves.

It has been hard to put numbers on this change, but a new report from DOE’s National Renewable Energy Laboratory (Renewable Electricity Use by the U.S. Information and Communication Technology (ICT) Industry, which can be found here) provides clear evidence of the shift within the information/telecommunications sector. Ten years ago, the companies in an EPA initiative called the Greenhouse Power Partnership purchased essentially zero renewable energy; today, those companies (the number participating has now climbed to 68) purchase 7.8 million megawatt-hours (mwh) of green power—amounting to almost 44 percent of their total electricity consumption in 2014.


Taking a broader slice of the ICT market, NREL tracked 113 companies that reported information either through EPA’s GPP or another program called the Carbon Disclosure Project Worldwide and estimated overall electricity use in the sector at more than 59 million mwh in 2014. Of this total, which is well over 1 percent of annual U.S. electric consumption, 8.3 million mwh—or about 14 percent—was renewable. According to NREL, the green electricity is sourced from a mix of power purchase agreements (PPAs), on-site generation, utility green power products and renewable energy certificates (RECs). In other words, in large part, the companies are going out and getting what they want, not waiting for their supplier to bring it to them.

This growth is almost certain to continue in the years ahead, NREL said, projecting that by 2020 the amount of renewable energy used by the 113 will more than double, climbing to at least 18.5 million mwh even under a low growth scenario. In a more aggressive estimate, NREL said renewable consumption by the 113 could shoot up to more than 37 million mwh.

And some of the firms have even grander plans. Amazon, Apple, Facebook and Google, for example, all have publicly announced corporate plans to purchase 100 percent of their electricity from green sources. That won’t happen overnight, but don’t be surprised if 10 years from now they have met that goal.

These commercial customers clearly are driving huge changes in the utility industry—it’s time, past time in fact, for the industry to respond and give them what they want or risk losing them as customers entirely.

–Dennis Wamsted