Even taking into account transmission limitations, the western U.S. power grid could take on more than 70 percent wind and solar energy while still matching loads, according to researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory.

That’s a lot higher than the 20 percent top end utility types general cite. Transmission problems related to the variability of renewable energy like wind and solar – as opposed to the steady/on-demand nature of electricity from fossil plants – is considered a major clean-energy roadblock.

The key to blowing past the 20 percent barrier, says Victor Diakov, PhD, an NREL senior strategic analyst, is to exploit the immense, diverse geography of the western continental United States to create a self-balancing portfolio of wind and solar resources. Previous work has come to similar conclusion; the difference here is the NREL team modeled the possibilities of renewables in the West using new, fine-grained wind and solar data from across the region.

Diakov presented the lab’s results at the World Renewable Energy Forum in Denver; they had been published, in part, the prior week in the journal Wind Energy. He said the point of the study was “to try and fit in as much wind and PV as possible and still match the load.”

The team used data from 2004-2006; for wind, the input data came from the Western Wind and Solar Integration Study, which included three years of generation information from 32,000 potential 30-megawatt wind sites in the western United States. For solar, the used National Solar Radiation Data Base information for 250 western sites with a hypothetical capacity of 1,000 megawatts each.

Optimal wind site locations with (above) and without (below) transmission limitations. Red symbols represent selected sites, blue symbols – sites that are not selected for best load matching. With no transmission limitaitons, the turbines make more sense at the edges of the region, the model found. (Courtesy Victor Diakov/NREL)

Diakov and colleagues considered scenarios with and without large-scale transmission limitations. With no limitations, 80 percent of the West’s power load could be covered by wind and solar, with the balance from dispatchable sources like natural gas plants.

Adding in transmission constraints such as power and flow limits among the West’s 35 transmission regions, the percentage of wind and solar power drops – but not much, the NREL team found: dispatchable power still only accounted for 28 percent of total generation – meaning more than 70 percent of western electricity demand could, even with today’s transmission lines, could be sated by the wind and sun.

“So the numbers with transmission limitations don’t change much,” Diakov said. “That’s the major conclusion of the study.”

What does change is the distribution of what solar and wind resources would be built out. Under a real-world scenario, you’d have more wind at the geographic margins, the model found, maximizing geographic diversity.

Realizing a 70-percent-wind-and-solar vision would take more than PhDs and fancy computer models, of course. We’re talking about adding an enormous number of wind turbines and solar panels – 159 gigawatts of wind capacity and 123 gigawatts of solar. Today, the United States has a total installed capacity of 49 gigawatts of wind and 4 gigawatts of solar. But as wind and solar costs continue to fall and generation costs vis-à-vis fossil sources become a wash, the grid threatens to become the bottleneck. This study says indicates that it doesn’t have to be. 

The solar industry was divided Thursday in the wake the U.S. Commerce Department’s announcement that it would levy tariffs ranging from 31 percent to as high as 250 percent on Chinese-made solar panels, which the government says have been dumped on the U.S. market below production cost.

The split response makes sense: solar module prices have plunged, putting pressure on American photovoltaic manufacturers even as installation services providers, solar-financing companies and makers of mounts and other elements have seen booming business with the explosive growth low panel prices have engendered. Other manufacturers — even those directly hurt by panel prices the U.S. government has declared to be artificially low — worry how China’s reaction may impact their business and free trade in general.

Some reactions:

“Commerce’s ruling in the SolarWorld case is a bellwether decision,” added Steve Ostrenga, chief executive officer of Helios in a statement by the Coalition for American Solar manufacturing. “It underscores the importance of domestic manufacturing to the U.S. economy and will help determine whether the country will be a global competitor in clean technologies or outsource them China. It is also critically important for thousands of U.S. workers.”

“Today, SolarWorld and the many industry players who embrace the sustainable efficiency gains and price declines that come from fair competition can take heart that the U.S. government is standing up against Big China Solar,” said Gordon Brinser, president of SolarWorld Industries America Inc. and leader of the Coalition for Solar Manufacturing (CASM), in his own statement. “Commerce’s careful measures could help thwart China’s illegal drive to control the solar market and supplant manufacturers and jobs in America, the very country that invented, pioneered and innovated solar to today’s mainstream viability.”

“For the many former employees of at least 12 solar producers that have staged layoffs, shuttered plants or entered bankruptcies since 2010, it may be too late. But today’s announcement gives rise to the possibility that domestic solar manufacturing, environmentally sustainable solar production and robust global competition might one day soon return to boosting U.S. manufacturing, jobs and energy security.”

On the other hand, a group of manufacturers opposed to the tariffs under the banner of  the Coalition for Affordable Solar Energy issued their own statement. Among the reactions:

Robert D. Hansen, president and CEO, Dow Corning Corporation: “Dow Corning and Hemlock Semiconductor are among the world’s leading suppliers of polysilicon and other key solar materials that power solar innovation. We believe that the trade case brought against Chinese solar manufacturers by SolarWorld could undermine the solar industry’s significant progress at the very moment it is poised for success. It’s important to remember that no nation or industry “wins” when trade disputes escalate – and in this case, we are concerned about serious unintended consequences such as local job loss and retaliatory tariffs against the U.S.”

Tom Gutierrez, CEO of GT Advanced Technologies: “Ultimately, the protectionism that SolarWorld is encouraging fosters dependence and high-cost business models, rather than the agile approaches that are most successful in global competition. Now is the time for the U.S. solar industry to move forward with creating American jobs and enhancing our energy security. We are proof that American solar manufacturing can compete without special protections.”

Tore Torvund, CEO of REC Silicon: “Tariffs are not in the best interest of American solar manufacturing, the American solar industry, or American solar consumers. We are concerned about the increased likelihood that China will retaliate with their own unilateral tariffs on polysilicon exports from U.S. producers such as REC Silicon. No one benefits in a global solar trade war.