DOE holds back ‘super-grid’ renewable study

Source: By Peter Behr, E&E News reporter • Posted: Sunday, October 27, 2019

A comprehensive laboratory study of how a new, continent-spanning transmission network could dramatically expand renewable energy resources to U.S. cities is being held back within the Department of Energy headquarters, speakers at a transmission conference said yesterday.

The analysis by DOE’s National Renewable Energy Laboratory, called the Interconnections Seam Study, “has been bottled up inside DOE,” said Charles Smith, executive director of the Energy Systems Integration Group, a Reston, Va., consulting group on power grid planning.

“The study has been finished for a while,” said Christopher Clack, chief executive of Vibrant Clean Energy LLC, a power grid modeling firm based in Boulder, Colo.

“I feel like it makes uncomfortable reading” for some at DOE, he added at the forum yesterday held by the WIRES advocacy group; the Embassy of Canada; and 16 energy, environment and labor organizations. “The analysis retires a lot of coal” by expanding delivery of wind and solar power, Clack said.

Some details of the NREL analysis were previewed at a July 2018 symposium in Ames, Iowa. The research makes the case that building a “super-grid” of long-distance high-voltage direct-current (HVDC) power lines could connect the best U.S. sources of wind and solar power with distant population centers (Energywire, July 27, 2018).

The report is titled the Interconnections Seam Study because of its strategy for linking the eastern and western U.S. grid networks, now separated by the Rocky Mountains, into a unified, country-spanning grid.

Such a connected network would allow power to be shipped across time zones, allowing surplus solar power in Arizona and California to be transported east to Chicago, for example, or for Great Plains wind power to be moved to the eastern U.S. early in the day.

NREL’s description of the research project states, “Through the Interconnections Seam Study, NREL joins national lab, university, and industry partners to identify cost-effective options for upgrading the U.S. electric grid to create a more integrated power system that can drive economic growth and increase efficient development and utilization of the nation’s abundant energy resources, including solar, wind, and natural gas.”

The value of HVDC lines was described at the Iowa conference last year by Aaron Bloom, an NREL research group manager. “We can do thousand-mile lines with a massive amount of controllability,” Bloom said of HVDC circuits. “The term I’m using for it is the idea of a transmission renaissance. What if we build transmission in the U.S. as China is doing now?” he added. Unlike high-voltage alternating current, DC power flows can be easily directed to targeted destinations to be fed into the existing transmission and distribution networks.

Perry promises

Speakers at yesterday’s conference cited the potential of HVDC systems to help the grid recover from catastrophic outages.

Clack noted that transmission technologies continue to evolve, offering solutions to grid stability and security issues as well as carbon emissions reduction. Modeling of new overlay transmission networks shows that their economic benefits in cheaper power supplies would be as much as triple the cost of building the systems, speakers said.

Outsiders asking about the NREL study are told it is “under review,” Clack said. The NREL website notes that the study has had input and review from more than 30 utilities, power system operators and industry organizations in the United States and Canada.

A request to DOE late yesterday afternoon on the status of the NREL report did not produce a response. NREL’s contact on the report did not reply to a call yesterday, as well.

The analysis came up last summer in an exchange between Energy Secretary Rick Perry and Rep. Jerry McNerney (D-Calif.) at DOE’s fiscal 2020 budget hearing.

“Secretary Perry, one way to make energy from renewable sources that are remote available to load centers across the country is to better connect them with what we call interconnection seams. The National Renewable Energy Laboratory has completed a study on this,” McNerney said.

“However, the committee staff has informed me that the release of the report that contains findings from this study has been delayed without explanation, and the authors have been told not to discuss it publicly. Are you aware that the limits have been placed on the authors in discussing results of this study publicly, and whether these limits remain in place today?” he asked.

“I’m not,” Perry said.

“OK. So, will you make a commitment to make this publicly — this report available?” McNerney continued.

“Yes, sir, we’ll circle back and find out where that originated from and make it right,” Perry said.

McNerney’s press secretary, Nikki Cannon, yesterday said she has not seen a response from Perry on the question.