NREL-led workshop points to path for clean energy future

(Press-News.org) Participants in a workshop organized by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) agree on the importance of mitigating degradation rates for the continuing rollout of clean technologies.

Renewable energy is forecast to play an expanded role in meeting future needs, with terawatts of electricity expected to be generated from wind and solar, so the performance of the technologies involved is becoming increasingly important. Any technology degrades over time, so researchers are looking at ways to curb this issue. Mitigating degradation will become a factor for both national energy security and economic health. At such large scales, clean technologies working as long as possible hold the potential for billions of dollars in savings through improved system performance and longevity.

The recommendations derived from the cross-cutting gathering of scientific minds from industry, universities, and national laboratories come amid an increasing reliance on electricity generation from renewable sources and the White House’s goal of a net-zero carbon emission economy by 2050. More than 50 experts outlined an ambitious pathway that could ultimately become part of industry standards.

The workshop followed a year of regular meetings among NREL researchers.

“We hope to inspire other people and more effort on this,” said Dirk Jordan, a distinguished member of research staff at NREL and lead author of a newly published paper outlining the recommendations. “In the paper, we're making the argument we're at a decent scale in terms of renewable energy. But as we hopefully grow that more and more and there's more emphasis on degradation science and understanding the science behind it, it will really pay off in 10 years. But we have to lay the foundations now and invest more in that.”

The paper, “Nanoscale Science for Terawatt/Gigaton Scale Performance of Clean Energy Technologies,” appears in the journal Joule. The other co-authors, all from NREL, are Steven Hayden, Nancy Haegel, Paul Veers, Shaun Alia, Teresa Barnes, Ashley Gaulding, and Katherine Jungjohann.

The cross-disciplinary, two-day workshop examined the commonalities across various technologies, identified areas for synergistic work, and outlined a path forward. Solar, wind, batteries, and electrolyzers are at various stages of technology readiness and deployment, but all share the same challenge. The participants noted the lack of sufficient, accessible reliability data and urged the strengthening of the feedback loop between manufacturers, research and evaluation laboratories, and field tests.

“Several high-level issues were identified,” Jordan said. “Obviously, there's differences between all those technologies, but there are also commonalities.”

The starting point, the participants pointed out, is the need for reliability data. For various reasons, including proprietary concerns, manufacturers have little incentive to publicize this information, and earlier-stage research often does not reach the step where reliability is tested. National laboratories and international research institutions can play a role here, the paper pointed out, by distilling and de-risking proprietary data for public knowledge. They also emphasized the need for “robust and shared collections of actual degradation and failure data.”

Also considered important is an atomistic examination of a technology, which can reveal stressors and allow for the identification of weak points in the material or structure. The researchers pointed to how microscopic examinations of bearings in the failing drivetrains of wind turbines discovered cracks. Manufacturers were able to use this information to solve the problem of unexpected failures caused by the bearings. This understanding allows for design changes to be made that can mitigate degradation.

The various technologies share “a need for ongoing and expanded attention to degradation mechanisms and mitigation across size scales,” the researchers noted. That includes accelerated tests that take different stressors into account, with that information then used to develop standards.

The researchers said identifying the causes of degradation continues to be a challenge for energy storage and electrolysis. Decades-long work into solar and wind has enabled manufacturers to mitigate the degradation rate for those technologies because equipment failures and performance loss in the field generated new ideas to cure the problems. That research contributed to the development of international standards, which in turn has improved the durability of wind turbines and solar modules. Standards development is needed for the other renewable energy technologies as well, according to the journal article.

“Standards typically lag behind cutting-edge technology,” Jordan said. “It takes time to develop standards. Typically, it's done by a committee and based on volunteers. That’s usually a few years. That's a challenge. But they are necessary to ensure reliability in the future. There's no question about that.”

The publication of this report was funded by the Laboratory Directed Research and Development program at NREL.

NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for DOE by the Alliance for Sustainable Energy LLC.

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