Historically, thermal concentrating solar plants were the only type of solar power equipped with storage. But as cheaper PV systems became dominant, thermal solar plants fell into disfavor. Now solar PV systems are beginning to integrate storage based on lithium-ion batteries, and this storage isn't just used to supply power when the sun is down; it is providing grid stabilization services too, which only adds complexity to an already-complicated picture for the future of storage - confounding attempts to model how much storage we’ll need, and of what kind, and when will we need it. Is a large amount of seasonal storage required on a high-RE grid, as some analysts have suggested? Or will other technologies reduce the amount of storage we’ll need? And can we even forecast that need, years or decades in advance? We’ll delve into all those questions and more in this deep dive into combined solar and storage systems.
Paul Denholm is a senior research fellow—the highest technical position at the National Laboratory of the Rockies (NLR), formerly the National Renewable Energy Laboratory (NREL)—leading research in grid applications for energy storage and solar energy.
When he first appeared on Episode #58 – Solar with Storage in December 2017, Paul was a principal analyst at NREL. Part of that conversation also features in Episode #286 – A Moving Target (2026). He returned for Episode #188 – Getting to a 100% Clean Grid in December 2022, as a senior researcher at NREL.
He pioneered a variety of research methods for understanding the technical, economic, and environmental benefits and impacts of the large scale deployment of renewable electricity generation. He has delivered over 100 invited presentations to agencies including the National Science Foundation, the World Bank, and the International Energy Agency. He has co-authored over 100 articles related to renewable energy integration. While his official title at the time of his first appearance was principal analyst, he is still an engineer at heart and in his free time he likes to build contraptions of dubious functionality, like a concentrating solar marshmallow cooker.
On the Web: Paul Denholm’s page at NLR
Recording date: December 1, 2017
Air date: December 13, 2017
Geek rating: 7