A report on Minnesota’s renewable energy potential challenges what has become a common assumption about energy storage and the curtailment of solar power generation.
The Solar Potential Analysis (SPA) report found that wind and solar power could serve 70% of Minnesota’s electrical load in 2050, but “additional capacity coupled with energy curtailment is considerably less expensive than, and a viable alternative to, long-term or seasonal storage in a high renewables future.”
Essentially, “it is cheaper to overbuild solar than it is to add enough storage to avoid curtailment,” Josh Quinnell, senior research engineer at the Center for Energy and Environment and a contributor to the report, told Utility Dive. “That is not to discount storage. Storage is still important,” he added.
The report, in fact, found that storage is a significant part of a high renewables future because it expands the dispatch capabilities of wind and solar assets and can smooth out the intra-hour variability of solar and wind generation. But, especially at higher levels of renewable penetration, it is more cost effective to overbuild a solar power facility than it is to add enough storage to offset the risk of solar power being curtailed during periods of peak output, Quinnell said.
“We don’t have all the answers, but certainly the results challenge traditional thinking,” Quinnell said. In most current conversations, “curtailment is to be avoided at all costs,” but the report found that “curtailment is a viable strategy.”