Lithium-ion batteries may grab a lot of attention in the conversation about energy storage these days, but on Wednesday panelists at POWER-GEN International shared insights about the benefits to today’s markets for other energy storage technologies, such as pumped storage hydro, flow batteries and compressed air/liquid air.
Kevin Young, president of Young Energy Services, promoted a pumped storage hydro project that uses an abandoned limestone mine as the lower reservoir. The project, which is a completely closed system, has minimal engineering issues that need to be addressed, he said.
He added that the U.S. Department of Energy’s Oak Ridge National Laboratory recently looked at the ancillary benefits of pumped storage hydro, identifying a total of 24 overall benefits.
“They found the newest benefits, especially if you have variable speed, reversible turbine units, are with wind and solar; for example, you could reduce curtailment of wind by up to 90 percent,” he said.
One audience member said that he is working with a group that is performing due diligence for collocating some very large solar projects with pumped storage hydro, mainly in South America. While he was unable to disclose the participants of the group, he said that the projects under consideration would have a capacity of approximately 1,500 MW.
Looking at energy storage technologies that are at much smaller scale, Daniel Loero, midstream director, North America turbo machinery solutions for GE, discussed liquid air energy storage (LAES) – with a capacity range of between 5 MW and 150 MW, and compressed air energy storage (CAES) – with a capacity range of between 50 MW and 200 MW.
He said that these technologies cost in the range of $800 to $2,000 per kW installed.
CAES and LAES, he said, use a generator that can help modulate frequency in the grid and provide stability, if that is a need. He added that, when considering a CAES/LAES project, it’s important to look beyond CAPEX at the lifecycle of a project. He said that, for example, the maintenance is minimal.
Ron Van Dell, president and CEO of ViZn Energy Systems, noted during the panel discussion that, when it comes to energy storage today, “people don’t want a one-service battery anymore.”
ViZn offers containerized energy storage solutions based on zinc/iron flow battery technology for commercial and industrial behind-the-meter applications, microgrids, and full utility scale applications.
Van Dell said that lithium-ion solutions tend to be the incumbent technology in many markets, especially, for example, in PJM Interconnection’s territory in the U.S.
“We’re focused on a battery that can cover the full range of power and energy service from one platform,” he said. “You can try to do that with certain flow battery technologies, but they won’t push power very well. You also can try to do that with variants of lithium technology…but you can be stuck with a ‘pick power vs. energy conundrum.’”
The problem, he noted is that in the “real world,” it’s not practical to map a singular storage technology to a singular application or service that you’re trying to support.
“The real world wants a mix of services and to address multiple revenue streams often on both sides of the meter and that are very different from each other,” he said.