Solar Storage Demo Kicks Into Gear

Nobody said cleantech would be shovel-ready, right? Two years ago, the U.S. Department of Energy announced 16 Recovery Act grants [PDF] totaling $185 million for utility-scale energy storage projects intended to enhance the reliability and efficiency of the grid. Now the first of those projects is up and running, with two made-in-America advanced batteries working to smooth, shift and store energy produced from a 500-kilowatt solar power plant in New Mexico.

The project, unfolding near Albuquerque, is headed up by the utility Public Service of New Mexico (PNM), which is actually picking up the lion’s share of the costs (around $6 million, with the 2009 stimulus kicking in $2.3 million). There, East Penn Manufacturing and its subsidiary Ecoult have integrated an advanced valve-regulated lead-acid battery (VRLA) and a hybrid battery dubbed the UltraBattery with the photovoltaic solar farm. The hope is that with better storage and integration systems, renewable power sources won’t have to be as reliant on fossil fuels as backup.

New Mexico solar-energy storage demo

image via Ecoult

According to Ecoult and East Penn, the advanced VRLA battery has design enhancements that protect it from accelerated deterioration while performing multiple cycles in applications in which the battery isn’t fully charged. These “partial state of charge”(PSOC) applications are often ruinous for batteries.

The companies said the UltraBattery has these same features, but also comes with an asymmetric super-capacitor in the same cell, without extra electronic control. “This enables the optimal balance of an energy storing lead-acid battery with a quick charge acceptance, power discharge, and longevity of a capacitor, which is critical for high-rate PSOC applications,” the companies say.

The companies noted that East Penn is commissioning a second site, at its manufacturing plant in Lyon Station, Penn., partially supported with Recovery Act funding. “This will be a 3-megawatt site and will provide continuous voltage smoothing using the UltraBattery,” the company said, and will “serve a secondary application of 1 megawatt-hour for demand management for one to four hours.”

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.