Solar Builder

JUL-AUG 2018

Solar Builder focuses on the installation/construction of solar PV systems. We cover the latest PV technology (modules, mounting, inverters, storage, BOS) and equip installers/contractors with tips and tools to make informed purchasing decisions.

Issue link: http://digital.solarbuildermag.com/i/992843

Contents of this Issue

Navigation

Page 22 of 47

SOLARBUILDERMAG.COM | 23 How solar + storage solutions are shaving peaks in C&I, leading to huge savings By Charles W. Thurston S having the peaks off commercial and industrial (C&I) electric bills is the top revenue stream for energy storage systems, and given the trend in increasing utility charges for time-of-use con - sumption, peak shaving can pay for a system in as little as three years, system providers say. Just how high the peaks need to be in order to justify the investment in an energy storage system varies with geography and jurisdiction, but in general, demand charges of $15 to $20/ kW or more are clear candidates, says John Merritt, the director of applications engineering at Ideal Power. "The vast majority of converters we sold for storage systems in the past year went to California, with eight out of 10 used in applications for peak shaving," Merritt says. "With the California incentives and the federal tax break, C&I customers can get a payback in as little as three years and in other cases in four or five years." A $15/kW demand charge threshold for economic feasibility also necessitates a 50-kW monthly usage level within the peak charge range, suggests Ellen Howe, VP of marketing and cor - porate development at JLM Energy, based in Rocklin, Calif. Her colleague, Nate Newsom, VP of enterprise sales, says, "Commercial entities that spend 3 percent or more of their monthly budget on electricity and/or experience 40 percent to 50 percent [higher than normal] demand charges typically are a good fit for energy storage." The C&I market is virtually untapped Analyzing the C&I market for energy storage usefulness, the National Renewable Energy Laboratory in Golden, Colo., started with the assumption that demand charges of $15/kW or higher typically result in favorable economics for energy storage projects. Then, counting rooftops, NREL determined that "Of the nearly 18 million commercial utility customers in the United States, almost 5 million of them are exposed to, or could be exposed to demand charges of $15/kW or higher that would indicate cost-effective opportunities for energy storage." While not every potential C&I customer will bite the bullet for a stand-alone energy storage system, aggregation through community solar projects, or virtual power plants (VPP), is increasingly an opportunity. Tesla is among the storage providers that is now active in community solar, with a high-profile October rollout of its commercial-scale Powerpack system at Puerto Rico's Hospital del Niño, a children's hospital in San Juan. As of April, Tesla had provided commercial Powerpacks and residential-scale Powerwalls to over 600 locations, with the count rising daily. The company has been quoted stating a goal of providing up to 40 percent of the island's power storage needs via community solar system build-outs. One new provider of VPP services is solar converter maker SolarEdge Technologies, which in May announced a solution for grid services and virtual power plants, thanks to its recent acquisition of Gamatronic Electronic Industries. The solution includes grid services of aggregative control and data reporting that enable the pooling of PV and storage in the cloud for the creation of VPPs. Storage + trackers (plus pumps, plus…) A relatively new storage configuration for C&I customers is the use of storage with solar trackers, like the 1.1-MW project at the Maharishi University of Management in Fairfield, Iowa. This project will use the NEXTracker NX Flow integrated solar-plus-storage system, in combination with an Ideal Power SunDial Plus converter and a Vanadium f low battery. The project is NEXTracker's first large-scale installation of the NX Flow solution. Another budding C&I application for storage is with water authorities, which can typically generate energy from solar for less than it costs to pump water uphill for a discharge to a gen - erator turbine. The San Diego County Water Authority, for example, won $1 million from the California Public Utilities Commission to install intelligent energy storage that will tap the energy from solar panels already installed at the SDWA's Twin Oaks Valley Water Treatment Plant. The SDWA energy storage project, being operated by Santa Clara-based ENGIE, is expected to save an estimated $100,000 per year by storing low-cost power for later use during high- demand periods for peak shaving. The storage will help the plant cope with its highest energy use period, during peak afternoon hours. ENGIE acquired majority control of energy storage management software leader Green Charge in 2016. The backbone of storage: data crunching It is tricky enough to coordinate a community solar or VPP operation, providing power on demand to participants and storing the rest until the utility calls for help. But knowing precisely what times, and advising customers as to when it is most optimal to use grid energy, or substitute with storage, is another matter, thanks to U.S. utility rate mayhem.

Articles in this issue

Archives of this issue

view archives of Solar Builder - JUL-AUG 2018