By Connie Lewis
According to Shining Cities 2017, a recent report by Environment California Research and Policy Center, San Diego topped a ranking of 66 U.S. cities with 303 megawatts of solar PV installed in 2016. Los Angeles came in second with 267 megawatts.
Solar installers enjoyed booming sales of rooftop solar during a decade of steadily declining prices and the first iteration of net energy metering (NEM 1.0), which allowed customers to sell their excess green power back to the grid at a retail rate. Following a buy-back cap that allowed the state’s investor owned utilities (IOUs) to essentially dilute their returns to green energy producers NEM 2.0 went into effect at the beginning of this year. And while NEM 2.0 kept the attractive retail rate in place, it created a fee structure for signups and introduced different time of use rates that put more money in the IOUs pockets. A harder sell.
Yet San Diego’s rooftop solar PV potential for small buildings is 2,219 MW, while the potential for LA is 5,444 MW, the Shining Cities report stated. The most recent estimate by the U.S. Census Bureau pegged San Diego’s population to be 1.4 million in 2015. By contrast, LA’s population stood at 4 million.
“Even cities that have seen the greatest solar success still have vast amounts of untapped solar energy potential,” the report said. “For instance, San Diego has developed less than 14 percent of its technical potential for solar energy on small buildings.”
But as the San Diego-based Center for Sustainable Energy (CSE) pointed out, realizing that full potential calls for renewable energy storage batteries.
The way things stand now, an overabundance of green power coming from utility-scale facilities and rooftop solar installations occurs during daytime hours when electricity demand is lower than during the evening hours. This results in curtailment of generation sources, including wind and solar.
“The challenge is to match our daytime supply of clean renewable power with the actual demand for electricity, which now peaks in the evening. Fortunately, California is poised to turn this challenge into opportunity by putting power into battery storage for use when it’s needed,” CSE said.
Yet an immediate response to this challenge has IOUs and the state Public Utilities Commission designing TOU rate periods that graduate in price later in the day. They theorize that if homeowners know they’re going to have pay more money to turn on their lights and use appliances, such as dishwashers, washing machines and dryers in the evening hours after they come home from work, they’ll adapt by shifting the use of such appliances to times when rates are lower. Maybe.
Another, more viable solution to the problem is energy storage. To help meet its state-mandated quota of 165 MW of battery storage by 2020 - part of an overall 1,325 MW for utilities statewide - San Diego Gas & Electric unveiled a 30 MW facility in Escondido in late February, which can store up to 120 megawatt hours of energy, the energy equivalent of serving 20,000 customers for four hours.
California's Renewables Portfolio Standard requires all utilities in the state to source half of their electricity sales from clean, renewable sources such as wind, solar, geothermal, and biopower by 2030.
When SDG&E had reached its 5 percent NEM 1.0 cap in late June 2016, independent sustainable energy interconnections stood at 93,569 for a total of 96.3 MW. As of late February, under NEM 2.0, the utility had connected another 13,388 for a total of 96.3 MW.
Analysts insist that if California and other states that have adopted sustainable energy standards in the aim of reducing their carbon footprint, battery storage is the only way it’s going to happen.
Hear, hear! iDemand Energy Storage, a San Diego-based manufacturer of revolutionary sustainable energy storage batteries, co-founded by Walter Ellard and Ray Trejo, opened its doors in late August, and already has a list of clients, including homeowners and business owners, whose projects are valued at more than $10 million. To meet growing demand the company has added 20 employees to its original staff of four and moved its headquarters from a 5,000-square-foot office in Miramar to nearby offices with three times as much space.