Make way for more microgrids: SDG&E adds 4 in these neighborhoods (msn.com)
Story by Rob Nikolewski, The San Diego Union-Tribune • 3d
San Diego Gas & Electric's 10-megawatt Paradise Microgrid project is one of a growing number of facilities that can operate independently or in tandem with the regional electric grid.© Rob Nikolewski/The San Diego Union-Tribune/TNS
Micro is quickly becoming macro.
San Diego Gas & Electric has unveiled four new microgrids that will go online within the next 90 days, boosting the number in its service territory to eight — and the utility has plans to build at least three more in the next two years.
Growing in popularity in California, microgrids essentially act as mini-electric grids that can supply power to a defined area while operating independently of the conventional electric power system for hours at a time during emergencies, such as power outages or when the state's electric grid is under stress.
The new microgrids are in Clairemont, Tierrasanta, Paradise Hills and the East County town of Boulevard.
The facilities are connected by circuit to substations in their respective sites, and can operate remotely or in tandem with the larger regional grid.
The systems are powered by energy storage batteries. There have been instances of batteries catching fire, but the four SDG&E sites are powered by lithium iron phosphate battery cells that are considered safer, with less risk of fire.
"Safety-wise, this is probably the most-state-of-the-art as it comes right now," said Don Balfour, SDG&E's project manager for clean technology. "You have gas detection, fire detection, smoke detection. All of that's embedded inside now."
The four microgrids offer combined storage capacity of 39 megawatts and 180 megawatt-hours. SDG&E officials say that's enough to supply power to about 26,000 homes for four or more hours when needed.
The 10-megawatt Paradise Microgrid has the ability to power the Southeast Division Police Department, Fire Stations 51 and 32, one middle school and three elementary schools in the area. The energy storage system is connected to SDG&E's Paradise Substation next door.
Adjacent to SDG&E's Elliott Substation, the 10-megawatt microgrid in Tierrasanta has capacity to power Fire Station 39, the area's medical center, the Tierrasanta Public Library and Cool Zone during heat waves, one middle school, two elementary schools and Canyon Hills High School.
The Clairemont microgrid can serve Fire Station 36, the Balboa Branch Library and Cool Zone. two elementary schools, a middle school and Madison High School with 9 megawatts of capacity. The microgrid is connected to SDG&E's Clairemont Substation near Derrick Drive.
Linked to an SDG&E substation, the 10-megawatt microgrid in Boulevard serves as many as nine facilities that include three fire stations, three tribal offices and health care facilities, the Boulevard Border Patrol Station and the town's post office.
"These collaborations ensure that our communities have the necessary resources and infrastructure needed as we strive to meet our climate goals," said Miguel Romero, SDG&E vice president of energy innovation.
California policymakers intend to derive 60 percent of the state's electricity from renewable energy by 2030 and 100 percent from carbon-free sources by 2045.
With those renewable energy targets in mind, legislation out of Sacramento and mandates from the California Public Utilities Commission have ordered investor-owned utilities such as SDG&E to add microgrids and energy storage facilities to their power portfolios.
The projects can also help the California Independent System Operator maintain the state's electric grid.
Solar production during the day is abundant but virtually disappears after the sun sets, which drains the power system of valuable megawatts of clean energy — especially on hot days when consumers use their air conditioners into the early evening hours.
Batteries can help solve the problem by storing the excess during the day and then deploying those molecules at the same time solar production wanes each evening.
But the costs of storage and microgrid projects are folded into the rates utility customers pay in their ever-increasing monthly bills.
As per California Public Utilities Commission rules, the costs of the four new microgrid projects will be kept confidential for at least three years. But SDG&E officials say constructing the facilities next to existing substations helps defray costs that get passed onto ratepayers.
"We just came through very severe storms," Romero said of the recent dumping of rainfall that flooded some areas of San Diego, "and from an outage standpoint, this will be able to protect you from that. But ultimately, this asset is providing further benefits to the region and to the state of California in meeting its renewable supply needs."
SDG&E has four other microgrid projects that are already up and running — an 8-megawatt facility in Borrego Springs, 2 megawatts at the Miguel Substation in Bonita, 1 megawatt in Carmel Valley and a one-half megawatt facility in Ramona.
Besides utilities, community choice energy programs such as San Diego Community Power and the Clean Energy Alliance are looking into microgrid projects. Municipalities are getting into the act, too.
Last summer, the city of San Diego unveiled the first of at least eight microgrids that will be built at city facilities.
This story originally appeared in San Diego Union-Tribune. |
