How will the technology and policy changes now sweeping through the industry affect the architecture of the utility grid? Will America build an increasingly robust transmission infrastructure, or...
Utility projects advance the state of the art.
grid more stable and reconfigurable.
The test will be carried out over the next three years on a portion of SDG&E’s existing distribution network in Borrego Springs, a rural community of about 3,000 mainly residential customers at the eastern edge of the utility’s service territory.
The area is served by a single substation and historically has had reliability problems, making it a good candidate for the pilot. The project will consist of three circuits and include existing or planned distributed generation assets operated by the utility, as well as businesses and residential customers. SDG&E’s AMI program, which will install 200,000 smart meters by the end of the year and a total of 1.4 million by the end of 2011, also will play a key role.
“We tell regulators that the smart grid is not a revolution, it’s an evolution,” says Tom Bialek, chief engineer on the project. “We need R&D funding to explore and demonstrate the benefits of technology now so we can come back to them with a larger-scale application later on. It was received favorably by the California Public Utilities Commission and the California Energy Commission. They view this as a step towards meeting the state’s energy goals of incorporating more renewable energy, providing energy choice and lowering electricity bills.”
SDG&E will install sensors and controls to continuously monitor and control the microgrid’s operating conditions. It will monitor, for example, power produced (or capable of being produced) by utility- and customer-owned generation inside the microgrid zone, including solar generators, storage capacity and commercial and industrial on-site generation. It also will be able to monitor the impact of demand-response measures, if and when they’re activated. All of this will allow SDG&E to manage the amount of electricity used by customers on the three circuits.
“We’ll know real-time electrical demand and the distributed energy resources that are available,” explains Lee Krevat, director of SDG&E’s Smart Green Grid initiative. “If a customer is generating power with solar panels, for example, we need to know that because of the intermittent nature of renewable resources. Right now we have an optional demand-response program for central air conditioning, but we don’t know whether a unit is actually running when we call the event. With sensors and AMI, we’ll know the exact impact of the demand-response program and whether we need to leverage other assets, such as energy storage. If necessary, we’ll be able to isolate that area from the rest of the grid without an outage to customers.”
The overall goal is to achieve greater than 15-percent reduction in feeder peak load, integrate its AMI smart meters with microgrid operations, demonstrate VAR management and integrate feeder automation technologies. That, in turn, will let SDG&E better integrate an outage management and distribution management system into the microgrid operations.
“This is an alternative service delivery model where customers are viewed as potential energy resources rather than simply consumers,” Bialek says. “We’ll be able to access distributed generation, renewables on both the customer and utility side, energy storage, reciprocating engines, and demand response. All this will be available to