Testing technologies off-the-grid proves valuable
Published In: Intelligent Utility Magazine January/February 2011
WHILE CLIMBING FROM UTILIQ'S FOURTH spot in 2009 to third place in 2010, PG&E Corp. also weathered a tempestuous media storm in the past year, and earned every point of its third-place finish.
The utility first installed what we now describe as traditional meters to measure electricity used by customers in 1912. In the 1970s, PG&E began its first energy conservation programs, actively working to help its customers reduce the use of the company's product. PG&E soon became one of the leading utilities in the nation in energy conservation, and remains so 40 years later.
Distribution automation driving improved reliability
Today, the company has moved quickly ahead in its efforts to lay the foundation for the smart grid with its transition to SmartMeterT technology. PG&E's goal is to have in place 10 million new electric and gas meters by mid-2012, along with new energy management tools and capabilities, with the objective of improving customer service, increasing reliability, expanding energy efficiency and demand response, and optimizing the use of renewable energy sources and electric vehicles.
As so much of the public and media focus in the past year has been on the utility's smart meter deployment, I spoke with Kevin Dasso, PG&E's senior director of smart grid and technology integration, about the other intelligent utility efforts PG&E is also working to implement.
One of the biggest is its Cornerstone Improvement Program, a $366-million, three-year program recently approved by the California Public Utilities Commission to improve electric distribution system reliability for a number of the utility's more than 5 million customers.
The program will use the latest generation of distribution automation technology to isolate outages and redirect power flows onto neighboring circuits. Such a strategy would restore service to as many customers as possible in the shortest period of time, using sensors and automated switches out on the circuits. "Our target is to do that in less than five minutes," Dasso told me. "The reality is that it usually only takes about a minute."
PG&E is looking beyond its distribution lines to transmission issues, too. In September 2010, it inked a deal with the Western Electricity Coordinating Council (WECC) and part of the Western Interconnection Synchrophasor stimulus grant project, and the utility is well into detailed design and prototyping at its test facility, and should have a prototype facility completed in the first quarter.
Synchrophasors and phasor measurement units (PMUs) are a new evolving area, with the devices taking in data measurements 20 to 40 times per second. "First is getting the data, and that's not a trivial matter," Dasso said. "Then there is a different telecommunications system design; the ability to store the data, and to display it to operators in a way that is useful."
The monitoring system project PG&E is working on with the WECC will be implemented by early 2013. "Once it's in place," Dasso said, "it will continue to evolve for many years to come."
Demand response and energy storage
PG&E is also working with the California Independent System Operator (ISO) on an expanded demand response program. "We are testing the ability of our demand response programs with specific customers, to see how quickly they can respond to signals sent to us by the California ISO from a renewable energy resource area," Dasso explained. "We want to see if demand can firm the intermittency of renewables." PG&E is also testing whether the best response is automatic or manual in nature.
"The reality is, it will need to be done in an automated way, built into building management systems," he said.
The utility has also launched a number of different energy storage projects to better balance the intermittency of distributed renewable generation. According to Dasso, there are four different types of energy storage projects under way.
"A basic challenge with electricity is that it can't easily be stored; it has to be used almost immediately," he said. "So we are constantly balancing generation output with customer demand."
One project planned includes compressed air energy storage (PG&E was awarded a stimulus grant for this project, and is still finalizing its contract with the DOE), in which it would like to use an area with unique geological formations to pump air in the ground and store it until needed to power a turbine generator. PG&E's project is focused on providing 300 MW for up to 10 hours by using this compressed air storage. The first steps will be to do environmental studies, preliminary permitting and initial design work.
The utility has also recently requested approval from the California Public Utilities Commission to develop a large pumped hydro storage project in the Sierras using next-generation technology that will provide the utility with a much shorter response time than traditional or existing pumped storage technology.
On a more local level, PG&E is exploring battery storage on its distribution system, including a 2-MW battery at one of its substations to firm solar energy being supplied, and a 4-MW battery sitting on the distribution system away from the utility's substations to provide ancillary services such as frequency response, load following and avoidance of sustained outages. Finally, it is has lined up almost 700 MW of demand response at customers' sites including the use of thermal energy storage.
Engagement: interesting, immediate, important
There are really two different kinds of smart grid projects, Dasso told me. First are the projects that a utility can do on its own, that don't require customer involvement. "These are more around technologies on the grid and how it works to deliver energy, and the processes are in place for them," he said. And then there are the projects that directly involve customers. "The key here is engaging customers early," Dasso said. "We're focusing on doing that as we continue to deploy smart meters."
One way PG&E is engaging customers is via its Web site, where smart metered customers can access their hourly data the very next day, and clearly view how much electricity they used, and how much they paid for it. Currently, more than 250,000 PG&E customers access that personal data.
"Customer engagement is really key. You have to find ways of making it interesting, immediate and important," Dasso said.