The California Public Utilities Commission (CPUC) in December proposed big changes to the state’s distributed solar net energy metering incentives as the state grapples with a growing pain point for electric grids everywhere: How can utilities maintain an affordable, reliable grid for all customers with increasing amounts of intermittent and distributed energy sources that stress the technical limits of grid infrastructure?
This is new territory and, understandably, confusion exists about how to transition the grid to successfully manage today’s changing demands. Fortunately, there is an easier, less costly and more certain alternative for utilities to solve many of their most pressing grid challenges.
Microgrid controllers placed at strategic points on the grid can effectively manage distributed energy resources (DERs). They can be implemented today to address common grid challenges at lower cost and with less disruption to operations than many realize.
Layer of microgrid controllers
A layer of microgrid controllers at grid-edge locations offers instantaneous, automatic control of assets. The automated controls can be applied at substations, front-of-the-meter and behind-the-meter microgrids, utility-owned renewable energy resources like solar farms, behind-the-meter battery energy storage systems and campuses.
For example, when customer-owned solar systems cause voltage fluctuations at a substation, a microgrid controller offering real-time control keeps the grid reliable with sub-second decision making.
While the CPUC has proposed an $8 per kilowatt per month grid participation charge for residential solar owners to help pay for the electric grid upgrades needed to accommodate these distributed resources, microgrid controllers could provide the necessary initial grid improvements in many areas at a much cheaper rate per customer.
In PXiSE’s recent white paper, Microgrid Controllers: Rapid Relief for Today’s Dynamic Grid, we detail six primary ways in which microgrid controllers solve common modern grid challenges all at once.
Controllers in action
On the Pacific island of Guam, PXiSE has already partnered with the Guam Power Authority to demonstrate the benefits these controls provide to address today’s grid challenges and advance toward a resilient, renewable grid.
Guam struggles with many of the same challenges seen in California and around the US. There is severe weather in the form of typhoons, a growing number of customer-owned distributed energy resources like rooftop solar, growing demand for electricity (in Guam’s case, from US military operations), and a large-scale solar farm plus legacy petroleum-based generation serving as the main sources of power supply.
The Guam Power Authority’s grid upgrade turned out to be less costly and time-intensive than first imagined because it was largely accomplished through software. PXiSE deployed two Microgrid Controllers: one at Agana for frequency control and one at the 25-MW solar farm in Talofofo. These two controllers provide real-time asset control and tight ramp-rate control, ensure connectivity to virtually any device on the grid, aggregate power from the solar farm and battery systems to create a single virtual power plant, and establish a system foundation that is scalable, reliable and safe.
The controls used in Guam solve the intermittency issues caused by weather, effectively manage the existing renewable and legacy DERs and create capacity for future DER additions. Equally as important, this kind of infrastructure upgrade can be deployed in four months or less, and local staff needed just a brief four-hour training session to use the system.
Regulators and utilities keen to find the simplest, most affordable solutions to preserve grid reliability while encouraging the zero-carbon benefits of distributed solar energy should take note.
Becky Wheeler is head of marketing at PXiSE.
