NGRID Seeks to Stay “Ahead of the Game” with Solar Grid Penetration
On May 9, Trimark Associates announced that it would be implementing its supervisory control and data acquisition (SCADA) technology at two 1-MW solar PV sites in Fall River, Massachusetts. Borrego Solar is building the projects, which are part of a test bed of 14 PV generation sites owned by National Grid.
Stephen Yee, the Director of SCADA Engineering at Trimark, said that National Grid is concerned that with increased penetration of PV on circuits, voltage problems may arise. According to Yee, the utility is being tasked with “looking at not your traditional ways of handling voltage through your voltage regulators but taking advantage of some of the advanced inverter controls that are available at these particular sites.”
He added, “So we have been contracted through Borrego Solar to help them develop these advanced inverter controls.”
According to Yee, Trimark’s system mitigates grid issues related to distributed energy resources by providing grid stability support. It enables grid operators to manage point-of-interconnection (POI) power characteristics in real time by taking advantage of and integrating many of the advanced controls that inverters already possess. “Our core competency is having the ability to integrate all of the devices,” he said.
Providing stable, reliable power to the grid from a PV system is becoming increasingly important, especially in places like California and Hawaii where PV penetration is large. “What we are seeing right now out there on the grid, there are a lot of different variations, you hear a lot about voltage regulation and a lot about power factor control,” said Yee. He said that Trimark has worked on solving some of the “more complex” algorithms such as when a utility might want a PV system to operate at a fixed power factor within a particular voltage range and then “outside of that range, they want you to provide frequency regulation.”
As utilities make greater demands on the power quality that PV systems supply, having greater control at the POI could be increasingly important.
While the site owner purchases a system like Trimark’s, the host utility would also have control of it. This is something that Yee is seeing more and more of particularly in California. He explained that sometimes a new developer that is working in SCE territory will be unfamiliar with utility requirements and SCE will refer them to Trimark.
While PV penetration is not as large in Massachusetts as it is in California, utilities are already “seeing the effects [of PV on the grid],” said Yee.
“Lessons learned, right? You don’t want to repeat what happened in Germany where the utility is going to go out and have to retrofit every single inverter out there,” he said.
“I think the simple way to put that is they are trying to get ahead of the game before there is a problem,” said Yee.