Grid grief: Facing ‘voltage collapse conditions,’ PSE plans millions in investments on peninsula
Powering the Peninsula, Part 1: Kitsap County’s power grid is becoming more unreliable and stressed. How does it work, and how will PSE fix it?
Kitsap Sun
GORST — Kitsap Peninsula's electrical grid is growing more unreliable and antiquated and will require tens of millions of dollars in upgrades in the next decade. That includes proposals to construct power stations west of Bremerton and add a battery-fed power storage system on Bainbridge Island.
Research by Puget Sound Energy, Kitsap County's power provider and the largest utility in the state, shows it faces a host of challenges in response to climate change to keep electricity flowing for its one million customers.
The peninsula's power grid either needs more electricity sources or conservation from its customers if it is to avoid the risks of blackouts, PSE found in one study, performed in 2018. The study also found that eight of the company's Kitsap transmission lines "exceeded their emergency limits" for reliability.
Further, PSE also found local power generation will be necessary to keep the grid operating in the future at peak times. Failure to act could cause lines to carry too much load and cause power to go out.
"The Kitsap Peninsula needs are so great the peninsula load would need to be reduced by more than 30 percent in the near term to reduce all ... thermal overload and voltage collapse conditions," the study states.
Thermal overload is an overheating of power lines that, on a larger scale, is akin to plugging too many electrical devices into a circuit at home. The effect can damage the lines and cause low voltage, power outages, and even the risk of fires, according to Dave Townsend, an electrical engineer who worked as a transmission system planner for Puget Sound Energy for three decades.
"Conservation will still be a big part of PSE’s energy strategy in Kitsap County, but it will not be enough to accommodate the increasing electrical loads of the projected population growth and the increasing electrification of a greener society over the next decade," Townsend said.
Townsend is a consultant on a project to construct a biodiesel power plant, at Ueland Tree Farm near Kitsap Lake, which could help take on some of the power load. (While PSE has invited proposals to help generate power for its grid, it is not involved in the project, and has not yet commented publicly about it.)
Yet another project, this one proposed by New York-based Novis Renewables, would build a bank of batteries off Bremerton's Sand Dollar Road, totaling 125 megawatts. The energy storage facility, just north of Gorst, could feed the electricity grid at peak use times, according to documents filed with the Kitsap County Department of Community Development.
Aging electrical grids are not unique to Kitsap and Washington. Some, like the century-plus high transmission lines, have led to devastating wildfires like those in California in 2018. But Kitsap County, being surrounded on nearly all sides by water, has a challenge most areas in the United States do not.
"The geography doesn't help because it limits the options for bringing in new transmission lines," said Daniel Kirschen, professor of electrical and computer engineering at the University of Washington.
How Kitsap's power grid works
Kitsap residents from Olalla to Bainbridge Island rely on a network that begins in Gorst. High transmission lines owned by the Bonneville Power Administration bring electricity there, where it is dispersed throughout the peninsula on lines owned by Puget Sound Energy.
Bonneville also has two massive bulk transformers in Gorst, each capable of handling 230 kilovolts of power. They're aging: 46 and 57 years old, respectively. The loss of either would result in widespread outages. During that time it would "put PSE’s Kitsap load at risk of a large outage or voltage collapse for the next major contingency during peak winter conditions," PSE said in its study.
Other than through the south end of Kitsap, the only other way to bring bulk power here is via undersea cables near Vashon Island and the Edmonds-Kingston ferry route. But those routes are old, undersized and would be cost prohibitive to route power through, Townsend said.
Census records show close to 50,000 more people live in Kitsap since 2000, placing increasing demands on an electricity grid of 28 substations and 18 transmission lines. More Kitsap residents are also installing air-conditioning and, thanks the COVID-19 pandemic, working from home and using more power throughout the day. To top it off, a small but increasing number of drivers are purchasing all-electric vehicles, placing further strain on Kitsap's power.
During harsh winter months, Kitsap County relies on its electrical grid more than other counties in Puget Sound because natural gas is less available as a heating source here, Townsend pointed out.
So Kitsap's electrical grid needs one of two things: a costly new set of transmission lines into Kitsap, requiring construction and property purchases, or the construction of a power plant on the peninsula to generate its own power.
"There are only two alternatives to supplying Kitsap County with this energy — another bulk transmission line and generation from another county or locally owned and controlled generation," he said.
Meanwhile, PSE has another problem: the growth of renewable sources like wind and solar power have nowhere near compensated for the closures of heavy carbon emitters such as the Centralia Power Plant, where the last coal-fired burner will power down in 2025. Puget Sound Energy still gets almost 50% of its power from coal and natural gas.
“We are adding more to the grid in an effort to be more green, but we're also mandating the closure of some sources of power,” said Lynn Eaton, spokeswoman for Mason County Public Utilities District 3. “At the same time we’re adding load, we’re reducing our ability to carry that load.”
Renewable sources like wind and solar tend to be generated on the eastern side of the state – there’s more sun, and fewer complaints about wind farms – so costly transmission lines must be built to transport that power west, which takes time.
And renewable sources aren't always generating power.
"But the sun doesn't always shine and the wind doesn't always blow," Kirschen said.
What is certain is Puget Sound Energy will have to make investments to divest its power sources, and that's going to come at a cost to ratepayers. Earlier this year, the utility proposed to the Washington Utilities and Transportation Commission a nearly 13% increase in electric bills, starting in 2023, which would result in an average increase of $12 per month for customers.
'Resiliency' projects for Bainbridge, Seabeck coming
Kitsap's needs go beyond its growth, however. The grid needs greater resiliency in the face of storms and other possible outages. In the electricity business, engineers measure a grid's reliability by what happens if one of its main sources of power goes down. In Kitsap, there are three main transmission lines that arrive at Gorst. If one goes down in the future, there is concern over whether the other two could handle the load.
So reliability has become Puget Sound Energy's focus around Kitsap. The utility plans to make substantial upgrades in Seabeck and also install the biggest bank of battery power in the history of the utility at the Murden Cove substation on Bainbridge Island.
"For both Seabeck and Kitsap County, needs have been identified and PSE is comparing solution alternatives," PSE said in a statement to the Kitsap Sun. "In Seabeck, a smaller circuit capacity and reliability need was identified and in Kitsap County PSE has identified capacity, aging infrastructure and operational flexibility need."
Puget Sound Energy did not confirm the power plant project at Ueland, saying it is still "in the process of studying the solutions."
"Once that is complete we will be working towards the appropriate solution and it may or may not include proposals necessary to reinforce the grid," PSE said in a statement.
On Bainbridge, Puget Sound Energy plans to build a battery facility at its Murden Cove substation that will provide 3.3 megawatts of power, charging those batteries during low demand and using them during peak times. The utility is also installing new lines and replacing old equipment in the island's south end to increase reliability to go with a previously announced project to connect transmission lines between two substations that will create a loop.
Meanwhile, PSE said in a statement to the Kitsap Sun it is still working to identify which solutions fit best for the peninsula.
"No specific project has been launched because we are in the process of studying the solutions," PSE spokesman Andrew Padula said. "Once that is complete we will be working towards the appropriate solution and it may or may not include proposals necessary to reinforce the grid."
Coming Monday: Ueland Tree Farm plans to build a biodiesel power plant just west of Bremerton.
