Island stays cool on winter power usage
April 29, 2011 · 12:12 PM
Even with La Nina, the island made it through the winter without exceeding Puget Sound Energy’s usage threshold during the first of a three-year challenge.
“While the community did well this year, there are clear opportunities for reducing the energy problem next year,” said Linda Streissguth, PSE spokesperson. “Hopefully people are going to be getting their homes weatherized, reducing their energy usage and following up on what we are suggesting through RePower Bainbridge. Then we will be poised to have a successful winter next year,too.”
In October, PSE announced that it would give islanders three winters to reduce their energy usage through the RePower challenge before it pursues building a new substation and transmission line. This winter the island stayed below the 58-megawatt (MW) threshold that PSE warned would trigger the new infrastructure needs.
The many older homes on the island and outdated infrastructure have been a problem for years. The average Bainbridge home uses 19,000 kWh per year as compared with 11,797 kWh, the average usage for the other PSE-supplied cities. PSE approached the city last year after the island peaked over the 58 MW three times in the 2009-2010 winter; a dangerously high peak load for the system.
Streissguth said this year was a positive step in the right direction, but La Nina did leave its mark. Power was wiped out for the entire island twice during the coldest days of the winter in the four-day Thanksgiving week storm.
“I don’t think anyone knows what the peak loads would have looked like had there not been a major service interruption during that week,” said Streissguth. “It was a difficult winter not just on the island, but across the county.”
The goal is to drop general island usage by two MW every year for the next two years. Reducing two MW would mean every residence reduces consumption by 832 kWh, which is roughly the energy it takes to power a refrigerator or to charge 606 electric vehicles all plugged in at once.
In order to reach that goal, one program piloted by PSE this winter was a demand response program. PSE had 700 slots for homeowners to sign up to have their heat cycled on and off for brief intervals during peak energy periods to reduce the load. Only 500 customers signed up for the program and feedback was both positive and negative, said Gretchen Aliabadi of PSE.
The devices were able to shave off nearly 0.5 MW off the peak load, but problems were encountered with the thermostat and the need for a battery back-up. If all islanders used the device there is potential to reduce the peak load by 10.7 MW, but more analysis is needed.
Aliabadi said PSE will do a full review of the program in September.