Clean energy projects bring $5.2 million in savings for WTD

If you hike to the top of the Power Quality Facility at West Point Treatment Plant on a clear, sunny day, you’re rewarded with a panoramic view of shimmery Puget Sound.

Turn around, and you’ll see something just as striking: a sea of 140 solar panels. This 80-kilowatt AC solar array helps power the facility’s lighting and HVAC system. And now, clean energy investments like this one are delivering another impressive benefit — real savings for residents in our service area.

On top of the Power Quality Facility at West Point Treatment Plant, 140 solar panels provide clean power for lighting, heating, ventilation, and air conditioning that keeps the batteries cool.

Through federal and local energy-efficiency incentives, clean energy projects at West Point earned King County $5.2 million in savings for the 2024 tax year. Those savings mean borrowing less money for critical upgrades, lowering long-term costs, and supporting King County’s Strategic Climate Action Plan goals.

The onsite battery system at West Point Treatment Plant provides reliable power to seven critical pumps. During its first year of service, it helped the pumps continue operating during 78 power disruptions.

The Inflation Reduction Act (IRA) brought in a large chunk of savings, with King County receiving $7.2 million in federal tax credits in total. The law, passed by Congress in 2022, allows public utilities to receive rebates for clean energy projects such as solar installations, electric vehicle chargers, and other upgrades.

The Wastewater Treatment Division received a large share of those savings with about $4.76 million. The funding is tied to investments placed into service in 2024, including our state-of-the-art battery system and the rooftop solar array in Seattle.

“We are thrilled that our infrastructure investments are paying off,” says Abby Hawley, senior sustainability specialist in WTD’s Sustainability Program. “Every renewable energy project and efficiency upgrade we make reduces our climate impact, and every dollar we save through rebates and efficiency helps reduce our costs.”

The 24,000-square-foot facility plays a critical role at the plant, especially during extreme weather. It provides reliable power for seven essential pumps and helps prevent disruptions when the electrical grid experiences a brief dip in power. In its first full year of operation, the system helped the 60-year-old plant ride through 78 power disruptions.

Through the IRA, we recovered approximately 30% of the installation cost for the facility’s battery and solar systems.

We also received a $577,000 rebate from Seattle City Light’s Commercial and Industrial Energy-Efficiency Programs.

Senior Operator Maria Hill monitors the oxygen generation building at West Point Treatment Plant.

This funding supported upgrades to the Oxygen Generation and Dissolution System or “OGADS” at West Point.

During the secondary treatment process, OGADS supplies oxygen to the beneficial bacteria that break down the remaining organic material in the wastewater. While the system is essential to the wastewater treatment process, it also demands a lot of energy, accounting for about one-third of the plant’s electricity use.

As part of the project, we replaced 24 mixers that blend oxygen into the wastewater. You can think of them as industrial-sized stand mixers.

This upgrade saves over 2.8 million kilowatt-hours of electricity every year the system runs.

“Upgrading these aging systems with modern technology helps us do the same work with less energy — and that adds up to significant savings over time,” says Carl Grodnik, who leads WTD’s Energy Program.

Every clean energy improvement helps us protect public health and the environment — while keeping costs lower for the people we serve.

Senior Operator Maria Hill looks up at the massive tanks that underwent media replacement as part of a recent oxygen generating and dissolution system (OGADS) upgrade project. The oxygen generated at the facility is mixed into the wastewater to support the beneficial bacteria that break down organic materials in the water.