The Seattle City Council recently approved Seattle City Light’s new Integrated Resource Plan.
"This is an important milestone for the utility and our customers who depend on reliable, clean, and affordable electricity. The IRP helps us understand the evolving energy landscape and serves as a roadmap for how we’ll sustainably and reliably meet demand over the next 20 years," Seattle City Light said.
Washington state law requires electric utilities to file an IRP report every two years (alternating between a full report and progress report), "but the IRP is much more than a regulatory requirement," the public power utility noted.
"It’s a core planning tool that helps us prepare for rising energy demand and secure reliable, clean, and affordable power for the future. The IRP process includes public outreach and stakeholder engagement to reflect our commitment to transparency and community involvement."
To build the IRP, "we model different scenarios to reflect how energy use may shift in the future. Changes in the weather, new technology, population growth, and shifts in how homes, businesses, and vehicles use energy all affect our future load or energy need. The IRP explores what kinds of power resources we’ll need to keep the lights on for decades to come," Seattle City Light said.
Electricity demand in the region is increasing. "More people are moving to the area, demand for electric vehicles is increasing, and more homes and businesses are using electricity for heating and cooling. These changes are good for the environment, but they also put pressure on the grid, especially during cold snaps or heat waves," the utility noted.
Seattle City Light said that recent studies warn that the Pacific Northwest could face energy shortages during extreme weather, and planning ahead is critical to keeping its system reliable.
The 2026 IRP confirms what the utility saw in its 2024 IRP progress report: "We will need a significant amount of new energy resources."
Seattle City Light said the following are the key takeaways:
- Customer energy needs are growing. "We expect electricity use to keep rising over the next 20 years, especially during winter peak hours."
- The utility needs new, clean power sources. "Today, about 75-90% of our energy comes from hydropower. To support future growth, we will need to add new resources like wind, solar, batteries, and improved transmission lines to reliably meet demand."
- Extreme weather is adding new pressures. Winter cold snaps and summer heat waves make it harder to keep supply and demand in balance. Drought conditions can also reduce hydropower production.
- New technologies will play a key role. To support reliability, future studies will explore firm energy options like enhanced geothermal energy, hydrogen, long duration energy storage, and small modular reactors.
- Conservation is still essential. Saving energy remains one of the most effective tools we have. Between 2026 and 2035, we plan to achieve more than 100 megawatts of customer-side programs, helping reduce strain on the grid and lower customer costs.
Engaging with community
"Our success depends on the active participation and support of our communities. We gather valuable input through public meetings, surveys, and other collaborative efforts," Seattle City Light said.
This feedback from community members, advisory groups, and subject matter experts helped shape the 2026 IRP, and their contributions improved the utility's forecasts and helped it align its plans with community priorities.
Looking ahead
"Technology, customer needs, and the energy landscape are changing quickly across the entire region. New growth, industry, and rapid electrification will continue to shape how much energy we need and when we need it," it said. That’s why the IRP is not a one time project. We update it every two years to make sure we are planning responsibly and preparing for a clean, reliable future."
Seattle City Light said it is committed "to leading the way as our energy system evolves. Our 2026 IRP is a strong, forward looking foundation to help us meet the challenges ahead and support a sustainable energy future for all our customers."
