Seattle City Light’s Upcoming Time of Use (TOU) Rates

Seattle City Light will introduce a Time of Use (TOU) rate in 2025, giving customers a new way to manage their energy use and lower their bills.

To help you understand how this will work, we asked the TOU team to explain the basics of TOU rates and how they can benefit your household and the broader community.  

Q1: What are Time of Use (TOU) rates? How do they work?  

Time of Use rates are electricity prices that change depending on the time of day you use energy. They’re designed to reflect fluctuations in demand. The cost is lower during off-peak hours, when demand is lower, and higher during peak hours, when demand is at its highest.  

For example, If you run your dishwasher at 12 a.m., during an off-peak period, it will cost less than running it at 6 p.m., during peak hours. This new rate system gives you more flexibility to save money by making small adjustments to when you use electricity.  

It’s about more than saving money, though. Using energy during off-peak hours can also help balance demand on the power grid, which helps contribute to the energy system.  

Q2: Why is Seattle City Light introducing a TOU rate?  

We’re offering a TOU rate for a couple of key reasons. First, it’s about providing options. TOU pricing gives customers new ways to control their energy bills.  

Second, it’s about making the grid more efficient. When we shift some energy use to off-peak times, it reduces strain during high-demand periods. That makes the system more reliable and helps us avoid investing in costly new infrastructure.  

Finally, it aligns with our energy goals. When demand is spread more evenly, it’s easier to rely on clean, renewable resources, such as solar and wind, which can have varying availability throughout the day. This pricing system is part of a long-term plan to create a more sustainable energy future for our communities.  

Q3: What are the peak and off-peak hours?  

We will be using a three-tiered peak system for our Time of Use rate: peak, mid-peak, and off-peak. The price you pay for electricity will depend on when you use it. Here are our TOU hours:

• Peak hours are when electricity is most expensive. This will be from 5 p.m. to 9 p.m., Monday through Saturday, except on city-observed holidays. This is when demand is highest, as people are typically settling in after work and school, running appliances, charging cars and devices.
• Mid-peak hours will be from 6 a.m. to 5 p.m. and from 9 p.m. to midnight, Monday through Saturday. On Sundays and city-observed holidays, mid-peak pricing applies all day from 6 a.m. to midnight (with no peak hours).
• Off-peak hours are when electricity is lowest. This will be from midnight to 6 a.m. every day.

In general, peak electricity rates are twice as high as off-peak rates, with mid-peak pricing being 1.75 times as high as off-peak. If you can shift some of your energy use, like running appliances, to mid- and off-peak times, you can save money.

Q4: How are TOU rates calculated? How do they compare to flat rates?  

City Light currently uses flat rates, which charge the same price for electricity regardless of when you use it. While simple, flat rates don’t account for how electricity production and delivery costs rise and fall throughout the day.  

TOU rates, on the other hand, have time-based pricing. They’re calculated based on: 

• The cost of generating and distributing electricity at different times of day. 
• Demand, which spikes during peak hours 

When demand is high, it costs more to produce and deliver electricity, so peak hour rates will reflect that. During low-demand periods, production costs drop, and so do rates.

For many customers, switching to TOU rates can mean savings with just a few easy adjustments, like running appliances or charging electric vehicles during off-peak hours.  

A brighter energy future  

TOU rates can give you more control over your electricity costs while supporting a more reliable and cleaner energy system. This is an exciting step for Seattle as we move toward a greener future.  

Stay tuned for more updates as the rollout approaches in 2025. For now, start exploring how you can adjust your energy use by creating an online account at the Utility Services Website.

If you’d like to stay informed about TOU, sign up here to receive email updates on Time of Use rates. Get ready for a brighter, more sustainable tomorrow!