Seattle City Light bills are on a clear upward path. The utility's own strategic-plan projections show rates roughly doubling from a little over 10 cents per kilowatt-hour in 2019 to more than 20 cents by 2031, with 7 to 11 percent increases stacking up every year toward the end of the decade.

The strategic plan's retail electricity rate projections run from 2019 through 2032, with annual increases of 7 to 11 percent beginning in 2029.

City Light is owned by the city, so every dollar it costs to run the utility eventually gets spread across customer bills. Its public rate filings and bond disclosures, along with Seattle Times reporting, detail those expenses and closely track the utility's projections. The total cost of running City Light is projected to climb from about $1.2 billion a year to roughly $2.2 billion a year by 2032, pushed by the same two forces utilities nationwide are wrestling with: more demand for electricity, and an aging grid that needs substantial investment.

That total, called the utility's "revenue requirement," rises from about $1.2 billion in 2026 to about $2.2 billion in 2032. It covers capital spending, operations and maintenance, and power costs.

On the demand side, electric vehicles, electrified building heating and cooling, and data-center growth are all increasing electricity use. With less cheap surplus hydropower available as a cushion, City Light has to purchase power to meet that growth: about $240 million a year by 2032 for new wind and solar, plus another $150 million a year to the Bonneville Power Administration, the federal agency that controls roughly three-quarters of the region's transmission lines and distributes power from the federal dams on the Columbia River. That demand forecast was finalized before the city's one-year moratorium on new data centers. Under a separate City Light rate plan, new data centers must now cover the full cost of their own power. Data centers already on the grid are exempt; the rule applies only going forward.

City Light's electricity demand projections span 2025 through 2035, with EVs, building electrification, and data centers accounting for much of the expected growth.

New power resources and higher payments to the Bonneville Power Administration account for the added spending; the agency "wheels" power and transmission capacity to the region.

The other half of the bill is the grid itself. City Light plans to spend $200 million a year by 2032 on reliability work. Replacing aging underground cable is the single biggest expense, at about $2 billion over the next 15 years. Some of that cable went underground downtown for practical reasons; a lot of it went underground in wealthier neighborhoods purely for appearance's sake, and every ratepayer in the city is now splitting that bill, a pattern The Seattle Times has traced back to 1960s-era decisions. Two other expenses each add roughly $100 million a year by 2032: inflation and the utility's relicensing of its Skagit River dams, which includes new fish-passage requirements.

City Light separates its expenditures into "O&M," for day-to-day operations and maintenance, and "CIP," for capital improvement spending. The latter covers building and repairing infrastructure.

Lower-income households can qualify for substantial discounts through the city's Utility Discount Program: 60% off their electric bill and 50% off sewer. Eligibility extends to anyone making less than 70% of Washington's median income, about $51,000 a year for a single person or $98,000 for a family of four. Beyond those discounts, the dispute is over who carries the remaining costs. Residential customers made up only about a third of City Light's 2025 power use; commercial and industrial accounts took in well over half.

The 2025 breakdown puts commercial and industrial use at 55.7 percent and residential use at 32.6 percent. Other utilities accounted for 8 percent, and City Light's own operations used 3.7 percent.

City Light doesn't publish a full customer list, but its own bond disclosures name the ten biggest accounts by dollars billed in 2025: the University of Washington topped the list at $40.9 million, followed by the steel manufacturer Nucor at $30.7 million, Sabey Corporation's data centers at $18.3 million, Boeing at $17.8 million, and Amazon at $17.0 million, with King County, the City of Seattle, the U.S. government, and a handful of other large accounts rounding out the rest.

Those billing rankings put the University of Washington, Nucor, and Sabey Corporation at the top of City Light's ten largest customer accounts for 2025.

The policy question is how to divide the cost of new power between households and the commercial and industrial customers that use most of the electricity. A targeted consumption tax, or a cost-allocation formula that treats cheap legacy hydropower differently from newly purchased power, would shift more of that expense to commercial and industrial accounts, easing the burden on households already squeezed by rent and grocery bills. The City Council still faces a choice between that approach and allowing the increases to land evenly across every meter in the city.