Washington (WA) data center power coverage
Real, sourced large-load tariff and interconnection research on file for Washington — never inferred, never scraped, never implied beyond what's actually been checked.
Large-load tariffs
Seattle City Light (Washington), new large data center load contracts
ThresholdData center service of 10 MVA or more of capacity installed within any five-year period after January 1, 2027
StatusSeattle's 2027-2028 retail rates ordinance (approved July 22, 2026; some sections take effect Jan 1, 2027 and the data-center definition counts installations after that date) adds Seattle Municipal Code 21.49.059: new large data center load is not eligible for general service rates and must sign an individually negotiated Service Agreement. Required terms include a guaranteed minimum demand or service rating, metering at 600 volts or higher, power factor of 97% lagging or better, curtailment provisions, full upfront payment for infrastructure (feeder, transmission and substation upgrades), and full recovery of the cost of new power, transmission and ancillary services, with the customer staying responsible for agreements signed to serve it until the contract ends. Energy and demand are priced at the utility's marginal cost of new supply plus a service fee. Demand above the contract demand is billed at 300% of the demand charge. Contract term is up to 20 years. Service starts only after the contract is signed and the infrastructure, contracts and resources are in place.
Contract termNot stated in the filings we read
RampNot stated in the filings we read
Take-or-pay (minimum bill)A guaranteed minimum demand or service rating, set in each individually negotiated Service Agreement
CollateralNot stated in the filings we read
Exit feeNot stated in the filings we read
Notice to reduce or endNot stated in the filings we read
Time to powerNot stated in the filings we read
SourceSeattle City Council ordinance for the 2027-2028 retail rates (seattle.legistar.com, read in full, including SMC 21.49.059 and the 20-year contract authorization).
Grant County PUD (Washington), Rate Schedule 94 New Large Load
ThresholdNot stated: a New Large Load is defined in the District's Customer Service Policies (not read)
StatusLOWER CONFIDENCE. Grant PUD, which serves Quincy, says large power users, including data centers, pay for the added generation, transmission and distribution infrastructure needed to serve their loads (its data center FAQ page, read). The District's 2025 Rate Schedules 14 and 15 are reported to say that any load that qualifies as a New Large Load is billed under Rate Schedule 94 (seen in search-result text of those schedules, not opened). Rate Schedule 94 itself, the New Large Load threshold, contract terms, minimum bills, deposits and exit terms were NOT read: our fetch of the schedule returned page not found. The PUD reports about 800 MW of large-load requests waiting in its application queue and says it serves 8 data center operators using about 280 average MW in 2025, roughly 37% of the county's load. A March 2025 commission recap is reported to have set limits on new large-load growth until substation and transmission upgrades add capacity (search-result text, not opened).
SourceGrant PUD data center FAQ page (grantpud.org/blog/data-center-faqs, read 2026-10-17); search-result text of Rate Schedules 14 and 15 and the March 25, 2025 commission recap (not opened); Rate Schedule 94 not found.
Chelan County PUD (Washington), Rate 36 Data Centers and Similar Loads
ThresholdApplies to data center and similar loads; service is limited to 3 MW per service point
StatusLOWER CONFIDENCE (built from the PUD's published news and an industry summary; the rate schedule page returned an access error). Rate 36 has an upfront capital charge for substation and transmission, a security deposit of up to three months of estimated bills, interruptible service where other customers are served first, and an energy charge that moves from cost of production to market after the group of customers reaches 10 MW. Confirm current terms with the PUD before relying on them.
Contract termNot stated in the filings we read
RampNot stated in the filings we read
Take-or-pay (minimum bill)Not stated in the filings we read
CollateralSecurity deposit of up to three months of estimated bills (from the PUD's published news and an industry summary; the rate schedule itself was not read)
Exit feeNot stated in the filings we read
Notice to reduce or endNot stated in the filings we read
Time to powerNot stated in the filings we read
SourceChelan PUD news release on crypto and data center rates, August 2023; APPA coverage; the rate schedule was not read.
Snohomish County PUD (Washington), large-load review
ThresholdAny request above 2.5 MW is treated as a large load
StatusLOWER CONFIDENCE. As of May 2026 the PUD requires a System Impact Study for any request above 2.5 MW to find out whether power is available and which upgrades are needed, and it was serving no data centers. The county council adopted a six-month emergency moratorium on new data centers in unincorporated areas in late June 2026. No data center rate schedule was confirmed.
SourceHeraldNet and Everett Post coverage of the PUD's large-load planning (2026); the PUD rate book was not read.
Avista (Washington and Idaho), large-load service
ThresholdNo tariff threshold; the first deal is 125 MW growing toward 500 MW
StatusLOWER CONFIDENCE. Avista has no large-load tariff. It signed a non-binding agreement on May 29, 2026 with a data center developer in its Washington territory (125 MW from 2029, a path to 500 MW by 2032), subject to Washington UTC approval, then said on June 12 it would pause processing large data center requests while rules are developed. The Washington UTC is writing rules and a tariff for large energy loads. Avista says the customer would pay the added power supply, transmission and infrastructure costs. No Idaho tariff was found.
SourceSpokesman-Review, KXLY and Inlander coverage of the Avista agreement (2026); UTC rulemaking not read.
Interconnection & regulatory guidance
Washington — UTC large-load tariff docket (UE-260162), in progress
Contact guidanceWashington's large data-center presence is concentrated in public utility district (PUD) territory near federal hydro resources (e.g. Chelan, Grant, Douglas County PUDs), which the UTC does NOT regulate -- confirm whether a given site is IOU or PUD territory first, since this entry only applies to investor-owned utilities (Puget Sound Energy, Avista, PacifiCorp). For PUD territory, contact that specific PUD directly; several (e.g. Chelan PUD) are independently working through their own data-center policies.
ThresholdNo adopted numeric MW threshold yet -- the UTC's Data Center Workgroup has recommended one be set as part of a new rate class, but as of this research no specific number had been adopted.
ProcessThe Washington Utilities and Transportation Commission (UTC) opened Docket UE-260162 on April 7, 2026 to proactively address investor-owned utilities connecting large energy loads, including data centers, and hosted a hybrid technical workshop on April 27, 2026. The docket's own Data Center Workgroup has recommended the UTC develop a model tariff establishing a new rate class that: sets an MW threshold for what counts as a large load, specifies required load characteristics, requires large loads to pay for their own direct interconnection costs, and requires them to cover any generation/transmission/distribution costs their connection requires. This is an in-progress rulemaking docket, not yet a final adopted tariff.
SourceWashington UTC official notice (utc.wa.gov/news/2026/utc-host-technical-conference-large-energy-loads-april-27); Public Power Association coverage of Chelan PUD's own parallel data-center policy work (publicpower.org). Docket UE-260162's own filings not independently read in full during this research -- confirm current docket status directly before relying on specifics.
Land-constraint screening
Every Kill Test automatically screens against 6 nationwide land-constraint layers, Washington included — no state-by-state gaps here.
FEMA Flood ZoneNearby WetlandsProtected / Conservation LandCritical HabitatSeismic HazardTribal Land
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