Lund Hill Solar: what the state's largest array actually delivers

Nameplate is a promise, not a reading

Every solar project carries a nameplate capacity, the maximum power it can push out under full midday sun, measured in megawatts. Lund Hill's nameplate is on the order of 150 megawatts, per Avangrid Renewables' project page. That figure is real, but it describes a ceiling the array touches only for a few hours on the clearest days, not a level it holds around the clock.

The number that tells you what the array delivers is the capacity factor (the share of that nameplate an array actually produces averaged over a year). Utility-scale solar in the Pacific Northwest runs lower than in the Southwest, roughly a fifth of nameplate over a full year by the ranges the U.S. Energy Information Administration reports for the region. A south-facing slope in the Gorge does well in July. In a wet December, when the Cascades are socked in and the sun clears the ridge for only a few hours, the same panels produce a small fraction of their summer output.

The honest math across a wet season

Put rough numbers to it. An array of about 150 megawatts running at something on the order of a fifth of nameplate over a year would deliver roughly 250 to 300 gigawatt-hours annually, enough to cover a meaningful but modest slice of Avista's Washington load. We hedge those figures on purpose: actual output depends on the year's cloud cover, panel degradation, and how often the array is curtailed (told to stop producing because the grid cannot take the power), and the verified annual total lives in federal generation data, not a brochure.

The seasonal shape is the part a ratepayer should hold onto. Solar in Washington peaks in summer, exactly when hydro is also strong and demand for air conditioning stays lower than in hotter states. It bottoms out in winter, when the state's heating-driven demand peaks and the days are shortest. That mismatch is why no one credible claims one array replaces a dam, and why the state's plan leans on a mix of wind, solar, storage, and existing hydro rather than any single resource.

Who owns it, who buys it, who signed off

Lund Hill was developed and is owned by Avangrid Renewables, a company that builds and operates wind and solar across the country. The energy and the associated renewable credits go to Avista, the Spokane-based utility that serves much of eastern Washington, under a long-term power purchase agreement (a contract where a utility buys a project's output for a set period rather than building the plant itself). The arrangement lets Avista count the clean energy toward its Clean Energy Transformation Act obligations, the 2019 law that requires 100 percent carbon-free electricity by 2045, without owning the array.

Approval did not run through the state's big-project siting council. Klickitat County permitted Lund Hill at the local level, through its own planning process, which is why the most detailed public record of the project's footprint and conditions sits in county files. Transmission is the Bonneville Power Administration's world: BPA operates most of the high-voltage grid in this part of the state, and how much Gorge solar and wind the system can carry is an ongoing question rather than a settled one.

Worth watching this month

1. Avista's integrated resource plan filings at the Washington Utilities and Transportation Commission, where the utility shows how projects like Lund Hill fit its path to 2045, are worth checking for updates and tend to move slowly.

2. The U.S. Energy Information Administration's monthly plant-level generation data will show Lund Hill's actual output as the wet season sets in, published on a lag of roughly two months.

3. Klickitat County planning records remain the place to watch for any change to the site's permit conditions or for new solar applications nearby, mostly routine but occasionally consequential.

4. Bonneville Power Administration transmission notices decide whether more Gorge solar and wind can reach the wire, a routine-looking process that now and then shapes real projects.

5. The state's Clean Energy Transformation Act implementation at the Department of Commerce and the UTC is the slow backdrop here, worth a periodic look rather than a weekly one.