HB1921 – Creating rules for the tax assessment of wind and solar facilities, and authorizing counties to enter into agreements for their annual payment of fees in place of property taxes.
Prime Sponsor – Representative Ramel (D; 40th District; Whatcom County) (Co-Sponsors Boehnke & Young – Rs; Fitzgibbon, Shewmake, & Kloba – Ds)
Current status – Had a hearing in Finance January 18th; replaced by a substitute from the prime sponsor making a number of changes that are summarized in a staff memo and passed out  of committee February 4th. Referred to Rules February 7th. Replaced on the floor by a striker from the prime sponsor which stripped the bill down to the development of rules for assessment by the Department of Revenue and required county assessors to refer to those in valuing renewable property, though they’d still be allowed to use other methods if they had a compelling reason. Passed by the House 97-1 on February 15th.
Next step would be – To the Senate.
Legislative tracking page for the bill.

Summary –
The bill would require the Department of Revenue to develop rules for the tax assessment of solar and wind facilities of at least one megawatt of AC nameplate capacity that were not yet in service, using a cost-based approach. In doing this, it would have to develop industry specific trending tables for solar and for wind projects, and to develop an appraisal model in cooperation with stakeholders within 90 days of the effective date of the bill. The bill would prohibit revaluing a facility for at least twenty years after it was placed into service.

It would also allow the governing body of a county and the owner of the property for a wind or solar project in the unincorporated area of the county that was not yet in service to enter into an agreement exempting it from the property tax and providing for the payment of an annual fee in its place. The fee could not be more than $4,500/MW of AC nameplate capacity for a solar project and $8,000/MW for wind projects, plus $750/MW for storage associated with projects. Agreements would be limited to a maximum of ten years, but might be renewed by mutual consent. If any portion of the property were within an incorporated city, the county would have to have its consent to an agreement. The payments would be due on April 30th each year, and handled as if they were property tax payments. If the fee weren’t paid, the property would be subject to the regular tax the next year, though it could continue under the agreement by paying the fee plus penalties and interest by October 31st of the year in which it was due.