Avista 2025 ALL-SOURCE REQUEST FOR PROPOSAL

Avista Corporation, serving 418,000 electric and 382,000 natural gas customers across Washington, Idaho, and Oregon, seeks electric resources to meet incremental capacity needs identified in its 2025 Electric Integrated Resource Plan. The All-Source RFP welcomes proposals from all developers, landowners, energy companies, government agencies, tribal authorities, and demand response providers.

Avista's identified resource needs include: 105 MW between 2027-2030 plus 310 MW of winter capacity by 2029 (up to 415 MW total); 135 MW between 2027-2030 plus 290 MW of summer capacity by 2029 (up to 425 MW total); and up to 200 aMW of renewable or non-emitting resources subject to pricing and demand. Demand response proposals may begin as early as 2026. Generating resources must have minimum 20 MW capability, though demand response proposals of any size are considered. Avista prefers long-term resources (20-year PPAs preferred) but will consider shorter durations if cost-effective.

Eligible resource types include renewable energy (solar, wind, hydroelectric, biomass, geothermal, clean hydrogen meeting RCW 19.405.020), energy storage (lithium-ion, iron oxide, pumped hydro, and other technologies), conventional generation and tolling agreements (natural gas, nuclear, firm contracts), and demand response programs. Avista will consider various structures: Power Purchase Agreements, turn-key/Build-Transfer ownership, joint development, or co-ownership arrangements. Proposals from minority, women, disabled, and veteran-owned businesses are encouraged.

Projects must include detailed interconnection and transmission plans to ensure deliverability to Avista's service territory. The RFP aligns with Avista's 2025 Interconnection Cluster Study timeline, with Phase One interconnection cost estimates available for bidders by Detailed Proposal stage. On-system resources must demonstrate participation in past, current, or planned cluster studies, though non-participation does not automatically eliminate proposals. Bidders may request Network Resource or Energy Resource Interconnection Services under Avista's Open Access Transmission Tariff. Transmission capacity availability by location ranges from 0 MW (Mid-C Washington) to 268 MW (Montana) as of May 1, 2025.

Key dates: Bidder's Conference June 6, 2025 at 10:00 AM Pacific Time; Initial Proposals due June 30, 2025 at 5:00 PM Pacific Time; Price refresh deadline August 21, 2025; Short-list selection by September 1, 2025; Detailed Proposals due October 6, 2025 at 5:00 PM Pacific Time; Second price refresh due November 10, 2025; Finalists selected December 1, 2025; Negotiations commence January 2026; Agreements completed by May 30, 2026; RFP Compliance Filing with Washington UTC by August 28, 2026. Executed Confidentiality Agreements (Exhibit A) must be submitted by June 30, 2025.