(Exact name of registrant as specified in its charter) Delaware 001-41617 36-5047383 (State or other jurisdiction of incorporation) (Commission File Number) (IRS Employer Identification No.) 6200 Paseo Padre Parkway , Fremont , California 94555 (Address of principal executive offices) (Zip Code) Registrant’s telephone number, including area code: (510) 270-2500 Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2.

Strengthening Solar Product Portfolio and Market Footprint • Extends addressable market with four new product lines, expanding reach across 15 additional countries, and access to large, legacy customer base • Strong, established go-to-market channels expected to facilitate incremental demand for Nextpower product portfolio including trackers, eBOS, PCS, and BESS • Business expected to contribute approximately €300 million in revenue and €45 million of adjusted EBITDA on an annual run-rate basis following transaction close, and is expected to be accretive INTERSOLAR EUROPE 2026, MUNICH, Germany, June 22, 2026 — Nextpower™ (Nasdaq: NXT), a leading provider of solar and power technology solutions, today announced it has entered into a definitive agreement to acquire Zimmermann PV-Steel Group, a Germany-based solar technology provider with more than 20 gigawatts (GW) deployed and deep market presence in Germany, one of Europe’s largest solar markets.