dnos.org
DNO is standard sector shorthand in the UK and several other markets for distribution network operators, the regulated companies running local electricity grids. An organisation, platform or association serving them would find the letters already in circulation among its audience.
DNOS equally reads as a network operating system, a distributed OS, or DNS-adjacent infrastructure, all of which put it firmly in the technical world where a compact four-character name belongs.
On the .org the association and standards readings are strongest. Technical bodies, open-source projects and industry groups all use that extension, and a short name suits a body whose full title nobody says aloud.
Four characters, no hyphen, no digits, looking like a system component, which for a technical buyer is the right first impression.
The name is listed for sale. Offers considered.