Harmignies Energy Storage
In Elia’s schedule, start not announced, 75 MW · 300 MWh, in Mons, owned by Energy Solutions Group. Every fact below is as a published source states it, with the address beside it; a field not shown is one no source gave, and nothing is guessed.
The battery
| Power | 75 MW |
| Capacity | 300 MWh |
| Duration | 4.0 hours |
| Status | In Elia’s schedule, start not announced, as of 19 October 2026 |
| Owner’s date | 2025, expected by the owner in the fourth quarter of 2025 |
| Municipality | Mons, Harmignies, Hainaut |
| Grid connection | Elia, the high voltage substation beside the site |
| Placed on the map | at the site itself, as mapped on OpenStreetMap (Harmignies BESS) |
Who is behind it
| Owner | Energy Solutions Group |
| Ultimate owner | Patronale Life (majority) |
| Built by | Tesla (82 Megapack 2XL) |
Not published anywhere we have found: developer, traded by. The page says so rather than guessing.
In Elia’s list
Elia schedules this battery under the name below. Elia usually starts scheduling a battery when it begins testing, so the first day here is when it reached the grid, not when it began commercial operation.
| Elia’s name | First listed | Last listed | Power, as Elia lists it |
|---|---|---|---|
| Harmignies Energy Storage BESS | 1 September 2025 | still listed | 75 MW from 1 September 2025, then 76 MW from 8 January 2026 |
Elia Transmission Belgium, open data dataset ods179, Elia Open Data Licence.
What the sources say
Elia has scheduled it since the start of September 2025, at 75 MW and then 76.3 MW. No release found from the owner saying it has started commercial operation. The newest pages found still describe it as being built, due in autumn 2025.
Evidence and sources
- owner: energy-storage.news/construction-starts-on-440mwh-of-tesla-bess-in-…
- position: openstreetmap.org/way/1491083900
From the owners’, developers’ and builders’ own releases and the trade press, read by Vitreous, joined to Elia’s list by name. This page carries no money: no Belgian body publishes what a named battery earns. List id BE-B08.