Measure the grid you live on.
GridWitness turns the meters you already own — smart plugs, 3-phase meters, inverters, DIY PMUs — into a distributed, UTC-true measurement fabric for the GB grid. Four professional PMUs cost thousands; four hundred amateur nodes cost nothing and cover the whole island.
Default is anonymous and frequency-only. Every step beyond that is your explicit, revocable choice.
Frequency is global
The grid frequency is the same for everyone at a given instant. Any node can measure it, and on its own it's genuinely useful — with zero information about your household.
Density nobody else has
We don't replace professional PMUs — we build the thing nobody has: geographic breadth. Many cheap nodes plus a few GPS anchors map the whole network.
Privacy is the deal
We ask for the least revealing thing that's useful, and never bundle the sensitive channels. Consent is per data-type and location is tiered — always reversible.
How it fits together
A Home Assistant integration (or your own uploader) reads the meters you already have.
Sign up here, pick what to share, and get a key that registers your node.
Batches stream over HTTPS to ingest.twinscrollgridbalancer.co.uk, UTC-corrected and deduplicated.
Anonymised, derived-location data feeds grid research — never your address or token.
Ready to put your meter on the map?
Create a free account, issue an API key, and start contributing in minutes.
Get started