Energy systems · Morning Signal · 2 September 2026
The grid is becoming a software problem
Britain does not have a shortage of turbines. It has a shortage of machines that can listen to the network in real time — and a political class still photographing the postcard.
Stand on a service vessel in the North Sea and the story looks finished: white columns to the horizon, a country that learned to bolt steel to the seabed. Open the constraint-payment register and the story starts again. Power is being turned down because the wires, the substations and the market code cannot yet hear the weather as fast as the weather arrives.
That is not a failure of engineering romanticism. It is a software and market-design story that happens to involve 400-kilovolt kit. Demynex has spent the summer reading NESO papers, Elexon circulars and a stack of digital-substation tenders. The pattern is consistent: the scarce resource is no longer a rotor. It is an agreed way for a battery in Fife, a factory in Scunthorpe and a wind farm off Dogger to speak to the same clock.
Listening machines
A digital substation is a dull phrase that hides a change of genre. Instrument transformers and copper marshalling become sampled values on a fibre. Protection settings become code that can be versioned, audited and — if you are careless — remotely wrong. The operators buying this kit are not “doing AI”. They are trying to run a network whose generation fleet now has the manners of a mood.
The news, for a UK desk, is who gets to write the interface. If the listening layer is a patchwork of proprietary stacks, flexibility markets will keep paying the same few assets that already know how to talk. If it is a published standard with a test harness, a Midlands manufacturer can sell a box into a national market. That is industrial policy hiding in an IEC number.
Generation is the postcard. Constraint payments are the plot.
What to watch in 30 days
- The next NESO note on connections reform — not the headline queue number, the treatment of storage as a listening asset.
- Whether a regional distribution operator actually awards a digital-substation lot to a supplier that publishes its data model.
- Any ministerial speech that still measures progress only in gigawatts installed. That tells you the software problem has not reached the podium.
Sources: public NESO and Elexon material, contract notices, and reporting from the Demynex energy desk. This is journalism, not investment advice.