> Is that counted as generation in these stats? Or is it just manifested as reduced demand?

Probably _mostly_ as reduced demand, though if you net feed back into the grid then that may be counted as generation.

It's estimated that embedded generation - behind-the-meter solar and batteries, CHP, and diesel generators used for backup or to avoid peak pricing - was about 23% of the UK's total capacity in 2024, and almost certainly a little higher now.

https://www.neso.energy/energy-101/electricity-explained/how...