Classic UK government... Produce a 30 page document reviewing energy trends, but fail to mention the key element that led to reduced demand in that period ... Price!
The energy price increased 900% for gas spot prices. 600% for day ahead electricity prices.
Anyone commercial who hadn't bought the right long term contracts was forced to shut down.
When a good chunk of factories shut down, of course demand falls. And yet the report mentions frequently the 'recovery from covid' in an upbeat way, but never the massive price increase causing lots of industries to just shutdown.