I would contend otherwise, that offers the potential to use 3.25 units per hour, with there being 24 of those every day. Seventy eight at a modest 25.6 per unit charge gets us to £20.We are not wasteful with electric. Indeed it is difficult to be with 16 / 10 amp (or lower) trips on the pitch.
Of course not realistic with any reasonable people.
However, we have witnessed a hybrid being plugged in when dark on a CS, each evening. Hopefully, they had arranged with the site owner to do so.