Ok, so it seems I opened a bit of a can of worms with my gimmick comment
The reason I said, and stand by, that is I honestly don't think any meaningful sway of people's usage habits will ever be achieved by saving sessions, free energy sessions or anything else that has the vast majority of people looking at the results afterwards and saying "is that it?!"
I had a decent stab at the energy saving sessions over winter but the reality is I have a young child and a pretty fixed routine with a 9-5 job when I'm in the office. Obviously my savings were never going to be great but I saved a whopping 1.8kWh. pretty rubbish right? Well apparently that put me in the top third of savers. It was a bit of interest for the 14 sessions and because it was a new thing that 1.8kWh was paid at a pretty unsustainable rate of £2.72 / kWh in 'Octopoints'.
Take that last free energy session as a further example in terms of load shift. You aren't going to be cooking your dinner in the early afternoon. It wasn't really long enough to do your laundry (my washing machine takes 2:40 to do a cycle that uses 1kWh so in an hour I'd save maybe 0.5kWh as the heating is front loaded). Which really leaves home battery storage people and EV owners. I await to be proved wrong but home battery storage is a TINY proportion of the population so that leaves EV owners as the masses. It seems to be commonly accepted that people with EVs are generally on an EV tariff so while you could look at that 7kWh or so you shoved into your car, if you happened to be at home during business hours on a week day, as 7kWh of peak rate electric but it's real 'worth' to you was actually about 50p. People aren't going to go out of their way for 50p sporadically placed here and there long term.
I honestly think that Octopus's beta testing and data accumulation (because lets face it, that's what it is) would be better targeted to those that want and have the ability to game it. Make it uber nerd, make it SETI for power distribution, gamify it with league tables and willy waving. Target it and exclude people like me who have a half arsed stab at it and then scoff at saving 20p. That will give a true indication of what is possible without the noise of having to calculate whether the likes of Rob from Norwich was watching the clock tick by before switching his oven on at 7:00 instead of his usual 6:55.
I think it's absolutely fantastic that we are in a situation where renewables are so abundant that at times we simply don't know what to do with the energy. It also represents a huge waste and a huge opportunity.
Those with battery storage may be able to make a bit of money from doing the pump and dump at optimal times but what percentage of the population is that?
V2L has been mentioned and that would bring home battery storage to an ever increasing number of people. V2G would be even better but is it anything more than a pipe dream at the moment?
The Nio esque battery swap stations could have been grid connected battery storage with demands from both sides forecast and helping balance the difference. It was never going to happen though because it needed a holistic approach and it's much easier (and likely better business sense) for every manufacturer to do their own thing and the public charging solution is 79p / kWh live off the grid* while you eat some crap and drink an overpriced coffee.
*Yes before you say it... some of the Gridserve sites are more forward thinking than that and have their own storage but I think their future business model is pretty clear now.
So I'm not knocking the vision, I'm knocking the approach as I can't see the longevity in it without infrastructure to back it up. I think trying to shift peak demand is like trying to push water up hill (energy storage pun absolutely intended) but shifting peak availability and spreading it out a bit... that has legs.
EDIT - I said V2L but really I meant V2H because I mixed my terminology up