You'll earn OctoPoints per kilowatt hour for all the electricity you don't use compared to normal. There'll be at least 12 Saving Sessions this winter (but likely many more), and they'll be between one and four hours long.
It's hard to say exactly how much you could earn overall, because it all depends on a lot of factors we can't totally predict: from how many Sessions there'll be to how long each one is to how much National Grid will pay in each Session.
Plus, there are individual factors, like how many you choose to get involved in, and how much power you're able to save in each one.
A lot of the unknowns exist because this project is designed to help balance the energy grid, and we don't know exactly how much help it'll need this winter - as that depends on stuff like the weather, energy demand and supply issues (for example, particular generators not running.)
If you managed to take part in all 12 Sessions and you saved 1 kilowatt hour on average per Session, we'd expect your OctoPoint rewards to be worth around £36. However, it's really likely there'll be many more than 12 Sessions. Based on previous years, we're expecting around 1 or 2 Sessions per week, so around 25 in total - if that happened, with a slightly higher average incentive, you could end up earning OctoPoint rewards worth around £100.