Oh, I did get an email too:
Spontaneous Saving Session Alert! You'll earn 1800 OctoPoints – that's £2.25 worth – per kilowatt hour for any electricity you cut down between 6:30 PM and 7:30 PM on 15th March. That's right, the Saving Session is TODAY.
Opt in now on your dashboard. You'll go into a draw to win our extra big Spot Prize: 800,000 OctoPoints – that's £1000 worth! – just for opting in.
On top of that, we've got an extra challenge for this spontaneous Session: cut down even more power to earn our Super Saver Bonus. The top 20% of Savers in this Session (i.e those who reduce the highest % of their normal power use) will each earn an extra 1,000 bonus OctoPoints – worth £1.25.
Why have I only found out about this Saving Session on the day?
Saving Sessions is all about proving people can come together to balance the grid and avoid fossil fuels.
We don't always get much notice when the grid needs help, so to make sure Saving Sessions can work at a big scale, we really want to find out how readily people can get involved in a Saving Session with different amounts of notice.
That's the reason for the short notice. Don't worry if you don't get to opt in in time – this Session won't impact any streaks you've been building up.