Soldato
So, I'm now with Octopus....
Tarrif is a touch cheaper than I had with Shell so that's a good start..
How do they work out all of their energy comes from green sources though, I'm pretty sure it all just ends up in the grid and goes through the same cables, its not like someone reconnects you on the pylon down the road when you switch...
If you're on a tariff which says it's green then they promise to buy in/generate as much green energy as you use to the grid. You're correct it's otherwise just grid mix you actually use.
Did you use a ref code? it's not too late even after you switch over if you forgot or didn't realise. Worth it for £50 ref money.
I'd recommend moving to the tracker tariffs perhaps, on balance should wind up cheaper than the standard flex/SVR plan.