Octopus in the UK has tariffs where it basically takes over your system (ie the batteries in particular) and subsumes them into its wider activities, eg: https

Octopus in the UK has tariffs where it basically takes over your system (ie the batteries in particular) and subsumes them into its wider activities, eg: https://octopus.energy/intelligent-flux-faqs/ https://octopus.energy/intelligent-flux-faqs/