Virtual battery is not based on prices. You give them kWh, you can get kWh back (but you pay distribution fees).
Discussion
I am just using argument of guy from Signal group you are member probably too.
If it's in your contract, then you are fine.
Wish Australia had "virtual batteries"!
Instead we just have a regulated feed-in rate, and the grid supplier retaliates by charging higher supply charges for customers who have solar.
I don't sell any of my surplus. F--- those monopolists. My BIL was selling back to the grid, until we ran the numbers and found it was actually cheaper not to.
Euroland has a lot of stupid in its regulatory systems, but less outright fraud.