I’m with Intelligent Octopus Go, and it works really well with my Zappi & Eddi. All car charging, domestic water heating and dish washer was using off peak rate. On high solar generation days Zappi & Eddi automatically take surplus generation.
Just had GivEnergy AIO batteries installed and now only use off peak charged power from grid or no purchased power at all. Two days ago we didn’t need to draw any power from the grid as our solar powered our house, hot water, EV and batteries. Wonderful! Just need to lobby in order to reduce standing charge