How do I power in slab heating?

I have 3 phase grid connection, on phase powers four 4.5kW slab elements. Other phases power the house including 2 A/C units. Last year Origin replaced our analogue meter with TOU Interval meter. Consumption has almost doubled to 21.09kW but no new electronics in house.

Looking to cut costs by dropping off-peak supply to slabs all together, moving it to new solar installation. The offpeak controlled load now barely heats the two slabs during the week, dumping power on weekend. All slabs are turned off as soon as things warmup. Are there suppliers who can design a solution, switching slab phase back into the house for summer & back for winter.

@BrownBird

21kWh is actually not very high considering you have in-slab heating and 2 x AC units. Why was your meter upgraded? Did you have solar installed?

Why is your bill showing before and after the solar/meter installation.

Slabs weren’t energised in the last bill. Only use one of the A/Cs this year. Have had solar installed for years, swapped it from gross to one of the phases when the .60 cents ran out. They changed it while I was away, against ‘my explicit wishes’. I was treating the grid as a battery, very cost effective, ran the household ex-slabs on solar during the day and drew from the grid of an evening. Having swapped the analogue meter for digital same utilisation on my end, but double utilisation via the ‘smart meter’…