Economy 7 advice needed

[Manfred Jarvis]

I am asking on behalf of a friend who has an outbuilding that he uses as an art studio, the building is fully insulated and is currently heated by 3x 2kw convector heaters.
The problem is that his heating electric costs are very high using standard daytime tariff, so I suggested to him, why not install storage heaters. This way the studio will always be warm, and the heaters will charge up during off peak cheap rate costs.

My question to you here is this...

There is only one 10mm armored SWA cable going from the house to the outbuilding, and to lay a second cable for timed on/off of storage heaters would be very impracticle.
So Is it possible to have an economy 7 tariff while keeping his existing smart meter and simply adding a time switch to each storage heater locally by the heaters to switch them on only during cheap rate between midnight and 7am, so they can be wired up to the existing outbuilding supply which would be permanently live with an E7 tariff?

Also does anyone know if he can have an E7 tariff, without having storage heaters as he tends to be a night owel and uses more electricity at night. But he will want to buy storage heaters later on.

I know some suppliers wont give you an EV tarrif if you don't own an EV, so does the same apply to storage heaters ?

 

[Avo Mk8]

He can apply for an E7 tariff with or without storage heaters.
It depends on his electricity usage profile on whether this is a good idea or not.
The whole house will be on E7 midnight to 7.00am (or whatever), so if thats when he's using power he will save straight away! But the downside is that peak rate is more expensive.
So there are sums to be done. I can't remember the stats, but I think you need at least 30%, maybe more of you total daily demand to be cheap rate for this to be worthwhile.