Thanks for your reply but comparing with ecnomy 7 doesn`twork. my 7hour off peak meter units cost less than econ 7 and the standard meter units cost less than daytime econ 7 but more than standard tariff units with some other providers. I also have to pay a daily standing charge on the off peak meter which makes it even more complicated!

I am unable to compare tariffs from different providers as I have two separate electric meters. one is only for storage heaters and the other for everything else.Can anyone help?