Up here in the north of Scotland we have a slightly unusual tariff called Total Heating Total Control. It is a two rate, two meter tariff, but unlike E7 you can have 24/7 access to the cheap rate. Sounds too good to be true? Well the catch is that you are only allowed to use the cheaper meter for heating appliances, and your home must have a certain proportion of storage heating. The electricity company will energise the storage heaters at times of their choosing, based on weather forecasts.