Storage heaters do have excessive running costs. I have them in my flat despite there being gas available. I'm in a housing association property incidentally. I would never have accepted the move to this property had the housing association been honest about the running costs. My utility bills more than doubled in price after the move.
I personally don't see the value of storage heaters compared to other electrical forms of heating. Yes they use the cheaper rate of electricity, but they have high wattages, I think the highest wattage I have is 3kw. I'm on something called 'Superdeal' with Southern Electricity, which prevents me from switching supplier as no other company supports my meter. I don't know if it can be changed to economy 7 for free so that I can shop around or not.
Anyway to get back to my point. On this 3 tier system, I pay 16.09p per unit before VAT for my day rate. 7.52p for my night rate and 5.54p for stored heat. Now it sounds good when you look at it. 5.54p doesn't sound a lot at all. But being single and on a low income it does add up to quite a bit. I only run 4 out of 5 heaters at any one time, with the input setting on number 6 and the boost on number 1, the lowest setting. My electricity bill for the last quarter is £387.66 inc VAT.
As my stored heat is put seperately on the bill, I can see exactly how much of the bill applies to heating. My stored heating for the last 3 months was £241.63. so that's about £80 per month. Thankfully I prepay, not by meter, using internet banking. So I take meter readings fortnightly as I am paid, and pay as I go so to speak.
So my thought is, even if I were to use for example a 1kw quartz heater during the day, it would not cost me any more than the storage heaters.
The main disadvantage of storage heaters being if you have a sudden change in the weather, you either end up freezing waiting for the night rate to start, or stiffling hot because there's suddenly a warm day.
I'm certainly considering changing to radial heaters for that reason. That way I can just have the heating on when it's cold, opposed to having to keep an eye on the weather reports!
To the person who near the end, who mentioned switching to direct debit, I doubt there are any savings to be had, given the energy companies seem to over estimate what a person's energy needs are. I had a letter of complaint from Southern Electric because I wasn't sticking to my budget plan they had set out for me. I made it clear to them I was only prepared to pay for what I used, took fornightly meter readings and used a spreadsheet to calculate my usage and was never in arrears. I never heard anything from them after that. There are other considerations I save for in the summer, such as christmas, next years redecoration costs etc.
The only reason electricity is so expensive is because of the greed of energy suppliers, poor regulation and a weak government. Perhaps it's time we took a leaf out of the bolivians governments book and renationalized the energy companies, so that there is proper accountability.