Economy 7 or not Economy 7

psychoceramicist

I'm currently on British Gas dual fuel and am considering asking for an Economy 7 meter. I've enquired with BG and they tell me it will cost £35 for the switch. A bit disappointing. However, they also say that I need to have my storage heater(s) installed BEFORE they will change my meter so that they "can test the installation". This sounds strange. It implies that I need my heaters (and whatever else I want to take advantage of the cheap rate) somehow connected to a separate circuit. I assumed that it worked by simply having a meter that used a timer to clock my offpeak usage separately from my "onpeak" usage. So if I chose to do my laundry at 3am that would be charged at offpeak rates as well, and they could use my wahing machine to "test the installation". Needless to say, asking anybody at the call centre for an explanation is a waste of time - "that's the rules". I've heard that Britsih Gas don't like Economy 7 much - are they simply trying to put me off or is there more to it than simply upgrading the meter?

Fire_Fox

If you are on dual fuel, you presumably have gas central heating and a gas bioler for hot water? If so why do you want Economy 7?? Your energy hungry processes are heating, hot water and tumble dryers. If you don't have two of these on electric you are automatically paying less, as gas is cheaper per KWH. By switching your day rate will be more than you are paying per unit at present, and so your TV, lighting etc. will all be more expensive.

psychoceramicist

Good point but I'm assuming that offpeak electricity will be cheaper, even than gas, to provide heating during the day. I'm working from home now so the well known disadvantage of storage heating being warm while I'm out during the day and cold when I'm back in the evening doesn't apply in the same way. That may be a hasty assumption though!! What do you think?

Fire_Fox

psychoceramicist wrote: »

Good point but I'm assuming that offpeak electricity will be cheaper, even than gas, to provide heating during the day. I'm working from home now so the well known disadvantage of storage heating being warm while I'm out during the day and cold when I'm back in the evening doesn't apply in the same way. That may be a hasty assumption though!! What do you think?

You want to pay out to have storage heaters fitted, and a new meter so you can use night rate electricity for a couple of months a year?? You really need to do your homework first. Read my thread about comparing usage figures of two flats on economy 7, with and without storage heaters.
http://forums.moneysavingexpert.com/showthread.html?t=1397217

IMO you would be better off using the system you have sensibly. Ensure your property is well insulated, set your thermostat to 18-20C and wear an extra layer around the house.

psychoceramicist

No I don't "want" to pay out for anything, I'm exploring the options ie "doing my homework".
I'm talking about one storage heater which, in my part of Yorkshire anyway, will be used about 8 months a year.
And if I want advice about being sensible and wearing an extra layer, I'll ask my granny thanks.

paceinternet

psycho, the problem is that E7 tariffs charge you more than normal tariffs for the kwh you use out of the E7 period, in particular the standing charge equivalent first x kwh per year. So even though the storage heater might cost you about a £1 a night to run on E7, you need to work out what the additional costs will be for your other kwh. Then consider what the real cost of running the storage heater is.

A lower running cost solution could be an air source heat pump for the room you are working in if it is cosmetically acceptable, and stay on a normal daytime tariff. You will get roughly 3 kw of heat for 1 kw of electricity at around 10 p per hour, so 8 hours will cost you 80p with no E7 penalty.

However, if you can add controls to your gas ch system to only heat the one room effectively, that should also be considered and will have a lower running cost than the E7 storage heater.

psychoceramicist

Thanks for the input Pace. BG only charge about 10% more for non-E7 rates so, as I would be spending most of the working day in my E7 heated room, it is not too worrying. Especially if I can run things like washing machines during the E7 period. That brings me back to my original question about why BG would want my storage heater(s) installed before they will change my meter, if I can run other appliances on the E7 tariff.

To get the c.h. working upstairs (where the room will be) might be the way to go - we don't use it at the moment - but I'm just comparing costs.

How do these air source heat pump thingys work? At 3kw out for every 1kw in, it sounds like another challenge to the laws of Physics. Is it some kind of heat exchanger?

Fire_Fox

psychoceramicist wrote: »

No I don't "want" to pay out for anything, I'm exploring the options ie "doing my homework".
I'm talking about one storage heater which, in my part of Yorkshire anyway, will be used about 8 months a year.
And if I want advice about being sensible and wearing an extra layer, I'll ask my granny thanks.

Clearly I have p***ssed you off: I apologise for any offence. You specifically asked what I think, and I believe I am in a good position to warn you off E7. Both my parents and I live in Yorkshire and we run as many appliances overnight as we can. We are all at our respective homes a fair bit of the day, as you are. Your original query was on a money saving website so suggesting insulation and wrapping up better is not unreasonable - once you have read around a bit you will see how many posters don't think of this!

paceinternet

Some E7 systems have a relay that switches a circuit on only for the E7 period. You have to cable your storage heaters to this circuit, but then they do not get a supply out of the E7 period. Maybe that is what BG have in mind. Otherwise, you need timers on each appliance to make use of E7. You need to ask BG what they are providing.

ASHP's, as they can be called, are available in various forms, but for one room you would be looking at an air to air system. It is an airconditioning unit similar to those in offices and shops with a fan unit in the room and an external fan driven heat exchanger. The external unit has a compressor inside it and operates similar to a refridgerator,. So when heat is required it draws in external air and expels it at a lower temperature. The refidgerant heats up and is piped to the internal unit. Like a refridgerator in reverse.
It can be used to cool the room as conventional air conditioning unit whereby the external unit draws air in and heats it up before expelling it. It heats it up by extracting heat from the refridgerant which is then chilling the air inside the room.
Lots of posts in the Fuel and other heating forum if you do a a search

psychoceramicist

No offence taken . You're obviously not impressed by E7 but it must have its place - I'm trying to find out if it's my place. One factor is whether the tariff applies to all appliances used during the offpeak hours. This was how I assumed it worked but BG's attitude suggested not (see original post). That's what I was hoping to get answers on.

paceinternet

Well on your last point, the whole supply to the property during the E7 hours would be recorded on one meter, and the other meter would record everything consumed outside of the E7 period.

It is after the meters that some properties have a separate circuit that is ONLY energised during the E7 period. All other circuits are also energised during the E7 period.
The E7 circuit (maybe 80 amps) is normally for a whole house of storage heaters to avoid having to timer every one. Some cost involved in this on your part. So for one strorage heater, you would keep your existing distribution system and have an individual timer on the one storage heater.