Economy 7 and electric heater

Jemima154

Hi all, long time lurker, first time poster. 

I have an old flat with plug in electric heaters, they cost a fortune to run during the day (about 27p an hour)

my question is - if there a storage battery that I could plug in and charge overnight when my electric is cheaper and then plug it in when I finish work and use the heater that way? 

Has anyone any suggestions on which to buy? 

Jem 

MforumSManE

Probably not, if I look at my UPS (Uninterruptable Power Supply) used to keep my Broadband and PC working during power cuts it cost £400 and will only keep a full load of 2.4Kw running for 10-30mins.

Your best option with an E7 tarrif is to get modern storage heaters that charge over night (Providing your wiring is up to the job). A friend of mine has a modern Dimplex Storage heater in his kitchen that is super slim and pumps out good heat during the day.

Scot_39

Have you considered simply asking to be billed at single rate for both registers - peak and off peak instead ?

Many who fall below the 30+ to 40+ percentage for off peak use vs total for breakeven for SR annually have.

Dk you know your current off peak register to total kWh use ratio ?

Battery and invertor kit ranges massively - some are fixed capacity - some are stackable in terms of storage with one invertor module plus n batteries etc.  Price will depend on how many kWh per day would you want to shift - and how much power youd want to draw continuously ?

1 say 2-3kW fire, 2, 3 etc

TheElectricCow

While such a thing does exist, in practical terms the initial cost of the necessary equipment would almost certainly outweigh the savings you’d get charging on a standard E7 tariff over the effective life of a plug in battery system.

For space heating over any meaningful amount of time you’d need a system with quite significant capacity, which is likely to cost far more than installing a set of Storage Heaters designed to work with Economy 7.

Storage Heaters work on the same principle of your battery idea where they “charge” overnight on cheap rates and release that energy during the day. The main advantage of these is the energy is stored as directly as heat rather than electricity, and in simple terms it’s much easier (and therefore cheaper) to store enough heat to keep a home warm in the bricks of a storage heater than it is to store an equivalent amount of energy in an electric battery to use as heat later. They also will not wear out over time in the same way a battery under constant heavy use would.

If storage heaters aren’t for you then it may be worth investigating if changing away from Economy 7 is worthwhile for you - This can be done free of charge by your energy supplier, where the most common method is they simply charge both day and night rates at the same amount.

Gerry1

A battery is unrealistic, the cost would be humongous.  If there's any possibility of getting gas then that's the way to go, assuming you own the flat.

Otherwise it's High Heat Retention Night Storage Heaters such as Dimplex Quantum.  As they'll need new wiring, make sure each has two supplies, one 24h and one E7.  They can work with just a 24h circuit but it's not worth the risk of a high bill if you get the timing wrong.

In the meantime, switch to single rate.  You won't need a new meter.  If the supplier won't play ball, just ditch and switch.

Gerry1

Some more thoughts.

• Unlike single rate, E7 tariffs aren't all much the same, they vary significantly: the lower the night rate, the higher the day rate.  You'll have to make a guess and review it after you have a year's meter readings.

• Best to run the immersion heater on a 24h circuit with a local timer (Horstmann or similar) that has a Boost facility to use day rate electricity for an hour or two.  You don't want to return from holiday and find there's no way to get hot water until the following morning !

• Make sure one E7 outlet has a neon indicator so that you can see at a glance when it's lower rate.  You can then be certain when it's cheaper to use the tumble dryer, immersion heater etc.  Beware that some areas have a 2-hr peak rate interlude after midnight.

Jemima154

Thank you all this was really helpful  

dealyboy

... hope you post again Jemima