More flexible electric heaters

Typhoon2000

If you would rather just use the heaters you have ( or new electric heaters) more efficiently so you switch on the the rooms when you want, you can use one of the many smart heating solutions.
here is one that will work with electric heaters.
https://shop.lightwaverf.com/pages/lightwave-smart-series-heating?srsltid=AfmBOop3H9EtRzOnDFQgKdnMofMoNss0cOpgL4G0aeumDYbn_Xj_dOOn

GDB2222

MalthouseMark said:

@Gerry1 yes, I am aware that whoever put them in fifteen years ago wasn’t “cooking on gas” (I hate to think how old that advert is now).

I did look at @QrizB link in his footer to see what difference E7 might make but couldn’t make head or tail of it. ChatGPT couldn’t give me a good percentage of saving for E7 compared to non-E7. Best it could do after a long chat was suggest savings between 7 and 30%. Let’s be optimistic and use the 30% figure.

We are currently with Utility Warehouse Double Gold tariff and manage to run our home on about 10,000 kWh a year (rolling 12 month average) and £200 per month (again rolling 12 month average) which covers (obviously) all heating and cooking, computers, lighting etc. January is usually the worst month and last month’s bill for December was 1206 kWh at £282 or £299 including standing charge. (UW put our 12 month usage as 9183 kWh),

Assuming £1000 per room to convert (ignoring all the sockets which have been switched in the home and cost of converting the wiring), we have, downstairs, bathroom, two bedrooms, one home office, and a hall heater, upstairs a hall heater and a large odd split-level room with three heaters in it. I’ll call that seven rooms for ease. Call it £7k to convert.

Electricity bills at £200x12 = £2,400.

Assuming that we could save as much as 30% on our usage pattern and bringing £2,400x0.7=£1,680 saving £2,400-£1680=£720 per year.

£7,000/£720=9.722 years to recoup the outlay. Certainly power prices will only go up so it may be less, and if heating is our main component of our bill then savings could be higher and payback time sooner.

That’s a heck of a long payback time.

Which is why I have to look at it in terms of comfort and convenience first and foremost. At our age a long payback time isn’t something to ponder too hard. Real cost savings are all very well… once any changes have paid for themselves.

We took the same approach for getting the place double glazed and used some of a pension lump sum to have more comfort - not to save money. Well worth it!

Updating a few key rooms for comfort (our bedroom, my office, and our lounge) and then, if we can afford it later, changing the hall, spare room, and bathroom, is more likely.

Are your sums right, though?

Night rate electricity is a third of the price of standard rate, so by moving to storage heaters, you should save two thirds of the part of your electricity bill that relates to heating. Your 30% figure is only right if roughly half your electricity is used for things other than heating. Do you think that is correct?

The other thing is that you are talking about ripping out your current heating and replacing it with something similar but with different controls. That’s going to cost several hundred per room, surely? So, considering storage heaters instead, it’s only the extra cost of those that you need to set against the electricity cost saving.

The only E7 installation I have practical experience with dates from the 1970s. It has a separate circuit for items meant to run on night time electricity. I don’t know if that is the same these days? It’s simpler to use the normal circuit, and control the night rate appliances with electronics. Is that how it works now with new installations? 

Typhoon2000

Economy 7 historically had two circuit. Everything plugged in to the 1st circuit will be normal rate during the day and cheaper during the E7 hours. The second circuit only switches on during the E7 hours allowing you to use storage heaters without having to use a programmer to switch them on at the appropriate time. You have never needed to use the second timed circuit to benefit from E7, you could plug your heater into the main circuit and use a timer.

MalthouseMark

GDB2222 said:
Are your sums right, though?

Night rate electricity is a third of the price of standard rate, so by moving to storage heaters, you should save two thirds of the part of your electricity bill that relates to heating. Your 30% figure is only right if roughly half your electricity is used for things other than heating. Do you think that is correct?

Who knows?! Maths never was my strong point. Hence showing my workings!

If I look at the UW Tariff Labels then I'm in Southern area. Unit rate for Electricity = 23.789 pence/kWh.
On their Economy 7 rate that would be 34.875 pence day time and 6.008 pence night time.

As I had to look at that I just downloaded the latest bill too. It tells me that I used 1471 kWh in January (always our biggest month) and it cost us £349.94 plus £16.95 standing charge to give a bill of £366.89 for our electricity.

Putting that into my spreadsheet going back to 2013 (at our old home) I can see that the average at this home only is £2,236 per year. and our rolling average over a 12 month period is currently just £200.90 per month and 9,167kWh.

If I take those raw figures I see as follows (the advantage of doing this on my PC with Excel in front of me rather than doing it sat in bed using an iPad):

9,167 kWh x 23.789 p/kwh = £2180.74 per year at "double gold" prices. The standing charge is about £200 with either option for the year.

Asking Google/Gemini or ChatGPT what proportion of my household energy is likely to be heating in an all electric house gives answers from 30-60%... let's be generous and use 60% is heating and the rest is stuff like cooking, washing, dishwashing, vent fans, dehumidifiers and the like... 60% goes on my heaters. For the sake of argument. @QR@QrizB used an 80/20 split for heat and everything else but that feels a little high to me.

If I put in an 80/20 split
7333.6 kWh at 6.008p = £400.60 for heating
1833.4 kWh at 34.875p = £639.40 for everything else
That's £1080.001 total and would save £1100.74 a year.

However if I go for more of a 60% on heating so 60/40 split
5500.20 kWh at 6.008p = £330.452 for heating
3666.80 kWh at 34.875 = £1278.797 for everything else
That's £1609.25 total and would save only £571.49 a year.

So whilst the headline "it saves loads" looks great that is only if most of the power goes on heating.

At an 80/20 split £7000 would take me a shade over 6 years to pay off.
At a 60/40 split £7000 would take me a shade over 12 years to pay off.

One option we have is to change the control panels on the Rointe units to get newer ones. That would cost much less and give us convenience without the E7 issues.

A saving is all very well if I can recoup the outlay that it takes to get it.

MalthouseMark

Typhoon2000 said:

Economy 7 historically had two circuit. Everything plugged in to the 1st circuit will be normal rate during the day and cheaper during the E7 hours. The second circuit only switches on during the E7 hours allowing you to use storage heaters without having to use a programmer to switch them on at the appropriate time. You have never needed to use the second timed circuit to benefit from E7, you could plug your heater into the main circuit and use a timer.

That's what I seem to remember - two circuits. The Rointe heaters (i.e. "non storage heaters") were fitted into the E7 circuit years ago, before we came, as it is a higher rated circuit capable of running heaters. But they were not running at night so it was costing lots.

The supplier moved us to a single rate and put both circuits into the one supply box to save money (i.e. not doing things at "day rate" instead moving to a comparatively lower "one rate all day or night") However the radiators are fixed in position and plugged into that old E7 night-time circuit. Oh and several of those were single sockets in the past but were swapped to double sockets to so we now use them for other things. In other words if we went to E7 again all the "non storage heaters" would be plugged in to the wrong circuit (which, whilst it is a circuit rated for the higher load of a bunch of heaters, is intended to be used at night) and things plugged in to the double sockets would not work unless it was the E7 night period and that circuit were activated.

Or that's how I see it. I could be completely wrong as what the electricians actually did is not stuff I understand properly. However there's more than enough potential for it to be an utter mess with things we rely on not powered on.

As a simple example the PC that I'm typing this on is plugged into a double socket. The other plug has a radiator fixed to the wall by the desk... that would therefore be an E7 circuit. It would end up only being "on" during the night and therefore would the PC work?! I really don't know!!! I would have expected power to be able to allow a genuine storage heater to work during the day (i.e. run its program).

The whole thing confuses the heck out of me. Which is another reason I'm skeptical about any switch back to E7.

GDB2222

MalthouseMark said:

Typhoon2000 said:

Economy 7 historically had two circuit. Everything plugged in to the 1st circuit will be normal rate during the day and cheaper during the E7 hours. The second circuit only switches on during the E7 hours allowing you to use storage heaters without having to use a programmer to switch them on at the appropriate time. You have never needed to use the second timed circuit to benefit from E7, you could plug your heater into the main circuit and use a timer.

That's what I seem to remember - two circuits. The Rointe heaters (i.e. "non storage heaters") were fitted into the E7 circuit years ago, before we came, as it is a higher rated circuit capable of running heaters. But they were not running at night so it was costing lots.

The supplier moved us to a single rate and put both circuits into the one supply box to save money (i.e. not doing things at "day rate" instead moving to a comparatively lower "one rate all day or night") However the radiators are fixed in position and plugged into that old E7 night-time circuit. Oh and several of those were single sockets in the past but were swapped to double sockets to so we now use them for other things. In other words if we went to E7 again all the "non storage heaters" would be plugged in to the wrong circuit (which, whilst it is a circuit rated for the higher load of a bunch of heaters, is intended to be used at night) and things plugged in to the double sockets would not work unless it was the E7 night period and that circuit were activated.

Or that's how I see it. I could be completely wrong as what the electricians actually did is not stuff I understand properly. However there's more than enough potential for it to be an utter mess with things we rely on not powered on.

As a simple example the PC that I'm typing this on is plugged into a double socket. The other plug has a radiator fixed to the wall by the desk... that would therefore be an E7 circuit. It would end up only being "on" during the night and therefore would the PC work?! I really don't know!!! I would have expected power to be able to allow a genuine storage heater to work during the day (i.e. run its program).

The whole thing confuses the heck out of me. Which is another reason I'm skeptical about any switch back to E7.

Modern night storage heaters don’t need a separate circuit, so you are okay. The electricity to them stays on 24/7, but they only switch themselves on during the cheap times. So, you don’t need to alter your wiring, as you just wire the storage heaters in place of your existing heaters. 

At least, that’s how I understand it, but it would be great for an expert to confirm. 

twopenny

Can't confirm but I know a lady who had the new storage heaters (because there was only electric to the bungalow) and she said they were amazing compared to the old sort.

She loved them.

Sadly, I don't think she's around now or I'd ask what sort she had.

MalthouseMark

MalthouseMark said:

9,167 kWh x 23.789 p/kwh = £2180.74 per year at "double gold" prices. The standing charge is about £200 with either option for the year.

Asking Google/Gemini or ChatGPT what proportion of my household energy is likely to be heating in an all electric house gives answers from 30-60%... let's be generous and use 60% is heating and the rest is stuff like cooking, washing, dishwashing, vent fans, dehumidifiers and the like... 60% goes on my heaters. For the sake of argument. @QR@QrizB used an 80/20 split for heat and everything else but that feels a little high to me.

If I put in an 80/20 split
7333.6 kWh at 6.008p = £400.60 for heating
1833.4 kWh at 34.875p = £639.40 for everything else
That's £1080.001 total and would save £1100.74 a year.

However if I go for more of a 60% on heating so 60/40 split
5500.20 kWh at 6.008p = £330.452 for heating
3666.80 kWh at 34.875 = £1278.797 for everything else
That's £1609.25 total and would save only £571.49 a year.

So whilst the headline "it saves loads" looks great that is only if most of the power goes on heating.

At an 80/20 split £7000 would take me a shade over 6 years to pay off.
At a 60/40 split £7000 would take me a shade over 12 years to pay off.

One option we have is to change the control panels on the Rointe units to get newer ones. That would cost much less and give us convenience without the E7 issues.

A saving is all very well if I can recoup the outlay that it takes to get it.

My wife suggested looking at the Summer, when our heating isn't on, and saying, "that's what we spend without heating" in a typical month. As it happens my spreadhseet has a worksheet which looks back 24 months on a month-by-month basis.

We average 847.61 kWh per month. Over July/August/September the average becomes 369 kWh which is 44% of the energy of an average month of a full year is "not heating" but other stuff.

Going back to the figures then, for our home, a 56/44 split would be more sensible. If we went E7 we'd see this:

9,167 kWh x 0.56 = 5176.228 kWh at 6.008p/kWh = £310.99 on heating per year
9,167 kWh x0.44 = 3,990.770 kWh at 34.875p/kWh = £1,391.78 for everything else
That's a £1702.77 total on E7 which would save £477.99 per year compared to current £2,180.74 per year.

£7,000 investment would therefore take 14.65 years to recoup. 

QrizB

The "average" dual-fuel property (with gas for heating) only uses 2700kwh of electricity a year for everything, which makes me think your estimate of almost 4000 is on the high side.

Some of your summer usage is hot water, which you'd also move to E7. I'm not going to guess how much of your summertime electricity is used for water, but we've got a 140 litre tank and heating it daily from cold with electricity would take about 8kWh a day, 240 a month.

MalthouseMark

QrizB said:

The "average" dual-fuel property (with gas for heating) only uses 2700kwh of electricity a year for everything, which makes me think your estimate of almost 4000 is on the high side.

A bit like the energy cap reports only talk about dual-fuel scenarios. I struggle to find details for electric only homes. But include my baking habit, and my wife’s baking habit and it may not be that far off. Certainly not near an 80/20 split.