Swap Electric Heaters for Modern Storage Heaters??

littleteapot

mmmmikey said:

On a different tack, don't forget to factor in the cost of any wiring changes needed to swap the panel heaters for night storage heaters. It's not just a question of timers for the E7 supply, there are also considerations around capacity. It's quite possible that existing wiring may be able to support 1 or 2 NSHs in place of the existing panel heaters but that isn't guaranteed and you may well work done on the house wiring and or the distribution panel/consumer unit/fuse box. It's really a question of what you're starting from and a job for a qualified electrician to check out. Keep in mind that when the NSHs heat up overnight there's a very high load on the electrical circuits all at once.

Good point. Although most modern NSHs have built-in timers so can run off a single constant-live feed, panel heaters tend to be fairly modest wattages (e.g. 1500w) so it was quite common wiring practice to put several of them on a single 32A ring.

Whereas because NSHs need, in the most extreme weather conditions, to effectively store 24 hours worth of heat in the space of only 7 hours charging time, they tend to be much higher wattage. For example the largest size of Dimplex, Creda, and Elnur NSHs can consume up to 3.4kW whilst charging. Therefore each one needs to be on a dedicated 16A radial circuit. Traditionally this is done via a second consumer unit which is fed from the contactor in a 5-port meter so only becomes live during the E7 period.

In addition to that, one needs to consider the total load on the incoming supply bearing in mind that all the NSHs plus potentially an immersion heater will start charging at almost exactly the same time. It was common pre-2000 properties for the DNO fuse to be only 60 Amps. 

Lets consider a typical 3 bedroom house of 70's - 90's construction with a medium level of insulation - approximate figures guessing heater sizes assuming a large lounge, two decent size bedrooms, one small bedroom and a decent size kitchen

1x 3kW immersion heater 13A
lounge 3.4kW NSH - 15A
kitchen 2.6kW NSH - 11A
bed 1 2.6kW NSH - 11A
bed 2 2.6kW NSH - 11A
bed 3 1.8kW HSH - 8A

Total current = 69A. That's busted the 60A DNO fuse rating before any other high power appliances are added e.g. a dishwasher being run during the E7 period. However it is usually possible to get the DNO fuse changed to 80A or 100A  and also the meter tails upgraded where necessary for a modest fee, assuming the incoming cable is actually of suitable gauge to support that current. 

QrizB

littleteapot said:

Lets consider a typical 3 bedroom house of 70's - 90's construction with a medium level of insulation - approximate figures guessing heater sizes assuming a large lounge, two decent size bedrooms, one small bedroom and a decent size kitchen

1x 3kW immersion heater 13A
lounge 3.4kW NSH - 15A
kitchen 2.6kW NSH - 11A
bed 1 2.6kW NSH - 11A
bed 2 2.6kW NSH - 11A
bed 3 1.8kW HSH - 8A

My opinionb, from having had stored heat in a 1970s 3-bed semi in the past, is NSHs are wasted in the bedroom; you're either in bed (and don't need them) or in another room (and don't need them). Keep the panel heaters for 30 mins of heat before bed and on waking if it's really cold.

That will save you 30 amps and £3k of installation cost.

[Deleted User]

littleteapot said:

Deleted_User said:

wittynamegoeshere said:

I think I'm right in saying that the difference between peak and off-peak prices is not as great as it once was.  I remember a jingly 1980s ad for heat electric that had a line saying "With half price electricity".  I doubt it's half-price these days.

Less than half the price compared to day rate is available in every region and almost every circumstance - and in most of those less than half the price of the single rate also.

EDF has been a bit of an anomaly over the past few years in terms of E7 pricing. Their night rate in most regions has consistently been  less than 50% of the day rate, and often much lower as seen in the deemed rate table above. Whereas with most other suppliers the night rate has been creeping up over the last 10 years as old nuclear and coal plants have been shut down, and is now as much as 80% of the day rate in some of the more extreme fixes I saw a few months ago.

Why is is that EDF is able to sell night rate electricity much cheaper than the other suppliers? Is there some anomaly whereby the retail division buys electricity directly from their generating division (mostly nuclear)? Although I dont think the market can actually work like that.

Fixed tariffs are not a good representation of the market, they're more a representation of a trading department's risk appetite.  Any other supplier could choose to offer exactly this day/night split - they just don't.  Actually, there's nothing stopping them offering 0.01p per kWh night rates and making the day rate stupidly high (as long as they hit the cap).

Spoonie_Turtle

QrizB said:

littleteapot said:

Lets consider a typical 3 bedroom house of 70's - 90's construction with a medium level of insulation - approximate figures guessing heater sizes assuming a large lounge, two decent size bedrooms, one small bedroom and a decent size kitchen

1x 3kW immersion heater 13A
lounge 3.4kW NSH - 15A
kitchen 2.6kW NSH - 11A
bed 1 2.6kW NSH - 11A
bed 2 2.6kW NSH - 11A
bed 3 1.8kW HSH - 8A

My opinionb, from having had stored heat in a 1970s 3-bed semi in the past, is NSHs are wasted in the bedroom; you're either in bed (and don't need them) or in another room (and don't need them). Keep the panel heaters for 30 mins of heat before bed and on waking if it's really cold.

That will save you 30 amps and £3k of installation cost.

Depends on the number of occupants, their habits (e.g. children/teenagers spending time in their rooms), and their health to a degree (still need to heat the bedroom in winter if you have to be in bed for much of the day).

EssexHebridean

littleteapot said:

Deleted_User said:

wittynamegoeshere said:

I think I'm right in saying that the difference between peak and off-peak prices is not as great as it once was.  I remember a jingly 1980s ad for heat electric that had a line saying "With half price electricity".  I doubt it's half-price these days.

Less than half the price compared to day rate is available in every region and almost every circumstance - and in most of those less than half the price of the single rate also.

EDF has been a bit of an anomaly over the past few years in terms of E7 pricing. Their night rate in most regions has consistently been  less than 50% of the day rate, and often much lower as seen in the deemed rate table above. Whereas with most other suppliers the night rate has been creeping up over the last 10 years as old nuclear and coal plants have been shut down, and is now as much as 80% of the day rate in some of the more extreme fixes I saw a few months ago.

Why is is that EDF is able to sell night rate electricity much cheaper than the other suppliers? Is there some anomaly whereby the retail division buys electricity directly from their generating division (mostly nuclear)? Although I dont think the market can actually work like that.

Not a massive difference between EDF and Octopus in the Eastern region - Octopus are 3p more on the night rate, but you do seem to get the advantage of getting far better some actual customer service which we decided was worth the extra £70 a year or so it was going to cost us. 

Swipe

I plan on going to bed earlier this winter and waking early instead to make the most of the warmer times of my house

StuffTheCap

QrizB said:

littleteapot said:

Lets consider a typical 3 bedroom house of 70's - 90's construction with a medium level of insulation - approximate figures guessing heater sizes assuming a large lounge, two decent size bedrooms, one small bedroom and a decent size kitchen

1x 3kW immersion heater 13A
lounge 3.4kW NSH - 15A
kitchen 2.6kW NSH - 11A
bed 1 2.6kW NSH - 11A
bed 2 2.6kW NSH - 11A
bed 3 1.8kW HSH - 8A

My opinionb, from having had stored heat in a 1970s 3-bed semi in the past, is NSHs are wasted in the bedroom; you're either in bed (and don't need them) or in another room (and don't need them). Keep the panel heaters for 30 mins of heat before bed and on waking if it's really cold.

That will save you 30 amps and £3k of installation cost.

That's what I was also thinking. Having the NSH for mainly the winter means I'll be paying a higher day rate for the whole year instead 

mnbvcxz

You do hear a lot of nice things about dimplex quantum hhr storage heaters. If you have no choice, such as an all electric flat, then they are probably the best of the poor options available. Not at all cheap though, particularly if you need several.

That said you are officially meant to have two electricity cables to each one which can add to the cost. One to keep the computer always going and one to charge up the heating.

They are meant to intelligently monitor the weather conditions and predict the right amount of electricity to store for the next day so you have not too much or too little. I find this a little disconcerting, I sort of prefer to be in control of the settings not fighting with an algorithm. Though it clearly works for many people.

Economy 7 does not seem likely to be the future. The future appears to be prices fluctuating randomly throughout the day depending on when the wind is blowing and such. Your devices will then need to activate themselves at the cheap moments. Its not clear how well current Dimplex Quantums will be able to be adapted to this future. They are rather hardwired to the idea of economy 7 fixed overnight periods. Some people have got around this but it did not sound fun or easy. I do wonder if in three years or so there will be a new generation of intelligent quantum storage heaters that integrate better with your smart meter. Will the current ones then be up gradable or white elephants? Who knows.

Some people manage to use mini split ac heat pumps instead. But not possible or affordable for everyone.

So personally I'm going to limp on with my old credas and hope the future becomes clearer in a year or two.