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Cost to charge by energy provider - round 3!

DaveW

Active Member
May 21, 2019
1,188
950
Beds, UK
Bit worried with the other sheet it might have got people considering switching over purely for the cheapest overnight rate, which with some of them means a much higher day rate.

Google suggests that the average UK household uses between 8-10 kWh per day, so I've opted for 9 kWh per day. This will obviously vary based on how big your house is, or how much energy you generally use. The calc also includes the standing charge for the day on the household and household + charging figures.

Hopefully this is helpful, if you've got more suppliers that are worth adding (I've had a good look round, most of them aren't that EV friendly to be honest!) then please let me know. Similarly, if you've any feedback on this, let me know.

Sadly can't include Agile as I just wouldn't be able to keep up with it :D

Tesla - Cost to home charge by provider v3
 

MikeHolliday

Member
May 9, 2020
378
275
Worthington, Ohio
Wow, I wish I could operate my house on 9kWh per day. My low month for the year is 700 kWh and my high month is 1,200 kWh. Which means that I am averaging between 23.3 and 40 kWh per day and I have a fairly modest home with all LED lighting. How does someone in United Kingdom use so little power?
 
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Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
2,782
2,912
UK
The biggest factor for us is time of use, we use about 56% of our total usage between 00:00 and 07:00 each day over the course of the whole year, with that ratio increasing to about 70% overnight during the heating season (which has just started, our heating came on last night for the first time this year).

Not sure how to best incorporate that into any generic cost comparison spreadsheet, though. The spreadsheet I use has several years worth of usage data, as measured and logged every 6 minutes (so 10 readings per hour), but I'd guess that few people would have such a dataset to work with. For us, neither Go nor Agile yet give the best deal, but Agile is getting pretty close. The main reason Agile seems to be edging closer is that the overnight period, when we use most electricity, is cheaper than E7, but that's offset a bit by the tendency for the rate to be fairly high in the late afternoon, and at this time of the year our PV system barely generates anything after about 15:00, so cannot offset the higher imported cost.
 
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MikeHolliday

Member
May 9, 2020
378
275
Worthington, Ohio
Ok, here is a stupid question. Is the electricity in the UK so expensive that people are very careful to ration it? Where I live in the US we pay about $0.10/US Dollars per KWh regardless of the time of day in which I use it. What is the typical cost of a KWh of electricity in the UK?
 

Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
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UK
Wow, I wish I could operate my house on 9kWh per day. My low month for the year is 700 kWh and my high month is 1,200 kWh. Which means that I am averaging between 23.3 and 40 kWh per day and I have a fairly modest home with all LED lighting. How does someone in United Kingdom use so little power?

We have an all-electric home, no oil or gas, just electricity for heating, hot water, light and charging the car. Our average usage is about 3,000 kWh per year. If I subtract the grid electricity used to charge the car, then the house itself only uses about 2,000 kWh/year, or about 167 kWh/month, significantly better than most UK houses, but then it is well-insulated and has a large PV array in the roof. I doubt that many houses here that use electricity for heating and hot water get close to our level of electricity consumption, TBH, we're very much an outlier. We generate far more electricity in a year than we use, typically our annual generation will be around 6,000 kWh (this year it's closer to 6,500 kWh). That generation offsets our daytime energy use, especially in summer, where it's usually enough to run the aircon, with a fair bit left over to charge the car.


EDITED to fix a typo
 
Last edited:

Adopado

Active Member
Aug 19, 2019
4,536
3,422
Scotland
Average is about 19 cents per kWh.

But cheap rate night time 4 hour charging for as little as $0.065 per kWh depending on supplier. In addition to our kWh charges we also pay a small additional daily charge whether you use any electricity or not.
 

Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
2,782
2,912
UK
I am surprised that your homes are all electric. I have friends in Ireland and they heat with oil.

Most homes in our village use oil for heating, but our winter heating requirement is lower than our summer cooling requirement, so we use two heat pumps, that can be used to both heat and cool. In practice, whenever we need cooling we'll be generating more than enough electricity from the PV system to run the heat pumps, so cooling is free. When we need heating, that only runs at night, warming up the insulated concrete ground floor, that then stores the heat and releases it through the day. This means we can heat the house mainly with cheaper off-peak electricity.

Our house isn't very typical for the UK, though. We have 300mm of insulation under the floor, 300mm of insulation in the walls and 400mm of insulation in the roof, which is a fair bit more than average for the UK.
 

MikeHolliday

Member
May 9, 2020
378
275
Worthington, Ohio
Your are telling me that you have 12 inches of insulation in your floor and walls, WOW. I live in Ohio and have only 3.5" of Fiberglass R-15 insulation and we have winter days that time get to 15 degrees below 0 Farenheit. Even our most insulated home in the US do not have 12 in. in the walls. That is amazing. If a house like that is built tight you could almost heat it with a stupid candle.
 

VanillaAir_UK

Well-Known Member
Jun 17, 2019
8,745
6,311
Surrey, UK
Moderator comment - Can we keep to units and pricing relevant to the UK and Ireland part of the forum please. Thats £/€ and degrees C. Whilst it may seem polite to convert to visitors units, this ensures that any visitors to this sub forum can convert to/from units relevant to their own circumstances if required. Quoting both units where relevant covers all bases.
 

Lupe

Member
Dec 31, 2019
186
83
UK
Wow, I wish I could operate my house on 9kWh per day. My low month for the year is 700 kWh and my high month is 1,200 kWh. Which means that I am averaging between 23.3 and 40 kWh per day and I have a fairly modest home with all LED lighting. How does someone in United Kingdom use so little power?

We are the same
 

Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
2,782
2,912
UK
Your are telling me that you have 12 inches of insulation in your floor and walls, WOW. I live in Ohio and have only 3.5" of Fiberglass R-15 insulation and we have winter days that time get to 15 degrees below 0 Farenheit. Even our most insulated home in the US do not have 12 in. in the walls. That is amazing. If a house like that is built tight you could almost heat it with a stupid candle.

You're right. Most of the time there's enough waste heat from electrical stuff in the house, plus two of us giving off around 80 W each, to keep the place warm. Our heating came on for the first time this winter the night before last, when the outdoor temperature dipped down to about -2°C for a couple of hours or so. It didn't come on again last night, as there's enough stored heat in the slab. Our absolute worst case heating requirement is about 1.6 kW, when it gets down to -10°C outside. Because of the heat pump, and it's COP of about 3, that equates to an electrical power of about 530 W to keep the house at 22°C when it's -10°C outside. The temperature here rarely drops that low, I think the lowest we've ever seen is about -6°C, and even then that was just for a short time, less than a day. Most of the time, the winter outdoor temperature is around 5 or 6 °C, so not really cold by North American standards.
 

phil4

Member
Sep 8, 2020
352
202
UK
DaveW, can you add in a "how many KWh you use each day" cell so people can change it from the default 9?
 

DaveW

Active Member
May 21, 2019
1,188
950
Beds, UK
DaveW, can you add in a "how many KWh you use each day" cell so people can change it from the default 9?

I can make an 'advanced' version (previously got complaints about it being too much to enter / too much data), would it be better off with a single kWh figure (so assuming like in the original calc, it's kWh in the day rate, or day and night? (wondering who (other than @Glan gluaisne) might know that data

E.g.

Screenshot 2020-11-05 at 13.35.01.png
 

phil4

Member
Sep 8, 2020
352
202
UK
I think the way you've done it there is perfect.

And yes, I know, I was one of those people saying having too many figures and too much going on doesn't help, but I think your flow across the top works nicely on this, and it doesn't go too far.

Tough crowd. Sorry.
 

DaveW

Active Member
May 21, 2019
1,188
950
Beds, UK
I think the way you've done it there is perfect.

And yes, I know, I was one of those people saying having too many figures and too much going on doesn't help, but I think your flow across the top works nicely on this, and it doesn't go too far.

Tough crowd. Sorry.

Didn't recognise the avatar change :)

How does this one work for you: Tesla - Cost to home charge by provider v3 - Advanced
 
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Bernard_S

Member
Jun 21, 2019
314
149
Kettering UK
I am surprised that your homes are all electric. I have friends in Ireland and they heat with oil.

In the UK about 95% of house heating uses gas. Cost to run is about 1/3rd the cost of electric heating, unless you have a heat pump. Most of our housing stock is poorly insulated compared to what it ought to be.
 

Glan gluaisne

Supporting Member
Supporting Member
Sep 11, 2019
2,782
2,912
UK
95% is a bit high, as a fair bit of the country is off the gas grid (unsurprisingly, we are, as are all the villages around here). The current figures for home heating are about 85% gas, 6% oil, 6% electricity, 3% solid fuel. Gas is planned to be phased out eventually. At some point in the next ten years there is likely to be a ban on fitting gas heating to new homes (was planned to come into force in 2025, but I believe this has been put on hold for now).
 

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