Air Source Heat Pump - how much should I expect to pay on energy bills?

Damob123

Hello,

I'm looking for a comparison from other people in a similar situation to us.

We live in a 3 bedroom semi-detached property that I'd consider to be well-insulated (give or take the odd small draft). I've had a Mitsubishi Air Source Heat Pump installed, along with wet underfloor heating and radiators. Our whole property runs off electricity - heating, kettle, oven, the lot, as we're off grid. It's also worth mentioning that I live here with my partner and an 18-month-old baby. 

I'm on economy 7, and my provider is EDF, and they've told me that my expected annual energy usage is as follows:

Daytime: 5000 KW
Night: 1,500 KW
Total: 6,500 KW per annum 

This is costing us in the region £205 per month. Even with an Air Source Heat Pump installed, which I was led to believe would cost us around a third of the normal person's energy bill. Whilst I understand that energy bills have skyrocketed lately, I'm struggling to comprehend that our usage is correct. I also work from home, so I'm willing to accept that costs may be a little higher than normal. 

What are other people paying? What's your experience?

QrizB

Welcome to the forum.

Ofgerm's average home gets through almost 15000kWh of energy a year, 12000 of gas (heating and HW) plus 2900 electricity. If you're only using 6500kWh you're doing well and it sounds as though your heat pump is doing its job.

From the day/night split, you would probably be better off on a single-rate electricity tariff rather than E7.

At the current capped tariff, a 6500kWh/yr consumer should be paying around £1500/yr. That's £125/month, not £205. A few questions for you:

• How long have you had the heat pump?
• Do you have any arrears?
• Is EDf's estimate consistent with your own meter readings?
• Can you give details of your tariff please?

Verdigris

How hot do you have the house? How much insulation is in the walls and roof?

Your estimate for kWh (not KW) used per annum looks relatively low. How much are you paying, per kWh, on each rate? Your monthly payment implies about 38p/kWh, which is incredibly high, even in these times.

tim_p

EDF figure is an estimate, what actual usage are you seeing?  So meter readings from pre ASHP and those subsequently. Presumably you have relevant meter readings?

Reed_Richards

I have a 12 kW  ASHP in a 4 bedroom bungalow, all radiators.  Last year it alone used just short of 7000 kWh.  This should be about a third the running cost of another sort of electrical heating but amounts to a similar running cost to the oil boiler I had before. 

matelodave

A heatpump run at its optimum will deliver around 3kwh of heat for every 1 kwh of leccy, but as leccy is expensive so is the cost
of a kwh of heat - around 7p/kw in my case.

Although heatpumps may use less energy and can be more efficient than other forms of heating, they aren't cheaper to run. The cost of 1kwh of heat is more than mains gas, oil or possibly even LPG, but they are cheaper than other forms of electrical heating.

I also have a heatpump and an all electric bungalow and get through between 7000-8000kwh a year of which about 50% is for the heatpump and 50% for everything else.

For us (and I'd suspect for you as well) there's no advantage in being on an E7 tariff..There is no point in having cheaper night time leccy and paying more during the day if you cant take advantage of the cheaper rate.  I'm on a single rate tariff because the heatpump does most of its heating and we use most of our leccy during the peak rate times for an E7 tariff

At the moment our 8000kwh cost us £150 a month on Eon-Next's standard variable tariff .which is presently capped at 20.9p/kwh and 24p/day. I guess that your daytime tariff could be more expensive than ours and that your night-time one is probably a bit less.

Rather than relying on a guesstimate from EDF you need to do some careful  monitoring of your consumption, reading your meter at least once a month, sending that info into EDF and checking that your bills are using the readings. 

It helps if you can understand your energy profile over the year. You'll use significantly more in the winter than yo do in the summer

As I said, I use around 8000kwh a year which presently costs £1780.This averages out at 666.6kwh a month which is £148.33 rounded to £150 a month. However I use vastly varying amounts in each month as shown below

Jan - 1280kwh - costing £284 or about 16% of my annual average consumption and cost
Feb - 1040kwh - £231.00 or 13%
Mar - 960kwh   - £213.60 or 12%
Apr - 640kwh    - £142.40 or 8%
May - 400kwh   - £89.00 or 5%
Jun - 320kw     - £71.20 or 4%
Jul - 320kw      -  £71.20 or 4%
Aug - 320kw     - £71.20 or 4%
Sep - 320kw     - £71.20 or 4%
Oct - 560kwh   - £124.60 or 7%
Nov - 800kwh  - £178.00 or 10%
Dec - 1200kwh - £267.00 or 15%

By reading my meter monthly I can see if I'm roughly on target to balance my account over the year and can anticipate any shortfall or overpayment and do something about it

Astria

matelodave said:

A heatpump run at its optimum will deliver around 3kwh of heat for every 1 kwh of leccy, but as leccy is expensive so is the cost
of a kwh of heat - around 7p/kw in my case.

Although heatpumps may use less energy and can be more efficient than other forms of heating, they aren't cheaper to run. The cost of 1kwh of heat is more than mains gas, oil or possibly even LPG, but they are cheaper than other forms of electrical heating.

I also have a heatpump and an all electric bungalow and get through between 7000-8000kwh a year of which about 50% is for the heatpump and 50% for everything else.

For us (and I'd suspect for you as well) there's no advantage in being on an E7 tariff..There is no point in having cheaper night time leccy and paying more during the day if you cant take advantage of the cheaper rate.  I'm on a single rate tariff because the heatpump does most of its heating and we use most of our leccy during the peak rate times for an E7 tariff

At the moment our 8000kwh cost us £150 a month on Eon-Next's standard variable tariff .which is presently capped at 20.9p/kwh and 24p/day. I guess that your daytime tariff could be more expensive than ours and that your night-time one is probably a bit less.

Rather than relying on a guesstimate from EDF you need to do some careful  monitoring of your consumption, reading your meter at least once a month, sending that info into EDF and checking that your bills are using the readings. 

It helps if you can understand your energy profile over the year. You'll use significantly more in the winter than yo do in the summer

As I said, I use around 8000kwh a year which presently costs £1780.This averages out at 666.6kwh a month which is £148.33 rounded to £150 a month. However I use vastly varying amounts in each month as shown below

Jan - 1280kwh - costing £284 or about 16% of my annual average consumption and cost
Feb - 1040kwh - £231.00 or 13%
Mar - 960kwh   - £13.60 or 12%
Apr - 640kwh    - £142.40 or 8%
May - 400kwh   - £89.00 or 5%
Jun - 320kw     - £71.20 or 4%
Jul - 320kw      -  £71.20 or 4%
Aug - 320kw     - £71.20 or 4%
Sep - 320kw     - £71.20 or 4%
Oct - 560kwh   - £124.60 or 7%
Nov - 800kwh  - £178.00 or 10%
Dec - 1200kwh - £267.00 or 15%

By reading my meter monthly I can see if I'm roughly on target to balance my account over the year and can anticipate any shortfall or overpayment and do something about it

Is your March figure correct?

matelodave

Astria said:

matelodave said:

A heatpump run at its optimum will deliver around 3kwh of heat for every 1 kwh of leccy, but as leccy is expensive so is the cost
of a kwh of heat - around 7p/kw in my case.

Although heatpumps may use less energy and can be more efficient than other forms of heating, they aren't cheaper to run. The cost of 1kwh of heat is more than mains gas, oil or possibly even LPG, but they are cheaper than other forms of electrical heating.

I also have a heatpump and an all electric bungalow and get through between 7000-8000kwh a year of which about 50% is for the heatpump and 50% for everything else.

For us (and I'd suspect for you as well) there's no advantage in being on an E7 tariff..There is no point in having cheaper night time leccy and paying more during the day if you cant take advantage of the cheaper rate.  I'm on a single rate tariff because the heatpump does most of its heating and we use most of our leccy during the peak rate times for an E7 tariff

At the moment our 8000kwh cost us £150 a month on Eon-Next's standard variable tariff .which is presently capped at 20.9p/kwh and 24p/day. I guess that your daytime tariff could be more expensive than ours and that your night-time one is probably a bit less.

Rather than relying on a guesstimate from EDF you need to do some careful  monitoring of your consumption, reading your meter at least once a month, sending that info into EDF and checking that your bills are using the readings. 

It helps if you can understand your energy profile over the year. You'll use significantly more in the winter than yo do in the summer

As I said, I use around 8000kwh a year which presently costs £1780.This averages out at 666.6kwh a month which is £148.33 rounded to £150 a month. However I use vastly varying amounts in each month as shown below

Jan - 1280kwh - costing £284 or about 16% of my annual average consumption and cost
Feb - 1040kwh - £231.00 or 13%
Mar - 960kwh   - £13.60 or 12%
Apr - 640kwh    - £142.40 or 8%
May - 400kwh   - £89.00 or 5%
Jun - 320kw     - £71.20 or 4%
Jul - 320kw      -  £71.20 or 4%
Aug - 320kw     - £71.20 or 4%
Sep - 320kw     - £71.20 or 4%
Oct - 560kwh   - £124.60 or 7%
Nov - 800kwh  - £178.00 or 10%
Dec - 1200kwh - £267.00 or 15%

By reading my meter monthly I can see if I'm roughly on target to balance my account over the year and can anticipate any shortfall or overpayment and do something about it

Is your March figure correct?

Sorry about that it should be £213.60 - the 2 got missed. Well spotted  . I've sorted it out

Damob123

Hey,

Thanks for getting back to me - always great to get some clarity on these things. 

So to answer both your questions:

- Had the heat pump for 12 months. I got it installed whilst the RHI scheme was running (I'm not sure if it still is?)
- I do have arrears yes. GNE previously had me on abit of a rubbish tariff, which left me owing EDF £500 when they went into administration and transferred me to EDF. My latest bill with EDF (published 5 days ago suggests I'm in debit of £250)
- My smart meter has suggested between £80 - £125 per month since October (bearing in mind that it's getting colder now).
- I believe I'm now on what's called 'Deemed Economy 7'. I was previously on 'GNE Variable v5 (E7)' if that means anything to you?
- The house ranges from 16 - 18.5 degrees depending on the time of day. That's the whole house, although we could technically go even lower upstairs if needed, as we don't use it during the day. 
- The walls are all cavity insulated. The loft has about 300mm+ in there. We also have a single storey flat roof extension with 125mm of Kingspan insulation.
- kWh rate is 23.7p during the day, and 10.93p at night on this new 'Deemed' tariff. 

I really appreciate the help and advice here. I'm new to this Air Source Heat Pump, so just trying to figure out whether A. I need to insulate better somewhere in the house, B. Have a chat with my energy provide, C. Sit tight as I'm actually doing ok considering the energy prices at the moment. 

Thanks again!

Verdigris

What does your EPC say the heating requirement is? You can look it up online, if you don't have it to hand? Also what power rating is the heat pump and what is the SCOP (that will be on your RHI calculation)?

Reed_Richards

Verdigris said:

.... what is the SCOP (that will be on your RHI calculation)?

It should be stated on your MCS certificate, along with other figures for your heating and hot water requirements (which may differ from those on your EPC).