Heat Pump Running Cost Poor Reporting And Misinformation

[PhilT]

Currently BBC news have an article "Heat pump growth stalls as government support cut, warns climate watchdog". Not surprising! Even the BBC itself is guilty, for example Evan Davis published an article recently:

"Heat pumps work for me - but they're not yet a money saver" https://www.bbc.co.uk/news/articles/ce358gkx9vpo

In it the cost of electricity for a heat pump is quoted as 28p/kWh! I complained to the BBC about not reporting the obvious fact that much cheaper heat pump tariffs are available, and got a response asking for evidence of this! So could we do a little survey of our forum members. What average variable rates are people in this forum currently achieving over the course of the last 12 months (or for 2025 if easier), for imported electricity for their heat pumps? Mine was 18p/kWh average for 2025 using Octopus Cosy.

[Dillsue]

We run ours on Octopus Go currently 5 hours at 8.5p and the rest at 32p.

 

The whole official drive to heat pumps is utter bollocks. We've just had our EPC redone pre sale and the asessor told me that heat pumps can be less efficient than a gas boiler and our EPC reflects this. Apparently within SAP if you enter the heating as a heat pump with radiators it defaults to 55 degree flow temp with drops the HP efficiency. Having explained our over sized radiators and max 34 degree flow temp he just shrugged his shoulders!

 

The EPC came through with an estimated 28000 kwh needed for heating versus the actual 3800 we used last winter to keep the house at 20/21 degrees! It's bonkers

[FarmerN]

Also Octopus cosy, rarely pay more than 14p/unit  but also have battery so increases amount of time we can use “ Off Peak”.  Maybe  allow 2p/unit for inefficiency of going through battery.

Lowest COP in winter was 5  ( GSHP )  so a cost of about  3p/kW of heat or less.

No sure what sort of COP ASHPs average in winter.

 

We used 1800kWh electricity via heat pump in 6 months October - March for hot water and heating for our 200SqM new build bungalow, kept very warm. 

Edited 10 hours ago by FarmerN

[Bramco]

We imported 11,100kWh at a cost of £1009. So the princely sum of 9p/kWh on average.   Exported £840 worth of kWh, so ran the house for £160 for the full year. (6.5kW Solar and 15kWh of battery, 9kW ASHP.)   Given the standing charge is about 50p, the difference between import and export is about zero.  We have no gas, so this is all our energy usage, heating, cooking, hot water etc.

 

But this is for a 250 m2 timber frame house (almost passiv haus levels of insulation) with a UFH built into the insulated slab. All our heating is done by batch charging the slab at night on the cheap rate on Octopus Go with occasional daytime boosts when it's really cold.

Our off peak usage is normally close to 100%.

Trystan Lea at Open Energy Monitor has recently created a tool to show the co-benefits of  solar, battery, HP and ev on the agile tariff makes interesting reading  https://community.openenergymonitor.org/t/what-are-the-co-benefits-of-solar-battery-hp-ev-tariff/30095

[SimonD]

1 hour ago, PhilT said:

Currently BBC news have an article "Heat pump growth stalls as government support cut, warns climate watchdog". Not surprising! Even the BBC itself is guilty, for example Evan Davis published an article recently:

"Heat pumps work for me - but they're not yet a money saver" https://www.bbc.co.uk/news/articles/ce358gkx9vpo

In it the cost of electricity for a heat pump is quoted as 28p/kWh! I complained to the BBC about not reporting the obvious fact that much cheaper heat pump tariffs are available, and got a response asking for evidence of this! So could we do a little survey of our forum members. What average variable rates are people in this forum currently achieving over the course of the last 12 months (or for 2025 if easier), for imported electricity for their heat pumps? Mine was 18p/kWh average for 2025 using Octopus Cosy.

TBH, I think the article by Evan Davis was pretty fairly balanced, and the BBC the other BBC one is slightly cheaky as it doesn't properly go into why the ECO4 grant was amended. The reality is that if the heat pump is going in as a retrofit, the overall costs of the system are very high - and no, unlike many incorrect claims here on this forum, this is not purely down to grant harvesting. But figures like Dale Vince aren't helping by saying things like heat pumps don't work like they say they do, as he did in an interview yesterday, doesn't help at all. These are the kinds of statements that need clarifying, but just like the whole Net Zero thing, the general and popular coverage is fairly toxic and I have to say the industry isn't helping itself greatly right now.

[ProDave]

I prefer to keep things simple and assume a heat pump will cost about the same as gas as long as you can achieve a COP or 3 or better.  Yes with TOU tariffs you can do better but that means running your heating at the cheap times not "when you want" which will work with a well insulated house and an UFH slab with a bit of mass.  But no use pedalling that off peak usage option to someone retro fitting an ASHP to a mediocre house that does need the ASHP on at times when you need heating.

 

If you do insist on a competition of "look how cheap mine is to run" then all you do is build up a lot more disappointed convertees when they can't time shift the usage in their mediocre house.

 

So keep those ideas here for those with good houses, not for the mass market without.

[JohnMo]

Thing often missed when comparing gas to heat pumps, is the gas standing charge goes without gas CH (maybe a hob change also). 

 

 

[ProDave]

We have LPG in bottles for the hob, no standing charge and usage is so low, gas cost is irellevant.

[Beelbeebub]

3 hours ago, Dillsue said:

We run ours on Octopus Go currently 5 hours at 8.5p and the rest at 32p.

 

The whole official drive to heat pumps is utter bollocks. We've just had our EPC redone pre sale and the asessor told me that heat pumps can be less efficient than a gas boiler and our EPC reflects this. Apparently within SAP if you enter the heating as a heat pump with radiators it defaults to 55 degree flow temp with drops the HP efficiency. Having explained our over sized radiators and max 34 degree flow temp he just shrugged his shoulders!

 

The EPC came through with an estimated 28000 kwh needed for heating versus the actual 3800 we used last winter to keep the house at 20/21 degrees! It's bonkers

The EPC system is pretty crap. 

 

I just had an all electric flat done - got a poor E score, mainly because of direct electric heating and hot water. 

 

The assessor model 2 options for me. Swap to air to air HP or new high heat retention storage Heaters. 

 

They both came out the same points, despite the HP option using 1/3 the electricity. 

 

Shrugs. 

[Dreadnaught]

Have a heat pump but no PV or battery. Octopus Agile since 1 April 2026.

 

Average unit rate consumed: 13.9 p/kWh.

 

(I schedule the heat pump to be off in peak periods.)

[Benpointer]

1 hour ago, Beelbeebub said:

The EPC system is pretty crap. 

 

I just had an all electric flat done - got a poor E score, mainly because of direct electric heating and hot water. 

 

The assessor model 2 options for me. Swap to air to air HP or new high heat retention storage Heaters. 

 

They both came out the same points, despite the HP option using 1/3 the electricity. 

 

Shrugs. 

How would 'high-retention storage heaters' make any difference?    Electricity in = heat out eventually no matter how high the retention surely?

[Beelbeebub]

54 minutes ago, Benpointer said:

How would 'high-retention storage heaters' make any difference?    Electricity in = heat out eventually no matter how high the retention surely?

Yeah, but the idea is they don't leak the heat away during the day when you're out and then be spent in the evening requiring you to use fan heaters. 

 

Storage heaters are a shit idea based on the old idea of "spare" elec always going free at night. Which was true in the days of big coal plants. Less so with renewables, batteries, ev's etc. 

. But there we go.  This is the official EPC system that we are forced to adhere to. 

 

I get about half as much effect on my epc for replacing all the single glazed windows with double glazing as I do by just swapping the panel heaters to HHR units....