The shockingly unkempt Patrick Harvie has been voted “Zoomer of the Week” on The Majority Show for his looney green policies on heat pumps, starts at 59:30 on https://www.youtube.com/watch?v=6lFMle3rJV8.
It’s an amusing take-down, with interesting comments from the Delvins who have experience of heat pumps from living abroad, confirming that heat pumps are very noisy and saying that they had to have two because one wasn't enough to heat the house.
I thought they'd just dragged a rough sleeper off the streets into the studio as a stand-in! But smart dressed or looking like a tramp, it matters not; he's still a complete idiot and he's upsetting all the wrong people by the looks of it.
From a purely economic point of view ignoring the capital cost of supply and installation the COP is still above 1 even at -15C. So, if you were using electricity for heating the running cost of the heat pump still comes out ahead. Depending on the cost of gas it may or may not be cheaper to run depending on the cost of gas. If you’ve got cheap gas it’s a no brainer, you use gas, it’s simple and effective for heating, using fire to heat stuff was mastered a long time ago but always has a “COP” <= 1. With heat pumps the problem isn't so much that it’s inefficient at low temperature it’s still more efficient than gas as long as the COP > 1, it’s more a capacity issue. If you’re happy spending the money on a larger unit (greater capacity) it’s not a problem, it’s will probably be oversized but that essentially only effects the initial purchase price and installation i.e if you size the unit for -15C to deliver say 2.6kW of heating to raise the water to 65C it will use 2kW of electrical power. The same unit will only use about half (1.3/2.3) to do the same job when it’s 7C outside. I’m not sure how they size the units in the UK, here in Australia it’s not such a big deal as the temperature difference between summer and winter is not as extreme. From the chart a 2.7kW “water heater” rated to produce hot water at 55C with an outside air temp of 7C will only heat the water to 35C when it’s -2C outside. I’ve just used the easiest example as it’s the only bars with the same COP. This assumes you can actually get units that go down to -15C, I have no practical experience using heat pumps operating at such a low outside air temperature, I assume they use electrical de-icing or hot gas by-pass to prevent the coils freezing and it’s part of the COP calculation that’s why the COP is so bad at -15C. If the COP is only being calculated using the refrigerant cycle (ignoring the de-icing) then it gets even worse. I’m a big fan of heat pumps but they won’t work as expected if they’re sized wrong and the end user will be disappointed with the result if it’s not explained them properly.
The problem is, electricity in the UK is 3 times the cost of gas, so you're looking at a COP of 3-5 just to break even on the running costs. Then there's the fact that most air source heat pumps in the UK will be replacing combi gas boilers and so will be used for heating water, which even at the best of times, they are only going to manage just over 50C, which means that more efficient, larger radiators will be needed, adding greatly to the capital costs. Domestic hot water for showers/baths will probably need to be heated directly via electric, so that's an added cost, because of the price of electricity vs. gas. The combined physics and economics just don't stack up in favour of heat pumps in the UK, considering the climate, energy costs and the widespread popularity of gas-fired central heating and domestic hot water systems.
In my part of Scotland it doesn't get below freezing that often - the effects of the north atlantic drift. However, it does get mighty cold in the Highlands.
The analyses above don't consider the efficiencies of generating electricity and transmitting it to a putative heat pump.
Using natural gas to make electricity is just plain stupid from an environmental point of view: "... all such conventional primary energy sources (coal, oil, gas, nuclear) are not as efficient – it is estimated that natural gas plants convert around 45% of the primary input, into electricity, resulting in “only” 55% of energy loss, whereas a traditional coal plant may loose up to 68%." (https://www.future-energy-partners.com/post/energy-losses-in-power-generation)
So you have a 50% loss of efficiency at that point. Then there's long-distance transmission which loses another third of the energy. So we end up with around one third of what we would have got had we just burned the gas in our boilers.
So to break even you need to achieve a COP of 3.
Why can't our political numpties see this? (Oh, I've answered my own question).
When a company breaks its vested interest to advise AGAINST buying its product for the wrong purpose, we're seeing a unique and heroic example of honesty and courage!!!
The UK government has set a ludicrous target of installing heat pumps in 600,000 homes per year but so far has achieved a trickle, only 9,000 over a recent 3-month period according to Ross Clark despite the £5k bung, due to expire in 2025. Suppliers may go on strike for fear of being fined for not meeting government quotas: https://www.telegraph.co.uk/news/2023/06/05/the-tories-are-staking-our-future-on-technology-we-know-won/.
A report published in May shows the installations per 1,000 households across regions of the UK. Surprisingly, Scottish islands top the list, e.g. 120 in Orkney. In contrast, most areas are much, much lower, e.g. 3 in St Albans, 0.3 in Wolverhampton: https://www.telegraph.co.uk/news/2023/05/20/head-pump-noise-disturbance-complaints/.
Control freak Patrick Harvie will have to eat crow and back down on his authoritarian plans as most people want nothing to do with noisy, expensive heat pumps which for many homes simply aren’t up to the job.
I've got an awesome Mitsubishi Mr. Slim A/C-heat pump and three wall units in my house. We use it primarily for cooling as July and August are absolutely terrible months here. Works great.
For heat however, they also work 'ok' to take the chill off nights around 45-50 degrees and they also cost a small fortune to run. We use a woodstove as primary heat with a oil fired boiler/baseboard heat for real winter.
Heat pumps absolutely do not function below freezing... at ... all.
It is amusing the lengths you will go to defend the fossil fuel industry. I guess Norway must have a much more temperate climate than Scotland given how many heat pumps have been installed and successfully operated there
An absurd and terribly misleading quote from that article,
"....Heat pumps, which can operate at external temperatures of -25C (-13F) and provide hot water at 65C (149F),..."
There's no common residential electric air to air heatpump that can accomplish that. In conjunction with a deep geothermal hydro- loop perhaps that's true which is kinda why the author is hedging/lying when they specify "air to air" as a type of pump but fail to expand upon that.
Geothermal can extend heatpump usage to a point below freezing temps but is site dependent(lots of land and diggable soils required) and tremendously expensive/complex to install.
Ground source heat pumps are a lot more efficient in cold weather, but 90% of heat pumps installed in Norway are air source, and a majority of those are air to air. Air to water heat pumps really struggle in cold weather to heat water. The reason being, water has a much higher specific heat capacity than air. This is why Haughey warns about Legionnaire's disease in water only heated to barely lukewarm temperatures (35C).
I still don't see from a physics standpoint using common hvac components that air to air pumps will work much below 32f or 0c.... Below 15f? Single digit fahrenheit? nfw....
Norway temps are far milder than I'd have suspected from a quick search.
I would suspect the only way an air to air heat pump (using off the shelf hvac components/refrigerants) is going to ever function sub 15F is through some kind of direct-heating coil in the compressor unit which in terms of efficiency is peak absurdity..... Or perhaps in the case of the split-type Mitsubishi unit I've got with the pump outside and remote wall units you could theoretically put a high wattage heating coil in the wall units (like a space heater/baseboard electric). But that's not really a "heat pump" anymore...
Hmm, yes, you would know more about this than the manufacturer of course. Norway uses a majority of AAHPs (air to air heat pumps) for simple space heating. In Britain, AWHPs (air to water) would mainly be used to replace central heating boilers and this would mean the extra expense of installing new radiators. Also, Norway has plentiful, cheap hydroelectric power. The UK doesn't. But about the efficiency of air source heat pumps in cold climates:
"However, the COP [coefficient of performance] of ASHPs decreases significantly at lower temperatures [44]. Figure 12 shows the COP of a type of ASHP (Panasonic T-CAP 9 kW) for different water temperatures and outdoor air temperatures. While most ASHP companies report a COP value in the range of 4–5, Figure 12 shows that with water at 35 °C, COP can decrease from 4.6 to 2.5 when the outdoor air temperature decreases from + 7 °C to − 15 °C. This should be noted that the water at 35 °C can be good enough for under-floor heating, but for heating radiators, the water temperature should increase to 65 °C, and for those temperatures, we notice that the COP decreases almost to 1.3 for an outdoor air temperature of − 15 °C [44].
An experimental study for ASHP (air-to-water) indicated that the efficiency of the heat pump unit depends upon outdoor air temperature. Analysis showed system consumed minimum time to achieve the designed water temperature (20 °C-50 °C) when the ambient temperature was at 30 °C, while it took more time to reach at aimed temperature when the air temperature fell to 5 °C. Furthermore, the heating time duration for the air temperature at 5 °C was extended from 5 to 12 h to achieve the designed water temperature for the system [45]. The ASHP system includes an outdoor unit, which utilizes heat for the unfreezing process during cold days and significantly reduces COP."
For heating radiators in Scotland in freezing winter weather, ASHPs would be next to useless.
- Sorry if i missed it but your quote "However, the COP [coefficient of performance] of ASHPs decreases significantly ..." refers to graphs which I can't see.
- The article referred to by Herb points out that "... Norway’s embrace of heat pumps eventually arrived, fuelled by government subsidies, high fossil fuel taxes, low electricity rates and restrictions on oil boilers (which have been banned since 2020)...." which could at least in part explain its dash to adopt this technology.
- I think you're right to be sceptical of salesman's claims. I got a domestic Solar PV installation about 12 years ago (who could resist such a huge bribe?). It's averaged 4.94kWh/day which is about 84% of what was predicted by the installer based on latitude/aspect/tree shading etc.
The shockingly unkempt Patrick Harvie has been voted “Zoomer of the Week” on The Majority Show for his looney green policies on heat pumps, starts at 59:30 on https://www.youtube.com/watch?v=6lFMle3rJV8.
It’s an amusing take-down, with interesting comments from the Delvins who have experience of heat pumps from living abroad, confirming that heat pumps are very noisy and saying that they had to have two because one wasn't enough to heat the house.
I thought they'd just dragged a rough sleeper off the streets into the studio as a stand-in! But smart dressed or looking like a tramp, it matters not; he's still a complete idiot and he's upsetting all the wrong people by the looks of it.
From a purely economic point of view ignoring the capital cost of supply and installation the COP is still above 1 even at -15C. So, if you were using electricity for heating the running cost of the heat pump still comes out ahead. Depending on the cost of gas it may or may not be cheaper to run depending on the cost of gas. If you’ve got cheap gas it’s a no brainer, you use gas, it’s simple and effective for heating, using fire to heat stuff was mastered a long time ago but always has a “COP” <= 1. With heat pumps the problem isn't so much that it’s inefficient at low temperature it’s still more efficient than gas as long as the COP > 1, it’s more a capacity issue. If you’re happy spending the money on a larger unit (greater capacity) it’s not a problem, it’s will probably be oversized but that essentially only effects the initial purchase price and installation i.e if you size the unit for -15C to deliver say 2.6kW of heating to raise the water to 65C it will use 2kW of electrical power. The same unit will only use about half (1.3/2.3) to do the same job when it’s 7C outside. I’m not sure how they size the units in the UK, here in Australia it’s not such a big deal as the temperature difference between summer and winter is not as extreme. From the chart a 2.7kW “water heater” rated to produce hot water at 55C with an outside air temp of 7C will only heat the water to 35C when it’s -2C outside. I’ve just used the easiest example as it’s the only bars with the same COP. This assumes you can actually get units that go down to -15C, I have no practical experience using heat pumps operating at such a low outside air temperature, I assume they use electrical de-icing or hot gas by-pass to prevent the coils freezing and it’s part of the COP calculation that’s why the COP is so bad at -15C. If the COP is only being calculated using the refrigerant cycle (ignoring the de-icing) then it gets even worse. I’m a big fan of heat pumps but they won’t work as expected if they’re sized wrong and the end user will be disappointed with the result if it’s not explained them properly.
The problem is, electricity in the UK is 3 times the cost of gas, so you're looking at a COP of 3-5 just to break even on the running costs. Then there's the fact that most air source heat pumps in the UK will be replacing combi gas boilers and so will be used for heating water, which even at the best of times, they are only going to manage just over 50C, which means that more efficient, larger radiators will be needed, adding greatly to the capital costs. Domestic hot water for showers/baths will probably need to be heated directly via electric, so that's an added cost, because of the price of electricity vs. gas. The combined physics and economics just don't stack up in favour of heat pumps in the UK, considering the climate, energy costs and the widespread popularity of gas-fired central heating and domestic hot water systems.
In my part of Scotland it doesn't get below freezing that often - the effects of the north atlantic drift. However, it does get mighty cold in the Highlands.
The analyses above don't consider the efficiencies of generating electricity and transmitting it to a putative heat pump.
We use a lot of natural gas here in the UK to generate electricity: for sep-nov 2022 "Gas provided 42.6% of electricity generation by Major Power Producers, with renewables at 40.5%, nuclear at 14.5% and coal at 1.6%" (https://www.gov.uk/government/statistics/energy-trends-and-prices-statistical-release-26-january-2023)
Using natural gas to make electricity is just plain stupid from an environmental point of view: "... all such conventional primary energy sources (coal, oil, gas, nuclear) are not as efficient – it is estimated that natural gas plants convert around 45% of the primary input, into electricity, resulting in “only” 55% of energy loss, whereas a traditional coal plant may loose up to 68%." (https://www.future-energy-partners.com/post/energy-losses-in-power-generation)
So you have a 50% loss of efficiency at that point. Then there's long-distance transmission which loses another third of the energy. So we end up with around one third of what we would have got had we just burned the gas in our boilers.
So to break even you need to achieve a COP of 3.
Why can't our political numpties see this? (Oh, I've answered my own question).
If that’s the case then it sounds like a pretty stupid idea for multiple reasons.
When a company breaks its vested interest to advise AGAINST buying its product for the wrong purpose, we're seeing a unique and heroic example of honesty and courage!!!
I hope so.
British Gas agrees with heat pump supplier Lord Haughey, saying they will only agree to install a heat pump if convinced that it will succeed in getting the property up to a target temperature on the coldest days: https://www.telegraph.co.uk/news/2023/05/12/the-heat-pump-farce-has-finally-been-exposed/.
The SNP/Greens should have learned from Sturgeon’s experience in converting her official residence Bute House to heat pumps, at a cost of £800k: https://www.express.co.uk/news/uk/1542230/nicola-sturgeon-scotland-bute-house-electric-heaters-800k-ont.
The German Greens are reported to have spent 5 million Euros converting their HQ to heat pumps: https://wattsupwiththat.com/2023/06/14/german-green-party-headquarters-heat-pump-debacle-5-million-euros-cost-still-no-heat/.
The UK government has set a ludicrous target of installing heat pumps in 600,000 homes per year but so far has achieved a trickle, only 9,000 over a recent 3-month period according to Ross Clark despite the £5k bung, due to expire in 2025. Suppliers may go on strike for fear of being fined for not meeting government quotas: https://www.telegraph.co.uk/news/2023/06/05/the-tories-are-staking-our-future-on-technology-we-know-won/.
A report published in May shows the installations per 1,000 households across regions of the UK. Surprisingly, Scottish islands top the list, e.g. 120 in Orkney. In contrast, most areas are much, much lower, e.g. 3 in St Albans, 0.3 in Wolverhampton: https://www.telegraph.co.uk/news/2023/05/20/head-pump-noise-disturbance-complaints/.
The UK’s roll-out of heat pumps is the lowest in Europe: https://www.telegraph.co.uk/business/2023/04/13/flagship-heat-pump-scheme-flops-installations-target/.
Control freak Patrick Harvie will have to eat crow and back down on his authoritarian plans as most people want nothing to do with noisy, expensive heat pumps which for many homes simply aren’t up to the job.
I've got an awesome Mitsubishi Mr. Slim A/C-heat pump and three wall units in my house. We use it primarily for cooling as July and August are absolutely terrible months here. Works great.
For heat however, they also work 'ok' to take the chill off nights around 45-50 degrees and they also cost a small fortune to run. We use a woodstove as primary heat with a oil fired boiler/baseboard heat for real winter.
Heat pumps absolutely do not function below freezing... at ... all.
https://reasonstobecheerful.world/heat-pumps-norway-efficiency-emissions/
It is amusing the lengths you will go to defend the fossil fuel industry. I guess Norway must have a much more temperate climate than Scotland given how many heat pumps have been installed and successfully operated there
An absurd and terribly misleading quote from that article,
"....Heat pumps, which can operate at external temperatures of -25C (-13F) and provide hot water at 65C (149F),..."
There's no common residential electric air to air heatpump that can accomplish that. In conjunction with a deep geothermal hydro- loop perhaps that's true which is kinda why the author is hedging/lying when they specify "air to air" as a type of pump but fail to expand upon that.
Geothermal can extend heatpump usage to a point below freezing temps but is site dependent(lots of land and diggable soils required) and tremendously expensive/complex to install.
Ground source heat pumps are a lot more efficient in cold weather, but 90% of heat pumps installed in Norway are air source, and a majority of those are air to air. Air to water heat pumps really struggle in cold weather to heat water. The reason being, water has a much higher specific heat capacity than air. This is why Haughey warns about Legionnaire's disease in water only heated to barely lukewarm temperatures (35C).
I still don't see from a physics standpoint using common hvac components that air to air pumps will work much below 32f or 0c.... Below 15f? Single digit fahrenheit? nfw....
Norway temps are far milder than I'd have suspected from a quick search.
I would suspect the only way an air to air heat pump (using off the shelf hvac components/refrigerants) is going to ever function sub 15F is through some kind of direct-heating coil in the compressor unit which in terms of efficiency is peak absurdity..... Or perhaps in the case of the split-type Mitsubishi unit I've got with the pump outside and remote wall units you could theoretically put a high wattage heating coil in the wall units (like a space heater/baseboard electric). But that's not really a "heat pump" anymore...
What do you make of the news that the Government is preparing to bin the Nut Zero AGW-hoax inspired economic suicide project, Herb?
"Rishi Sunak grants hundreds of new North Sea oil and gas licences"
https://www.telegraph.co.uk/politics/2023/07/31/sunak-approves-oil-gas-drilling-homegrown-energy-climate/
"Oil on course for biggest monthly gain since early 2022"
https://www.telegraph.co.uk/business/2023/07/31/ftse-100-market-latest-news-inflation-north-sea-oil-gas/
Or the appointment of a new head of the IPCC and his condemnation of climate alarmists?
"Don't overstate 1.5 degrees C threat, new IPCC head says"
https://www.dw.com/en/climate-change-do-not-overstate-15-degrees-threat/a-66386523
"Ignore the doom-mongers, says new UN climate change chief"
https://www.telegraph.co.uk/news/2023/07/31/climate-doommongers-do-more-harm-than-good-says-un-chief/
Hmm, yes, you would know more about this than the manufacturer of course. Norway uses a majority of AAHPs (air to air heat pumps) for simple space heating. In Britain, AWHPs (air to water) would mainly be used to replace central heating boilers and this would mean the extra expense of installing new radiators. Also, Norway has plentiful, cheap hydroelectric power. The UK doesn't. But about the efficiency of air source heat pumps in cold climates:
"However, the COP [coefficient of performance] of ASHPs decreases significantly at lower temperatures [44]. Figure 12 shows the COP of a type of ASHP (Panasonic T-CAP 9 kW) for different water temperatures and outdoor air temperatures. While most ASHP companies report a COP value in the range of 4–5, Figure 12 shows that with water at 35 °C, COP can decrease from 4.6 to 2.5 when the outdoor air temperature decreases from + 7 °C to − 15 °C. This should be noted that the water at 35 °C can be good enough for under-floor heating, but for heating radiators, the water temperature should increase to 65 °C, and for those temperatures, we notice that the COP decreases almost to 1.3 for an outdoor air temperature of − 15 °C [44].
An experimental study for ASHP (air-to-water) indicated that the efficiency of the heat pump unit depends upon outdoor air temperature. Analysis showed system consumed minimum time to achieve the designed water temperature (20 °C-50 °C) when the ambient temperature was at 30 °C, while it took more time to reach at aimed temperature when the air temperature fell to 5 °C. Furthermore, the heating time duration for the air temperature at 5 °C was extended from 5 to 12 h to achieve the designed water temperature for the system [45]. The ASHP system includes an outdoor unit, which utilizes heat for the unfreezing process during cold days and significantly reduces COP."
For heating radiators in Scotland in freezing winter weather, ASHPs would be next to useless.
- Sorry if i missed it but your quote "However, the COP [coefficient of performance] of ASHPs decreases significantly ..." refers to graphs which I can't see.
- The article referred to by Herb points out that "... Norway’s embrace of heat pumps eventually arrived, fuelled by government subsidies, high fossil fuel taxes, low electricity rates and restrictions on oil boilers (which have been banned since 2020)...." which could at least in part explain its dash to adopt this technology.
- I think you're right to be sceptical of salesman's claims. I got a domestic Solar PV installation about 12 years ago (who could resist such a huge bribe?). It's averaged 4.94kWh/day which is about 84% of what was predicted by the installer based on latitude/aspect/tree shading etc.
Apologies. I forgot to link to the article:
https://www.sciencedirect.com/science/article/pii/S2213138822008773#s0055
I've added the graph to the end of the article now.