From NOT A LOT OF PEOPLE KNOW THAT
By Paul Homewood
Following on from the post about heat pumps, I thought I would have a look at their impact on electricity demand.
My analysis reckoned on a typical household consumption of 3857 KWh with a heat pump. If we assume that they will only be used for heating for six months every year, that equates to 643 KWh a month, or 21 KWh a day.
At the coldest times of year, that average will increase substantially, so we could well be looking at 30 KWh a day then, since the heat pump will have to work much harder.
Although heat pumps are designed to provide low level heat continuously, I suspect that many will turn them off at night because it is too warm to sleep. We usually have our bedroom windows open all winter at night!
If we assume then that the heat pumps are in use for 14 hours a day, that gives average hourly electricity demand of 2.1 KWh. This assumes that the heat pump runs at a constant power rating. In practice, the system would have to work harder in the early evening as temperatures drop.
There are about 24 million homes with gas and oil boilers, so a peak demand of 2.1 KW amounts to 50 GW for the country as a whole. To that we can add demand from offices, shops etc, which currently use gas and oil.
Along with demand from EVs, the UK would need well over 100 GW of capacity to meet peak demand.
This is all twenty years or more away. But if the government’s target of 600,000 heat pumps a year is met, even within the next ten years, we will be needing at least 13 GW of extra grid capacity, at a time when dispatchable power generation is being shut down.
Can’t wait for rationing to require the heat pumps controller to automatically shut off if they’re not running at greater than 60% of their capacity… which is literally most of the time they’re actually needed.
Smart meters can already do this! It is a plot.
“”designed to provide low level heat””
I’m sorry, but that – and a lack of hot water – just isn’t good enough. Besides there isn’t any where to put a tank.
Oh dear, WUWT may be the ‘most viewed’ climate website but it’s the one that’s = ‘least read’ – even by its own subscribers
as attached – where all the calculations here go straight out of the window by a factor of two
From here
OK, the numbers apply to Germany but let’s be clear that large parts of Germany are subject to the idyllic Mediterranean Climate.
i.e Heat demand supplied by heatpumps in Germany would equate to an electricity demand of between 7 and 8 thousand kWh per year despite that year-round toasty warmth.
Take that as 20kWh daily and is 250% higher than what UK Government dreamily imagines a typical UK home consumes presently (hence the figures used for setting the ‘price cap)
And an EV, for every 1,000 annual miles it’s driven, will demand/consume an extra 1 kWh daily
Consider, as insurance companies do, that typical UK drivers go 10,000 miles annually so electricity consumption becomes 500% of what it is now.
and the ‘now’ figure is an absolute joke – a very bad one at that.
Well no-one has ever accused Main Stream Media of either proofreading their articles prior to print or verifying the veracity of the claims they Proffer as accurate
I’m sorry Peta, but your geography is a bit out:-
“large parts of Germany are subject to the idyllic Mediterranean Climate”
Have you forgotten about the Alps?
I gave up trying to figure out where she was talking about. I’ve been to Germany five or six times and every time it was winter and darn cold.
The article doesn’t mention EVs so although interesting is not relevant to the discussion.
You could say some of the assumptions are wrong, I manually control the heating, and certainly don’t have windows open at night in winter. Most houses I’ve lived in have had enough drafts to mean there’s enough ventilation.
A lot of British houses have both CH and room heating not sure how that is going to affect the calculation
Liter of heating oil is about 10.7 kWh, and in the country probably most detached houses do around 2,000 liters a year. Some more, some less. So that is about 21,500 kWh per house.
But the critical factor is going to be instantaneous demand, as in come home, turn on the heating and charge the car. Right now the UK peak is about 45GW. Paul estimates it will rise to “well over 100GW”. Yes, that seems like quite a conservative estimate. Probably 150GW is more likely.
Then ask, if your wind parc often does under 10% of faceplate for days on end, how much wind you need to cover that? Not rocket science, its going to be “well over’ 1,000GW. The UK now has 28GW. Ain’t going to happen.
And this is not mentioning the local transmission networks. You can see these baby transformers all over the UK in fields near villages. All have to be rebuilt.
‘The UK now has 28GW. Ain’t going to happen.’
No, it ain’t. And given the likely need for additional thermal generation to reliably meet the much higher electric ‘demand’ stemming from mandated heat pumps and EVs, I hope the planners are taking the 2nd LoT, as well as line losses, into account when they calculate their emissions ‘reductions’.
I’m sure they are not. They are not planning for the storage that will be needed to make any transition to wind possible. They have no plans for getting installed anything close to the necessary amount of wind. Nor are they planning for the local network upgrades. Its not going to happen, the only real question is which cracks first, the electricity network or Net Zero. I am afraid it is quite likely they will press on regardless, mandate lots of Net Zero measures in isolation without thinking it all through, and the result will be a mixture of power rationing and blackouts.
You can see the completely disconnected mentality in the latest proposed tax on boiler manufacturers, basically a penalty tax on oil or gas boilers to drive everyone to heat pumps. Slap a quota on oil or gas boilers, then a tax on every one made over quota. But this does nothing to make heatpumps work any better, cost any less to run. It does nothing about the local network lack of capacity. And it does nothing about the lack of tradesmen to install the things. And then you have the lack of power due to the move to wind, so even overcome all the other things and the country is still not going to be able to run the EVs and heat pumps. At least, not via Net Zero.
They have also forgotten that the UK has over 300,000 low voltage substations with around 1m feeders and 450,000kms of buried cable. Some 80% of this is built for ‘lighting plus’ and not the load associated with EVs and heat pumps and will probably have to be replaced.This will involve digging up most of the non motorway roads in the country which some time ago was estimated to cost £60bn.
https://v2g.co.uk/2021/05/electric-vehicles-as-energy-smart-applianc es/
https://v2g.co.uk/2021/05/electric-vehicles-as-energy smart-appliances
I’ll get this right eventually 🙂
https:v2g.co.uk/2021/05/electric-vehicles-as-energy-smart-appliances
Not my day!!!
https:v2g.co.uk/2021/05’electric-vehicles-as-energy-smart-appliances/
https://v2g.co.uk/2021/05/electric-vehicles-as-energy-smart-appliances/
Thanks- brain fart I think!
Yes, that’s what I meant by the ‘baby transformers’. Walk observantly around any English village and you’ll find several. Sometimes at the edge of a field, sometimes in a scrap of land fenced off from a house garden. Always visible from the road. Then take a look overhead at the mains cable supply going down the small roads to houses and farms. No way is this going to handle everyone moving to EVs and heat pumps.
The funny thing (not really funny) is that those who have the space to install a heat pump and a drive to charge an EV without running cable across the pavement are exactly the ones living in places where the local substations and cabling cannot support them all doing that!
It reminds one of ‘Yes Minister’, the one where Hacker discovers the idea of that old chesnut the integrated transport policy, to Sir Humphrey’s barely concealed amusement. There must be ministers today who are rediscovering the idea of the integrated energy policy, to the barely concealed snickers of their civil service departments who then explain to the latest incumbent why such an attractive and commonsense idea is still, as it always has been, impossible and out of the question.
£60 billion is nothing, it is much, much more than that. To replace street cables costs about £100/m, and HV cables (you need that too) around £200/m. It is very disruptive to traffic, and we don’y have the workforce anyway. As fitting larger cables doesn’t really work (difficult stuff bulk electricity) you need to put 2 or 3 or 4 cables, (spaced out because of heat) where the was one before to meet a load of say 6kW continuous for each dwelling. I think the real cost would be more like £5-10k per dwelling, times 25 million, not including the cost of rebuilding pavements, other services and roads. More substations on land that we don’t have would double that cost, and the HV services probably add a similar amount again. It has been estimated at £5Trillion total, obviously impossible (or it would triple the National Debt, and bankrupt the Government very quickly, along with the rest of us).
The town where I live in the UK has a population of about 10,000. The electricity network people have just upgraded the supply to the town doubling the capacity. This is partly to supply the extra houses being built at the moment and partly in preparation for net zero. The cost of this upgrade is £10,000,000. That is about £1,000 per person in the town. If this has to be done throughout the whole UK I dread to think what the cost will be. And of course this will have to be paid for by tax payers and electricity consumers. All unnecessary.
Doubling the electrical supply is not going to handle NetZero at all – that electrical supply is just for the new houses and any talk of handling NetZero is just political bullsh!t.
Where exactly is this idyllic Med climate in Großdeutschland? Athens, or maybe Split? I take it that Germany extends to wherever the ECB holds sway?
Let’s face it – the maths doesn’t, and never will, stack up. We’d need to increase our generation capacity by at least 150% (and that’s actual output, not theoretical capacity!) with a corresponding increase in grid capacity as well. Considering that the UK produces (from all sources) only around 1% of world CO2, you’d think someone would have the sense to say that gas does some things better and should be left to do it.
It’s the “all or nothing” approach of those who espouse net zero that irritates me. They are incapable of thinking along the lines of a balanced approach which would reduce the CO2 emissions they so fear. In any event, our puny efforts are like urinating into a gale when you consider the rate of increase of CO2 production elsewhere in the world.
You’re right. The left can’t balance anything, a budget, equation, argument, etc. And they are cracking their whips to implement their wild fantasy of a green future. Will people get tired of the flogging while they still have some power to resist?
“like urinating into a gale”… same kind of messy result.
Not if you do it down-wind.
And the ladies wouldn’t necessarily have that problem.
Could be worse…
Lots and lots of assumptions in the article! Quite obvious that the writer does not have a heat pump. Then there are the regional and country differences in the operation of a heat pump.
Here in northern Florida, I have a 20 SEER heat pump and couldn’t be happier with both it’s operation and the price of the electrical service, especially compared to the ancient heat pump that it replaced. It generally runs 9-10 months of the year and 24/7 during that time as it is used for both heating & cooling. When used, there are no open doors or windows ever!
I have found with the new heat pump to simply set one temperature for operation both day & night to be more cost effective than the constant changing during different periods of the day or night. One gets used to that type of comfort. Is it for everyone? NO, and I don’t assume that others should follow what I like.
Depending on the latitude of the area one is in, a heat pump can be very cost effective compared to other forms of temperature control.
The key phrase in your comment is: “Depending on the latitude of the area one is in, a heat pump can be very cost effective”.
Heat pumps are a niche technology, very useful when appropriately chosen with due consideration for all factors, including but not only latitude, affecting its use in the particular location, but not applicable in many situations.
But, mandating universal use of a niche technology is anti-technological Luddism.
It’s EV mandates for all then.
I live less than a mile south of the 42nd parallel. My home is insulated to meet HP requirements. From January to late March my 20 SEER HP runs over 70% of the time from sunset till a few hours after sunrise. Often, there are nights that the HP runs continuously for hours until outdoor temperature goes below 20 degrees F and it switches to the NG furnace. This even though my HP has electric heater assist in the refrigerant sump.
I also have found that it is more economical to not set back the temperature at night or when not in the home. Worse, when I had the temperature auto setbacks it took well over two hours to raise the temperature just two degrees F. It was still at the night time temperature when I left the house to go to work! At first I set Mon-Fri from 2100 to 1700 as the low setback. Problem was that when I go home at 1830 it still had not returned to the evening temperature. Air blowing from the register was only 5 degrees F warmer than the house and felt like it was even colder than that.
The graphs from my home weather station look like a Roller Coaster! Well over 5 degree F swing. Part of this is caused by the Utility controlled relay for the power for the HP to shut it down on 15 minuet intervals during peak hours – thus the reason it takes forever to warm up the house in the Morning and Evening peak.
Heat Pumps [other than Ground Source] are not ready for prime time.
Anyone at 42-degrees north latitude who chooses a heat pump over a high efficiency natural gas furnace most likely also “thinks” wind and solar can power a modern society and ATM CO2 >300 PPM converts into a demon molecule.
My understanding is that the High Priest of climatology has declared 350ppm the demonising number.
https://www.theguardian.com/environment/2008/jun/23/climatechange.carbonemissions
The safe level is 350ppm!?!? Do they even read their own crap after writing it?
I guess we’re all dead now, as it’s over 420ppm.
Did they ask the plants what they prefer? Oh, ya, 1500ppm, more or less.
I can’t believe people exist who lie for a living – it just makes my guts churn.
I thought being con-artists was punishable by imprisonment but I guess now they give them doctorates in climate science.
“due consideration for all factors,”
Particularly humidity, with an air source heat pump in high RH areas, as the temperature gets to around 2°C, wind chill through the fan/coil allows ice to form on the coil, which rapidly builds up blocking airflow; that ice has to be defrosted either by electrical heaters or hot gas defrost cycle, both methods lose energy to the outside & can reduce the COP (coefficient of performance) from 4-1 down to 1-1, not good in the depths of a cold wet winter !!!
Air Source heat pumps are great in low-humidity areas.
Ground or Water Source are fine for high-humidity areas, BUT £££ $$$
Both are good for background heating, but you’ll still need a booster for hot water.
The UK is a temperate marine climate, with bugger all solar gain in winter, generally not suitable for Air Source heat pumps.
And the defrosting cycle runs once and occasionally twice a day and is not counted in the “Efficiency.” On the days that you get the low visibility fog with sleet, at the freezing point, it will run three times, just like we had the 23rd, 4th, and 5th. I have learned to just switch over to “Emergency Heat” and use my HE NG Furnace.
If you are referring to the Paul Homewood article, it refers specifically to the island of Great Britain. The heat pump variety will typically be air/water and it will be used only in Winter (5 to 6 months) for heating, not Summer cooling.
I will guess your ‘heat pump’ is actually air/air reversible air-conditioning? Florida climate is quite different to that of the British Isles, where the weather is changeable and temperatures fluctuate considerably, particularly night v day in Winter…. below or just above freezing.
Much of the housing stock is 100 years old or more, is brick built, double wall with air cavity with a large loft space. Central heating is usually water fed radiators from a central gas (or maybe oil) fired boiler to provide heating and hot water. Gas is popular because it is the cheapest energy for heating and water.
The amount of energy being replaced by heat pumps when use of domestic gas is phased out, is therefore enormous, plus households will have to install electric water heaters since heat pumps are inadequate for this.
The average cost to replace gas and install heat pumps will be about £14 000 (~$20 000) and it is recommended houses have insulation installed which adds £ thousands to the cost.
Compared to gas, heat pumps in Britain are not cost effective.
“Compared to gas,heat pumps in the UK are not cost effective”
Yep. Current prices of energy in the UK are 7p per kWh for gas and 27p per kWh for electricity, both inclusive of VAT. So the Government wants people to pay almost four times more to heat their house to a lower standard and they are aiming to install 600,000 heat pumps a year from 2028 – insanity!
‘Here in northern Florida…’
An ideal local for heat pumps, since most of your load is probably cooling. You also have the advantage of living in a ‘red’ state, meaning that your regulated utility probably has at least some interest in providing you with reliable, low cost energy.
And no state income tax.
That, too.
“Depending on the latitude of the area one is in…”
I am south of Tampa and had a heat strip installed vs a heat pump. The ROI on the heat pump was 15 years out since I rarely use any heat. Plus, as I mentioned on a post a couple of days ago, it only took a couple of minutes with the heat strip to raise my inside temp 6-8 degrees to get comfortable. I will also add I have low-e energy efficient windows.
Not to mention AI which will increase demand by 20%
Wow..terribly misinformed on both heat pump and grid (distribution, transmission) impact.
Averaging kWh’s is a mistake.
The daily, hourly, seasonal demand peaks will drive the effects of heat pumps on the grid systems.
A heat pump in heating mode adds resistance heat as the compressors cannot keep up as temperatures fall. My heat pump in Pennsylvania has a 10 kW resistance element.
A load flow study on 5.500 kW water heaters showed a 5.500kW on the residential electric meter as expected. On a five house service transformer the impact was 2.7 kW and at the transmission level it was 0.4 kW. This shows that normal water heating demand follows water demand..a widely variable use.
But heat pumps will all add electric resistance as weather temperatures get lower.
I would expect the demand at every point on the system would be closer to 10 kW per heat pump on most winter days.
Much higher resistance elements are needed are needed for houses and commercial buildings, especially ones that are older and not well insulated.
I’m sure that current distribution and grid planners can offer more and better information.
As someone who dealt with customers adding electric heat in barely insulated houses or even using portable electric heaters–their bills were astronomical…the “electrification” idea is terrible.
At the distribution and supply levels it is a disastrous, stupid mistake.
The electric heating coils in an air source heat pump only come on during extended low outside temperatures usually below ~35°F. Here in northern Florida, we might get a week, or two, of those frigid temperatures for the entire Winter. The electric heating coils seldom are used. That is completely different in Pennsylvania where those temperatures are the norm for months.
Another item to keep in mind is that the energy sources are not the same everywhere you go. Here in northern Florida, only electricity is provided to each house. If you want gas, that is propane and you have to get a tank for storage at additional cost.
When operating at ~35°F it would be interesting to see how much time your unit spends in the defrost cycle, especially on high humidity, rainy days. It might be a good idea to check the efficiency of the unit versus outside temperature.
While some units will still work at lower outside temperatures, they can spend more time in the defrost cycle, i.e. pumping heat from the house to the outside coil, than in pumping heat into the house. The efficiency of my unit goes negative at around 40°F where it starts taking more electricity to extract the heat from the outside air that it does to use the electric heating coils.
Salute!
Yeah, Joe, at about 31 deg N lat in “northern” Florida, our first residence was heat pump for summer and winter. Once settled in permanent home , we had natural gas for our HVAC. Most communities in the Panhandle have gas at the residence, so only “country” folks need bottled gas ( like our fishing cabin).
I saw the dramatic increase in electric current many times at the numbers you mentioned…below 40 deg F, you are using electrical (resistive) strips for heat. In summer, the heat pumps seemed about same as the older HVAC systems using air-to-air heat exchangers when both have trouble once the temp is much above 95 deg or even 90 deg F. The large units for commercial buildings and even churches and schools have water spraying towers to help cool the refrigerant, but not homes.
I saw one super heat pump system, cause the guy next door had a heat pump that used ground water down about 40 feet and coils from his unit versus the 90 deg outside air. So you can imagine how efficient his cooling was with a 55 deg heat sink. And ditto in winter when temp got below 40 deg. Additionally, his pump was in the garage, so we heard no noise as with the folks using conventional air-to-air heat sinks.
So let’s see what the greenies do when a) their system becomes expensive and b) when the volts and amps stop due to inadequate power grids.
Gums sends…
Hey Gums, me Mum’s house has an open water source which uses a heat pump for heating and just a water coil for cooling.
She is on Cape Cod, so cooling is mostly de humidifying.
The heating is very efficient but Mass. power is expensive.
Yeah, Drake.
Down here on Gulf coast some folks have their heat exchanging coils out in the bayou. Works great, especially winter as our brackish water hardly ever gets down below 50 deg F, only top 1/4 inch only freezes once in a blue moon.
However, many local communities have not allowed the heat exchanging stuff in a local, small pond/lake.
Nevertheless, using what’s available is a good way to go. I assume folks in Iceland use geothermal systems to exploit the hot magma.
Gums sends…
For the government to mandate 600,000 units installed annually without also mandating the installation the installation of 13GW additional Grid Capacity is pure folly on the part of government
No, not folly, total and complete incompetence, failure to listen to Engineers, and abject idiocy. But what else should one ever expect from politicians?
Well, they also want you to spend 10 of thousands on insulation or tear your house down and live in the equivalent of a modern insulated ice chest. Of course most of the people advocating this stuff are faux intellectuals with a strong command and control Marxist gene.
That explains the Faux Science behind the scam
Heat pumps don’t work when the temperature falls below 25F, then it’s the backup electric heating coils. These are much more costly to run than a natural gas furnace. They also require a 44kW commercial-size backup generator instead of a 22kW home-size backup generator.
We have a heat-pump water heater. Poor performance, often the water is only warm instead of hot. We could have installed a propane water heater for about $2,000 more than the heat-pump water heater. Should have spent the extra $2,000.
Who the hell needs heat when the temperature is 24C?
I read “25F”
Ah yes, reminds me of that global boiling when one spot of water reached 100F.
Well according to the UK Met Office just ONE snowflake falling anywhere in the UK on Christmas Day makes that a white Christmas!
And falling you’ll note, not settling.
Way worse than that.
A heat pump has a Coefficient of Performance that starts at around 3 at mild temperatures and decreases to around 2 below freezing decreasing as the temperature falls. Lower Freon pressures at lower temperatures also decreases the amount of heat that can be moved from out to in. Lower COP + less access to outside heat = eventual use of auxiliary heat, COP=1.0. So right when the temperatures are coldest the heat pump becomes useless.
Wait! There’s more! If you try to conserve heat by turning down or turning off the thermostat another bad thing (for the power company) happens. When the inside temperature is more that 2 degrees below the set point the thermostat calls for auxiliary heat (1.0 COP) on the assumption that a heat pump running at reduced output can’t make enough heat to return the house to the normal temperature. So instead of reducing electricity demand it’s time shifted and compressed in time as everyone gets ready for work and needs the house warm in 15 minutes. That’s not to mention the spike in demand for hot water.
Note to the power utility providing electricity to a lot of heat pumps: Don’t even think about reducing the voltage! An induction motor (fans, compressors) will run at a more or less constant speed no matter the voltage. With a constant speed the load on the motor won’t change as a result of lower voltage so the motor adjusts its operating point to run at the same power, increasing the current. This is a downward spiral for the power company. Not to mention auxiliary heat that has to run more to maintain a heat load that depends on the outside temperature.
A few years ago I noticed our refrigerator not being able to start, It kept cycling making a clicking noise each time. A quick check and the voltage was 106 volts. My call to the utility was succinct, “get the voltage back to 120 or you get to buy a refrigerator!’ The voltage was back to normal within the hour. Normally they are not that responsive.
When the built my home in 2015, I installed a heat pump with mini splits in the Seattle WA area. I can say this is the most efficient heating and cooling source I have had in homes here by a very wide margin. I also installed a tankless gas water heater. My electric and gas bills are the envy of this region.
If nut zero is the objective, then this would be the direction for most new homes to save on energy bills and also future CO2 emissions.
Seattle, WA, has mild weather, even in winter, so heat pumps are the way to go in an energy efficient house.
That is far from the case in New England, and other cold, northern states, with -25 F weather in winter.
Heat pumps enrich the utility and impoverish the user.
I have three heat pumps, already for three years. See my below comment
Sounds like a Goldilocks location. Yes they work in Seattle, but how about Manitoba, or Minneapolis?
HEAT PUMPS ARE MONEY LOSERS IN MY VERMONT HOUSE, AS THEY ARE IN ALMOST ALL NEW ENGLAND HOUSES
https://www.windtaskforce.org/profiles/blogs/heat-pumps-are-money-losers-in-my-vermont-house-as-they-are-in
EXCERPT
My Experience with HPs in my Well-Insulated, Well-Sealed House
I installed three heat pumps by Mitsubishi, rated 24,000 Btu/h at 47F, Model MXZ-2C24NAHZ2, each with 2 heads, each with remote control; 2 in the living room, 1 in the kitchen, and 1 in each of 3 bedrooms.
The HPs have DC variable-speed, motor-driven compressors and fans, which improves the efficiency of low-temperature operation.
The HPs last about 15 years.
Turnkey capital cost was $24,000, less $2,400 subsidy from GMP
http://www.windtaskforce.org/profiles/blogs/vermont-co2-reduction-of-HPs-is-based-on-misrepresentations
My Well-Sealed, Well-Insulated House
The HPs are used for heating and cooling my 35-y-old, 3,600 sq ft, well-sealed/well-insulated house.
The basement, 1,200 sq ft, has a near-steady temperature throughout the year, because it has 2” of blueboard, R-10, on the outside of the concrete foundation and under the basement slab, which has saved me many thousands of space heating dollars over the 35 years.
I do not operate my HPs below 10F to 15F (depending on sun and wind conditions), because all HPs would become increasingly less efficient with decreasing outdoor temperatures.
The HP operating cost per hour would become greater than of my efficient propane furnace. See table 3
High Electricity Prices
Vermont forcing, with subsidies and/or GWSA mandates, the build-outs of expensive RE electricity systems, such as wind, solar, batteries, etc., would be counter-productive, because it would:
1) Increase already-high electric rates and
2) Worsen the already-poor economics of HPs (and of EVs)!!
https://www.windtaskforce.org/profiles/blogs/high-costs-of-wind-solar-and-battery-systems
My Energy Cost Reduction is Minimal
– HP electricity consumption was from my electric bills, and an HP system electric meter.
– Vermont electricity prices, including taxes, fees and surcharges, are assumed at 20 c/kWh.
– My HPs provide space heat to 2,300 sq ft, about the same area as an average Vermont house
– Two small propane heaters (electricity not required) provide space heat to my 1,300 sq ft basement
– I operate my HPs at temperatures of 10 to 15F and greater (depending on wind and sun conditions)
– I operate my traditional propane system at temperatures of 10f to 15F and less
– My average HP coefficient of performance, COP, was 2.64
– My HPs required 2,489 kWh to replace 35% of my fossil Btus.
– My HPs would require 8,997 kWh, to replace 100% of my fossil Btus.
https://afdc.energy.gov/files/u/publication/fuel_comparison_chart.pdf
https://www.nature.com/articles/s41597-019-0199-y
https://acrpc.org/wp-content/uploads/2021/04/HeatPumps-ACRPC-5_20.pdf
Before HPs: I used 100 gal for domestic hot water + 250 gal for 2 stoves in basement + 850 gal for Viessmann furnace, for a total propane of 1,200 gal/y
After HPs: I used 100 gal for DHW + 250 gal for 2 stoves in basement + 550 gal for Viessmann furnace + 2,489 kWh of electricity.
My propane cost reduction for space heating was 850 – 550 = 300 gallon/y, at a cost of $2.339/gal (buyers plan) = $702/y
My displaced fossil Btus was 100 x (1 – 550/850) = 35%, which is better than the Vermont average of 27.6%
My purchased electricity cost increase was 2,489 kWh x 20 c/kWh = $498/y
My energy cost savings due to the HPs were 702 – 498 = $204/y, on an investment of $24,000!!
Amortizing Heat Pumps
Amortizing the 24000 – 2400 = $21,600 turnkey capital cost at 6%/y for 15 years costs about $2,187/y.
This is in addition to the amortizing of my existing propane system. I am losing money.
https://www.myamortizationchart.com
Other Annual Costs
There likely would be annual cleaning of HPs at $200/HP, and parts and labor, as the years go by.
This is in addition to the annual service calls and parts for my existing propane system. I am losing more money.
My Energy Savings of Propane versus HPs
Site Energy Basis: RE folks claim there would be a major energy reduction, due to using HPs. They compare the thermal Btus of 300 gallon of propane x 84,250 Btu/gal = 25,275,000 Btu vs the electrical Btus of 2,489 kWh of electricity x 3,412 Btu/kWh = 8,492,469 Btu. However, that comparison would equate thermal Btus with electrical Btus, which all ethical engineers know is an absolute no-no.
A-to-Z Energy Basis: A proper comparison would be thermal Btus of propane vs thermal Btus fed to power plants, i.e., 25,275,000 Btu vs 23,312,490 Btu, i.e., a minor energy reduction. See table 1A
Thank you for an excellent analysis of what YOU have done and how much it cost you.
Questions: Did you have air conditioning before you installed your heat pumps?
Did you install the heat pumps for the summer COOLING?
Just trying to see the complete picture.
No, we did not have ac.
Thank you for your compliment.
I am an energy systems analyst
Our house is well insulated and well sealed, so it stays cool
We have blinds and curtains
The heat pumps are ON only on the warmest days
Thanks for your response.
Our cabin at 8600 ft has no AC. We open up windows in the evening then close up in the morning when days will be warmer than “average”. I have wished for AC about 5 days in the 18 years we have had the cabin. We are usually there the warmest days of the year around the 4th of July.
I have thought of putting a mini split heat pumps (minor cost from AC to HP) for the MBR and 2nd BR and great room area. I would do the work myself so would not be that expensive, probably $3 to $6 k. Just don’t think it is worth the trouble with the soon to start global freezing cycle.
The range of efficiencies, capacities, source of heat, and so forth are so broad that it isn’t really possible to do much better than plus or minus 20% on electrical demand, installation costs, cost to run and so forth.
I have a NG boiler for my house with a rating of 176,000 BTU/hr and efficiency of 83%, thus, converting to SI units, means that I get a useful heat output of around 42kW. In a cold month, like Dec 2022, I would use 238 Therms of natural gas which is an input of 38,000 BTU per hour. Thus my boiler would seem to operate at a duty cycle (capacity factor) around 21%. I get both heat and domestic hot water from the one boiler, but I doubt I could make a single heat pump do both. Moreover, the typical residential unit is 3 tons which equates to around 10kW — a three ton unit would have to run almost continuously in a month like December, and on the coldest of days which can go to -35F would be unlikely to keep up with demand. My boiler has no trouble doing so because it has a lot more peak capacity.
What about heat source? The highest efficiency ground source heat pump has a COP of 5.3, but this is at a very particular and high ground source temperature, and is a very expensive retail unit cost plus installation. As I would draw heat from my ground source for 9 months a year at a minimum, the ground source heat available within the conduction heat length of my ground heat loop would decline all winter thus declining my COP. I might decline to a COP of 3, and maybe not recover year over year, thus would have a continuously declining COP over a long period.
It is not at all a simple task to size a unit or figure how it might perform relative to the current boiler. My natural gas boiler makes me independent of weather, but the heap pump not so without installing multiple units.
The image of the house- AI or real? Either way, nice image and having rebuilt a few stone walls, I know how much talent it takes to make anything with stone. That house took a lot of time and skill.
It’s typical of rural housing in many parts of UK, our house in Anglesey is similar, built 1806, 3-foot stonefaced rubble walls, no damp-proof course & slate roof.
What is the up-and-down ‘V’ in the raid gutter, or is that an optical illusion?
It’s what happens when the gutter gets a bit wonky. Either a slate has slipped or something has knocked it out of true.
The proponents of these policies appear not to care about the complete lack of feasibility, nor any of the ancillary developments and technologies needed but not planned to give even a modest degree of functionality. This is the epitome of political and bureaucratic incompetence.
We’re making a list and checking it twice. Government bureaucrats, administrators, council members and all the rest will be held accountable.
Don’t forget the “climate emergency” spreading media that is owned by the rich.
Also, don’t forget the politicians who get big campaign contributions from the rich and who control the governments.
The estimates of the costs of stopping warming by 2050 are around $US200 trillion and the rich are planning to make trillions from so-called “climate change.”
So will they continue with a gas supply for cookers or will that be another new electric peak at breakfast, lunch and in the evening as many will be working from home by then?
“…if the government’s target of 600,000 heat pumps a year is met, even within the next ten years, we will be needing at least 13 GW of extra grid capacity, at a time when dispatchable power generation is being shut down.”
And instead of building nuclear power plants, we’re killing whales to power the grid with sunshine, rainbows, and the warm breeze of unicorn farts.
I could tell without reading further that this must be a UK only study, or perhaps Scandinavia.
We here in the states, especially the states with serious winters and hot summers, that there are only a few months of the year when the heat pump isn’t running.
Part of the problem is so many houses are built to minimize outside air flow. Many houses lack windows on on at least one side of the house.
My house has four small windows, smaller than 4 sq. feet for two and less than 2 square feet for the other two, on our Western side.
My southern side has zero windows, 2 small skylights and a sunroom. The sun can be brutal in summer in the sunroom.
Further north just shortens the truly hot part of summer in New England and the Pacific NW.
Further south and the summers start earlier and end later and there are still cold periods during winter.
The Midwest has truly brutal summers and bitter winters. Heat pumps perform poorly, if at all, during very hot and very cold days.
This is a perfectly accurate estimate Paul, excellent article. The FACT that we do not have anything like enough generation is directly connected to the other Elephant in the room, we also do not have anything like enough distribution capacity. The electricity supply system is designed on a principle called “diversity”. This means that the average power used by a single dwelling is taken as about 1kW, or in newer ones a bit more. But the peak consumption by a single dwelling may be many times this, because it is very unlikely that everyone will have the peak at the same time. BUT heat pumps and car chargers both use a higher amount of power continuously, plus the high peak loads like cookers and showers! Loosely speaking, all of the distribution infrastructure, ever cable buried in the road, every transformer, every substation, will need to at least double in size, and actually more than physically double because of the properties of electricity. The cost of this is estimated by National Grid as £3 Trillion for just the Grid, and another probably £5 Trillion for the local cables. It would take a years worth of the worlds cables and raw materials, require a workforce of millions, and more machinery than is manufactured in a year everywhere.
I am certain that everyone can see that this cannot be done, but politicians have been told, yet still destroy our existing infrastructure and promise to build more wind turbines. Elephants and rooms have nothing on this!
Our home has a heat pump for heating and cooling. It has been pretty low-cost to run. Of course we are in South Carolina. It costs more to run it in the winter than in the summer. But not excessively so, except for a couple days last winter when it got down to 6°F on the day before Christmas in 2022. We switched to full electric heat that day and used about 120KWh. Over a whole year, our total electric costs are only $3.22 per day.
Your milage may vary but in Phoenix my peak power bill was August at about 23,000 KWH and my peak heating bill was February at about 13,000 KWH. My minimum bill runs about 800 KWH with an all electric 2,000 square foot house. That is the reason they take the nuclear reactors down in the fall or spring and make sure they are functional for the summer. As the bill is for the previous month, July and August are the hot months with December and January normally the cold months but February can go either way.
In a colder climate, I am sure heat pumps wouldn’t do as well. If the winters were about 10-15 degrees cooler my heat pump would be struggling and my numbers would look worst.