OK, so, once again, a total anecdote here. Anecdotes are definitely not a substitute for actual data, there is a sample size of one (possibly zero) involved here, so proceed at your own risk.
During winter in Greenland, it's totally accepted to leave your car engine running at all times. Why? Because it's likely your diesel supply will freeze up otherwise.
The initial rollout of EVs in Greenland was a disaster. Fine during boring season (as summer is known locally: you can't go out and hunt properly!), but useless most of the year: the batteries would just die.
Then, EVs with built-in heat pumps became available, to aid with cabin temperature (mostly) but also very-cold-weather startup performance (coincidentally). These worked pretty well: when parked, the heat pump would supply warm-ish air to the batteries, which would then continue to feed the heat pump, and work with a properly charged power pack the next day.
So, instead of diesel cars idling 24/7, new EVs now run at, say, 80% efficiency in Greenland. Not a huge deal, globally speaking, but still a nice win.
Diesel cars will have a lot of issues from a cold engine way before the diesel freezes outright (diesel sold during the winter typically have freezing points below -40C).
For instance, the battery charges really poorly when it's cold, diesel crystals can form in the diesel filter, even if the fuel is technically liquid, and the engine is really inefficient if it's too cold.
Of these, the battery not charging properly, coupled with a lot more electricity needed to start the engine when cold, is probably the first one you will encounter. If it's -20C, you may have to charge the battery once every few days using an external charger, if you mostly do short to medium trips.
I live in Norway, were we can get quite cold weather too, and the typical remedy is some kind of engine heater, fueled either by electricity or by the car's own fuel (for newer models, mostly).
There are several types of heating elements, some heat the cooliant (heatiant during winter), some heat the engine oil, and some just heat the underside of the car. All can contribute really well to the problems you get down to -40C or a bit below, at least if they provide enough power (some may be underpowered if the car is exposed and it's really cold) I think these will melt crystals forming in the diesel filter, and once the engine is started, diesel will circulate through the engine, ensuring that the fuel in the tank reaches an acceptable temperature sooner. Also, a warmer engine requires a lot less electricity to start, meaning battery issues are less likely.
While I don't think most of these are designed to heat the fuel tank directly, they probably generate enough heat that some of the heating will spill to the fuel, too, especially if the car is sheltered in a garage.
And if the temperature outside falls well below -40C, you can probably heat the garage using a lot less energy than required to keep the engine running.
Keeping the engine running 24/7 in any location where electricity is available, doesn't seem like an efficient solution unless you're deep in Siberia and fuel is subsidized but electricity is not.
How cold does it get then? EVs are good to -35C and most cars should be ok down to -30C. Idling solves nothing about the frozen tires and stiff axles and shock absorbers. Best would be to insulate the car with a simple tarp and I bet -50C wouldn't be a problem.
I live in Saskatchewan Canada these days, and you can see -40C to -50C relatively commonly just about anywhere on the prairies.
I understand -40C isn't that rare in most of BC or Ontario either.
Around the places I've known (not Vancouver. Vancouver is special)
- Diesel gets idled, and starting back up is careful.
- Propane gets idled -35C and below and hopes it won't shut down.
- Gas tends towards long startups but unless it's been left out all day without a block heater, it'll probably be fine.
- Natural gas tends to need idling as per Diesel.
I've no experience with EVs though. But with lack of charging infrastructure throughout most of the Canadian prairies, it might be a while before it's a workable option here.
Keep in mind that with electric the equation is different when you have a home. For most, they can charge it to full each night and have it warm/ready the next day. 110v/15A is enough to keep it from discharging and a warm battery but below freezing a 220/30A or more is better. The install isnt usually that expensive for 30 or 50A if the panel has room too. And in new builds in many places, charge to the car will be required. But always being full each morning changes how we see it, the infra is for those that travel and long trips which are not the norm.
Tangentially related. I remember a YouTube video about life in Siberia where they would build a tarp tent over their cars and build a fire under it to get it moving in the winter
My Toyota auris hybrid battery never kicks in winter. It's a dead weight that makes fuel consumption worse. It helps a bit in the summer. I live in Scotland, so winters are pretty mild.
i'm certain i'm overlooking something, because it's not like cars are generating heat to be reflected by a tarp, unless you mean a driven car, thus warm, covered by a tarp, would maintain its heat longer in -50c ?
The whole worry about EV's an cold weather always seemed to me to be something people unaware of of block heaters would worry about.
Story: One time a friend of mine got a hold of a diesel water heater used for semitrucks. I figured out how to get it running and then he used it a few times to build ghetto hot tubs in the snow.
I'm guessing the price of gas is ridiculous in greenland. Makes sense that an ev would net a quick payoff there. Even if you guys are running your power plants off fossil fuels, the larger generators are probably more efficient.
Diesel is pretty cheap in Greenland, but that's not related to the actual cost of getting the stuff there. One thing to keep in mind, though, is that pretty much nobody has a car in Greenland. Not because of some enviromento-wokism, but just because there are not that many roads.
You live in Ilulissat? Have fun driving between the harbor and the airport (all of the 20-or-so miles). And people do, but they tend to be taxi drivers, and they mostly drive EVs these days, again, not because of the actual cost of the vehicles.
Now, if you want to go anywhere in Greenland, you need a boat. And a sled and some dogs, or, if you insist, a snowmobile.
Sorry if this is a silly question; why isn't there more investment in heated garages? Going outside to get into a below-freezing car sounds very uncomfortable.
If you live in a cold climate, and are looking at heat pumps, make sure you use https://ashp.neep.org/#!/ to look at the low temp BTUs.
The defrost specifications are also worth thinking about. Having your heat turn off for a few minutes to do a defrost cycle can be annoying if you only have one unit.
This thing can be fixed by having low temperature floor heating. It does imply that your heat pump should be air to water or water to water versus a mini-split which is air to air.
Low temperature means only a couple of degrees higher than ambient. It just constantly radiates. That also mean that heat pump needs to work less hard.
It does require a significant amount of insulation to ensure you don't lose the heat immediately.
And because of the high mass it means that interruptions aren't noticed.
If it works great at 10c and OK at 0c and just a little bit at -10c but extracts no useful heat at -20c and your local weather has lots of time below 0c, then no amount of low temp floor heating will help.
This is just plain false. The entire country of Finland (and Sweden, and Norway) installs pretty much only air source heat pumps, air-water heat pumps, or ground source heat pumps in all renovations or new built buildings.
In the north of the country you end up heating your house for some days with resistive heating, but it is still cheaper than any alternative source.
Heat pumps suffer from some issues that I believe can be solved from a policy point's of view.
Heat pumps aren't that powerful. To enjoy it to its fullest you must have a well-insulated house, and ideally low-temperature floor heating.
That way the insulation and floor's volume provide the buffer for when your heat pump is defrosting.
So getting a heat pump without insulation is not smart.
Then there's the cost. A gas heater is 3 times as cheap, and for that price, 3 times as expensive.
Lastly, there's the issue of when it's really cold and the heat pump cannot extract heat from the outside air (this is much less a problem when you have an water to water heat pump, but they are significantly more expensive). Then the thing just runs on electricity. And that can be VERY expensive in certain parts of the worlds.
So we need incentives for insulation first. Then heat pumps. And probably electricity plans that a cold month isn't insanely more expensive.
> Then there's the cost. A gas heater is 3 times as cheap, and for that price, 3 times as expensive.
Only really a thing if there's a local gas network and subsised gas.
> Lastly, there's the issue of when it's really cold and the heat pump cannot extract heat from the outside air (this is much less a problem when you have an water to water heat pump, but they are significantly more expensive). Then the thing just runs on electricity. And that can be VERY expensive in certain parts of the worlds.
They work fine in -25c. Few people in the world live in places that are regularly colder than that for significant chunks of time.
Depends on the rest of your system. Our gas combi outputs 36kw on demand. We use high temperature rads and need no water storage.
To get premium performance from heat pumps you need buffet tanks to heat up water over the day and a low temperature central heating system.
All achievable, but it turns a £10k boiler installation into a £30k house-wide replumb. Well before you factor in actually making the house perform better. It takes a big run up to make the sums work.
> The boiler does not reach 90%+ efficiencies until the return temperatures are around 45°C. This means water must exit the boiler at a maximum of 65°C, impart 20°C of heat to the room via the radiators, and return at 45°C.
edit: and if you read further they suggest that oversized boilers like yours have further efficiency losses:
> When boilers fire up, they automatically ramp up to 70% of their maximum output. For a 21kW boiler (common is most homes) this would be around 15kW. Given that only 6kW is needed on a very cold day, the boiler is always going to overheat the system. When the radiators cannot get rid of enough heat the return temperatures to the boiler are too high for it to condense.
That's fine as long as you're not comparing it to some unattainably perfect fossil fuel based system, and then claiming that the heat pump alternative "needs" big radiators and or whatever when it's been recommended practice to do the same for gas heaters (new install and replacement) for two decades now.
A 2 kW air to air heat pump with a SCOP of 4 is about 2.2 kUSD installed here in Norway (Samsung Nordic Extreme 09 varmepumpe AR09BXFYDWKEE). This is reckoned to be big enough to heat room of 170 m2. Quite a lot of people here have one air to air heat pump on the ground floor and another for the upper floor.
Even down at -30°C it has a heat transfer capacity of 2.5 kW.
You didn't say how much your has heater costs so I have no idea how this compares but it seems reasonably priced to me.
When you say 2.2 kUSD do you mean $2,200.00 or $22,000.00?
In my locale, the installed figure is at or above $22,000 for a heat pump that is about $3,000 for the unit itself. On the other hand, an electric (no heat pump) hot water tank is $900 for the tank and $900 for the install.
I'd really like to have a plumber be able to install a mono block heat pump since the labour costs to install a heat pump look like highway robbery.
Same here, the prices I’ve been quoted for a heat pump are $25-$30,000 Canadian. And the installers will spend the entire meeting trying to talk you out of it and into a natural gas unit.
We need more Europeans to come open businesses here installing these!
You can get 10 heat pumps installed for 22 000 USD here. Maybe more as you'd probably get a discount on the work part of the install if you're doing that many at once.
I think you misunderstand, 2kW is not the heat output of the system, but the energy consumption. That heat pump (AR09BXFYDWKEE) is rated for ~7.1kW of heat output.
What's the limiting parameter here? Obviously heat pumps can be scaled up to arbitrary sizes - I've used unimaginably large ones in the chemical industry. Do you mean power vs cost compared to other options? Power vs volume? Power vs. weight?
Stockholm has a couple 40 megawatt heat pumps as part of a set of just seven heat pumps which provide building heat to an entire district of the city, pumping heat through 3000 kilometers of pipes.
The only limiting factor I'm aware of for most commercially-available home heat pumps is that they tend not to work well below a certain temperature. This minimum temperature can be lowered by increasing the size of the outdoor radiator and adjusting the pump and coolant pressures to match.
Maybe I am wrong, but I thought colder climates already had legal requirements for insulation. Warm climates seem to be the ones with a more lassiez faire attitude. Which is not ideal, but mostly fine? The temperate gradient of 10f to 70f is significantly worse than 90f to 70f.
There are likely code requirements in most colder regions for minimum R-values for ceiling and wall insulation. Of course code isn't retroactive, so there are still a ton of houses with very poor insulation. There are often reimbursements from the government or energy companies for improving insulation as well. Part of the Inflation Reduction Act included tax credits for improving energy efficiency as well.
Those requirements tend to be present for new construction, but old buildings get "grandfathered in" and are exempt. The apartment I currently rent has essentially no insulation. There's the outer (wood) cladding, an air gap, then the lath & plaster inner walls. Single-pane windows. In Buffalo, NY.
How old is that old building? My wooden house in Norway was built in 1952 in a time of relative poverty not long after the war yet it had insulation (wood wool) and double windows from the very beginning.
Their fans also rather noisy. Although you shouldn't be able to hear your neighbors heat pump, I've experienced a rather annoying issue where the fans hit the exact eigenfrequency of the walls, only amplifying the noise inside.
If your house actually has significant eigenfrequencies built in, I would think you could get those issues at many different fan frequencies, or even from other sources of vibration, like a washing machine's dryer program. Or by watching a movie or listening to music.
I would think someone with the right math skills would be able to build something like a base trap to absorb most of the energy in those frequency bands, though.
At this rate governments should ban fossil fuel based heating for new construction and renovations. I see new houses all over the US and Canada still being constructed with natural gas or propane for heating.
That would be dangerous for many rural areas. For some remote regions, blizzards taking out the electrical grid is a real concern. You need a local mechanism to generate heat and an on-site propane/oil tank is the only realistic option.
We're in the process of designing a house in a rural/mountain region and friends and family keep telling us to put in fireplaces/logburners in case the power goes out. But we don't like the idea of all of those particles in the house (plus the external pollution). However we're predicting that we'll have at least one 60kWh+ portable battery parked in the garage, plus solar panels (which aren't great in winter but still help) and possibly a battery like the Powerwall (another 14kWh+). So it feels like the days of worrying about losing electricity are coming to an end.
You can get wood burning stoves that are completely closed as far as the interior of the home goes. All they do is radiate heat where you need it. The hatch where you put in the fuel and the exhaust are all outside (hopefully somewhere accessible if you're in a blizzard :) ).
Daily incident shortwave energy per square meter is significantly lower in the winter (about half of what it is in the summer). You're also not going to get much of a current when the solar panels are buried in snow.
Wood burning stoves are cheap enough and the odds of you losing power to warrant needing one are large enough that it's a safer bet getting one.
You really should follow their advice. Even if you never use it, it'll still help with the resale value of the property. I'd never want to be dependent on the grid that much in the mountains.
>For some remote regions, blizzards taking out the electrical grid is a real concern.
Effectively every fossil fuel powered heater being installed requires electricity for the fans to work.
>You need a local mechanism to generate heat and an on-site propane/oil tank is the only realistic option.
A backup generator that runs on propane. You'd need a backup generator to begin with even for propane heating, so just go full electric with a heat pump.
Eh, most rural folks I know have wood heaters or fireplace inserts, even in the south. If the power is out, they can still manage to keep a room toasty warm and the pipes from freezing. Same with having a gas stove. It's really nice to be able to have a hot meal when the power is out from a hurricane or whatever.
I'm all for electrifying things, but I wouldn't bet my life on them.
Even non-rural areas. See the December 2022 North American winter storm's[1] effects on Buffalo, NY. 11 people froze to death in their homes because power was out for days. Of course a lot of that blame goes to the city government for not having a plan to close the roads well in advance of the blizzard, having no plan to clear the side streets of snow, and thus making it impossible for the power company to service many of the downed lines in residential neighborhoods.
Given the name of the lead author of the paper and the way heat pumps work, I really wish the atricle had worked "Gibb's Free Energy" into the write-up somewhere.
The crossover point in any grid that has significant gas presence - which is absolutely ANY "renewable" grid- is not a COP of 2. It is 3. That is, per this graph, 5 C. A temperature at which if you do things right, process heat (ovens, showers, humans) should be supplying enough of the required delta T that you really don't need to spend a lot with any energy source. And that's the marginal crossover point, not the "I need to remodel my home" crossover point.
Just... what happened to the meanest part of self-criticism that science bodies used to have? Do they think other people won't ask questions? Because I'm sorry, they do so a great deal more now than ever. Many of those "questions" are stupid. But some are not, and shouting them all down means people should distrust you.
Calculations should include not just the CO2 output per kWh of today's grid but also the CO2 output per kWh of the grid over the 20 year expected lifespan of the heat pump. Most developed countries have committed to a net-zero grid by 2035. Even if you believe that they'll break that commitment, they will likely get close.
Comment confused me a little bit (won't heat pump heat be reused too?), until I realized that you were factoring in gas-to-electricity efficiency. That makes sense.
My mum has a heat pump install which she hates for being lukewarm all the time. It feels underspecced!
When I've looked at one for my home to replace a 24kW gas boiler, all I can find is 14kW kits. Am I missing something? Can I not match the output of a big gas boiler?
24kW is basically the peak when it's doing instant hot-water for the taps. You shouldn't need that to heat a home.
You're right, it can't match the _peak_ output, but the whole system is designed so this isn't necessary.
With a "traditional" combi-boiler, it will turn on occasionally to heat the water in the central heating system, and continue to pump it around. When you need hot water, it switches over the heat-exchanger to directly heat the incoming water and this is when it will ramp up and burn the most gas (24kW+).
For an air-to-water heat pump system, the system will be on almost continually, but will heat the water to a lower temperature, the peak power output is less, but it averages out the same. For hot water, the system will heat a storage cylinder.
One of the catches here is that's it not always an easy retrofit as the lower water temperature can necessitate larger radiators.
Might be worth checking how they are using it. If they're used to gas heating in a less well insulated home they may swich it off until they need it, whereas in a well insulated home with a heat pump you want it on basically all the time.
You can, but central units aren’t great right now. Mini-splits are much better. Price is lower, cheaper to install, regulation between rooms is more even, and you can turn off unused rooms to save energy.
Not sure why the market has moved this way but it is what it is. That unit probably is underspeced
Mini-splits are functionally excellent but have a difficult time with the Wife Factor. So far most of the decorative "solutions" are rather poor. I'm sure over time, as they become more popular, people will come up with ideas for how to work them into the home's interior design, but for now, many find them too utilitarian in appearance.
I was looking into this and one factor is that you still need hot water. So with mini-splits your options are either resistive water heating or having a gas boiler as well. I haven’t seen any systems which do mini-splits and also heat a hot water tank.
Up until this past winter basically, natural gas in NorCal was so cheap that you could probably use much more energy and still come out ahead money wise.
One of interesting-if-too-expensive methods I've seen was basically having gas powered heat pumps.
IIRC It was basically using normal gas engine to move the coolant around but it also used heat produced by engine to heat the coils on the cold side so it was getting essentially more than 100% efficiency out of gas.
But it was even more expensive than traditional heat pump.
One of the reasons for natural gas prices increasing is that the compressors that power the system have historically been gas powered, but all federal permits in the last decade or so have required electric compressors, even in remote locations.
And not just new installs, but for existing work/ upgrades.
It's a 2-for, in that price increases and reliability decreases, since the gas grid now requires the (remote) electric grid to work.
Propane is also used in some new fridges and in heat pumps.
I remember some fridge manual where it said minimum room size because they basically did the calculation "if it escapes and room is at least that big, it won't be stoichometric mixture and cause masssive explosion.
I also heard rumours people with old cars that had AC running on freon use it as replacement...
We're well past the point of optimizing for cost unless you're one of those "well it doesn't matter, I'll be dead by then" people who don't care about what's happening to the planet.
If the temperature outside is -20, heat pumps have an efficiency of around 200%. That's nice. But if you feed it electricity from a coal plant running at 33% efficiency, total efficiency becomes 66%, less than many stoves.
That doesn't take into account the transfer loss or the cost of producing an maintaining all that gear.
In places where the vast majority of electricity comes from renewables or nuclear and where the supply is quite stable, heat pumps still make sense in cold weather. But using lignite based power plants to fuel heat pumps in Eastern Europe is something that is attractive more because it lets you heat buildings in highly populated areas while having the air pollution happen far away from population centers.
You put a bigger buffer tank and you heat it over time.
25kw/hr boiler isn't working all the time. That boiler is also often sized to just heat a lot of water for shower/etc so the power is oversized "just" for heating house.
So during normal work the gas boiler will be cycling , while heat pump with lower power is just constantly heating the buffer and then heat from that buffer is used for heating the house.
Having thought about this when I retrofitted a heat pump in my house, I don't see how a buffer helps here.
For a buffer to work, it necessarily needs to be hotter than supply temperature, which means more losses and more work for the heat pump.
Since heat pump can easily adjust the supply temperature, the most efficient system will be the one where the energy delivered to underfloor heating or radiators is just balanced out by heat loss of the building.
Where buffers are useful is heat sources whose power cannot be modulated (my old diesel furnace for example- when it fired, it produced roughly 20kW, with the only adjustment being supply temperature at which it turns off), or where there is a cost to frequent starting/stopping the heat source (I.e. you probably don't want to get up in the middle of night to add wood to a wood-fired furnace, and pellet-fired furnace needs to be maintained more often in such operation mode).
If one really needs 25kW heat source, one really needs a 25kW heat source. There is no clever way around it. The real question is whether one really needs 25kW heat source (which can be answered definitively by either measuring the delivered==required power, looking at the peak continuous fuel consumption (let's say the coldest day or week), or by having accurate heat loss model of the building. In a heating season, the buffer cannot realistically be large enough to significantly reduce the power requirement. For example, 1m3 of hot water when used as a buffer can store roughly 30kWh (when heated 25 degC above supply temperature). My house needed 240kWh of energy in the coldest day, so the buffer would only cover 10% of the needed heat.
I had set up monitoring for my diesel furnace, so I could see for myself what was the peak heat requirement over two heating seasons (10kW continuous in the coldest winter day). So, I selected an 11kW heat pump, which, if needed also has 9kW of resistive backup heaters. It also matched the numbers in energy-efficiency certificate of the house (theoretical calculation based on materials/thickness/local outside temperatures) within 10-15% or so.
> For a buffer to work, it necessarily needs to be hotter than supply temperature, which means more losses and more work for the heat pump.
The buffer is there so the heat pump doesn't have to cycle or throttle but can work with maximum efficiency as long as possible. That is all. It is not there to heat your house for next few hours. I think newer ones that have throttling can just work with hydraulic clutch.
But the biggest difference is that heat pumps really want that more flow with lower temperature situation (as of course efficiency drops with the temperature), so you really want to have either higher area heaters or floor heating.
> Since heat pump can easily adjust the supply temperature, the most efficient system will be the one where the energy delivered to underfloor heating or radiators is just balanced out by heat loss of the building.
That's independent from heat source really. Also if you're using heat pump you need to define efficiency in "how much you pay for power".
If, say you have cheap power at night, it might very well make more financial sense to pump more heat into the system (i.e. heating house a degree or two more) in the night rather than waiting for morning where tariff will make you pay more to do that. Similar if you have solar system.
> If one really needs 25kW heat source, one really needs a 25kW heat source. There is no clever way around it. The real question is whether one really needs 25kW heat source (which can be answered definitively by either measuring the delivered==required power, looking at the peak continuous fuel consumption (let's say the coldest day or week), or by having accurate heat loss model of the building. In a heating season, the buffer cannot realistically be large enough to significantly reduce the power requirement. For example, 1m3 of hot water when used as a buffer can store roughly 30kWh (when heated 25 degC above supply temperature). My house needed 240kWh of energy in the coldest day, so the buffer would only cover 10% of the needed heat.
240kWh is 10kW energy continous. So you wouldn't need 25kW heat pump, you'd need 10kW one working all the time, maybe 12kW if you couldn't tolerate temperature dropping at night by a degree or two. Of course, that's gonna suck if you lower temperature (say going on holiday) then get it back to usual (compared to twice as powerful gas heating) but you can work around that with programming.
The buffer is there mostly to avoid pump from cycling, electric engines like to spin at constant speed instead of being started and stopped every 10 minutes. Also your entire house is a heat buffer too.
Gas boilers are also very often oversized, especially in older homes where someone might've put some isolation in but not tweaked the boiler size for it. Or if you have dual-purpose one that is extra powerful for heating. Less of a problem now as a lot of them can modulate heat output but still.
And actually the condensing gas boilers also like low water temperature on return because the condensation is more efficient.
energy-wise the best solution would probably be gas-engine heat pump (basically heat pump gas engine instead of electric one + piping to also recover heat from that gas motor), but last time I've checked that's pricy for home scale and more maintenance compared to just electric powered one. But you get significantly over 100% efficiency compared to just burning that gas.
Other interesting thing I saw is so-called "co-generators" where you just have electric generator powering your house (and selling excess to the network) + use the waste heat for heating but that looks like a bit hard to balance between too much power and too little heat.
Ground loop heat pumps offer a COP of 3 to 5. If I were to start from scratch, I'd have a diesel/gas powered generator for backups, and if possible, use the exhaust heat to help increase the COP even higher. Even with the inefficiency of the generator, you'd likely get more than twice the heating out of such a system than just burning the fuel directly.
Are they taking into account the side benefit of fossil fuels? The more you use them, the less you need to worry about the cold in the future. It's like a two birds with one stone thing.
I don't see any actual comparison to fossil fuels. They use a measure, COP, which is coefficient of performance, which doesn't seem applicable to fossil fuel furnaces or if applied there would give those furnaces an enormous COP number.
Anyways, I don't understand the need to draw these types of "total" comparisons. If you have reliable electricity, a heat pump is probably great, if you don't, then fossil fuels are clearly the way to go.
Using COP is a easy way to compare heat pump efficiency to conventional heating methods. It is a multiple of the amount of heat energy output given the electricity energy used. A fossil fuel boiler is always less than 1 (usually 0.6-0.8) since it is never 100% efficient at converting the fuel energy to heat energy. Your electric space heater has a COP of exactly 1. So when you see the COPs in the 4-6 range, you get a good sense of how much more efficient heat pumps are.
So, this is based on the assumption that electricity coming into the home is 100% efficient and none of the systems inefficiencies in power generation or delivery need to be accounted for, the way they are in fossil fuels?
Right, this measure is more for consumers and does not take into account generation or delivery. It is especially useful when comparing heat pumps to electric resistance heat, which is often the backup heat source. If the COP falls below one, you switch to resistance heat. But this article is saying heat pumps built today can operate well over 1 at very low temps.
The COP for a heat pump drops as the temperature decreases. The climate should have a large impact on the choice of technology. Here in Florida it is a no brainer, everyone has a heat pump for the cool winter days. In Minnesota, it is a non starter.
It depends on what else you have available. If you have natural gas available at your house then a heat pump is probably not the most economical choice. Here in New Hampshire though NG is not available at many homes and a cold weather heat pump ends up being the cheapest option versus heating oil or propane.
BTUs from hydrocarbon gases (and hydrocarbons in general) are phenomenal, and Natural gas is generally more of a waste product from oil extraction than anything, so is dirt cheap. The equipment required to use them (a typical furnace or boiler) is also cheap, low maintenance, well understood, and widely deployed everywhere.
Most cold climates use fossil fuel heating.
Heat pumps aren’t terrible, and are vastly more efficient than resistive heat for heating. If the only energy source is cheap and electric, it’s an easy win.
But for areas already widely using fossil fuel heating (such as Germany), switching to heat pumps will increase electrical demand by at least an order of magnitude - best case - and since peak heating demand tends to happen when it’s winter, better have adequate storage too. Germany also has very expensive electricity, so it will dramatically increase costs unless extensive amounts of insulation are also done, increasing capex.
So, if we look at price, and especially if we include capex, it’s only competitive in niche contexts or if we expect fossil fuel costs to be immediately and rapidly increased 4-5x. Even then, if done widely it will break a lot of things unless there is a lot of grid upgrades too. Increasing capex.
It’s why Germany is struggling to switch off. They’re not the only ones.
The were once the leader in nuclear energy. They really should have kept that lead, and built more nuclear plants and aggressively switched to electric first solutions such as heat pumps, EVs etc.
Instead, they are winding down their nuclear power plants, and increasing their reliance on fossil fuels in the near to mid term, at the very least, which means issues like this will plague them for some time.
No idea why they didn't pursue more energy independence when they had the chance
No new nuclear power plants since 1989. Peak electricity grid contribution by nuclear power plants: ~30%, while oil and natural gas were used for heating (so replacing that with nuclear power means doubling NPP output, roughly). So Germany still would have had to increase its nuclear power plant capacity 6-fold to go all in.
Compared to France (70% from nuclear power, natural gas for heating in only ~1/3 of homes) this hardly looks like leadership.
As for the reasons: There has been a series of events where nuclear reactors weren't properly handled and where politics colluded with the operators to sweep it under the rug. No matter how safe the technology _could_ be, its management was horrendous.
One such example was a "passively safe" reactor that by now is a glowing mess for 40 years already, and will remain so for another 60-80 years before it can be dismantled: https://en.wikipedia.org/wiki/AVR_reactor
Key quote from that Wikipedia article: "The report listed hidden or downplayed events and accidents and described serious concealed problems and wrongdoings. For example, in 1978 operators bypassed reactor shutdown controls to delay an emergency shutdown during an accident for six days."
As long as people argue about the merits of the technology, they miss the German discourse on nuclear power completely.
Groups that would benefit from the shutdown of nuclear funded the Green movement, which then essentially lead to the country shooting itself in the foot.
Nuclear is just not competitive anymore if compared to renewables and storage. I'm not saying that this was the primary reason for Germany for shutting down their plants, but keep in mind that they didn't start construction of new reactors after Chernobyl.
Literally nobody runs storage, not at the required volumes for a North European country. To claim otherwise is just a fucking lie.
Just... what is your plan with this? The reality is, North European countries are now wholly reliant on there not being a cold winter again. If you check three simple things: the number of MW of heating demands, the lithium prices for a MWh, and the god damn ninety-fifth percentile worst weeks for wind+solar at >45 degrees North, to get the number of hours. You can do this, and ask people with money in the game whilst you're at it. The answer is not ambiguous, and it is no where fucking near regardless of what a Twitter bro with 50 MWh in a desert will prat on about. So why. The Fuck. Haven't you?
I'm not sure what you are implying. Cost of nuclear power plant projects have been well documented in the past and there are lots of current projects to look at. The initial investment costs, cost overruns and high interest rate environment just make it very unattractive economically to build nuclear plants with current designs. There was an excellent podcast episode of The Red Line podcast recently going into details of the capex calculations if you are interested: https://www.theredlinepodcast.com/post/episode-102-the-econo....
This is not saying that technological advancements like SMRs can't change the economics to be more favorable, but it's really not the case if you wanted to start building a plant right now.
The direct comment you replied to is pointing out that besides fossil fuels, there is not only no plan, but no other real apparent options in these scenarios. Which are real scenarios and will almost certainly occur.
So either:
1) we’d need to do massive investment right now (on the order of wartime economic reorganization) for renewables, which no one seems interested in. And while plenty of people seem happy to say things are fine but that don’t even come close to penciling out in reality.
2) maybe actually get better at nuclear.
3) have some non-trivial percentage of the population either freeze to death during some “unexpected” winter storm that was entirely predictable, or go back to fossil fuels (if they can) on an emergency basis.
Or, my guess at the most likely outcome;
4) pretend everything is fine until a bunch of people die, then blame those people for their moral failings. Then start panicking.
While I feel like heat pumps have come a long way and have their uses, the article/study grossly misrepresents the advantage that heatpumps have over fossil fuel heaters.
1. Overall efficiency: fossil fuel heaters burn fuels directly and produce heat, whereas heat pumps require electricity to be generated somehow and then for the electricity to be used. If you have a heat pump with a COP of 2, but the electricity comes from a natural gas power plant with efficiency of 40%, then that's an "overall" COP of 0.8, not 2. If you have a natural gas heater with 90% efficiency, that's actually more efficient than the heat pump overall, despite having a lower COP.
2. Price efficiency: similar to the above, electricity is more expensive than gas in most markets. Even if the efficiency is double that of a natural furnace, if electricity costs more than double than gas (per unit of energy), you can't really conclude that "heat pumps triumph over fossil fuels".
If you take these factors into account, heat pumps don't really "triumph over" fossil fuels once you get below around freezing. Things get more complicated when you're optimizing for carbon emissions vs energy/cost alone, or the upfront cost of the fossil fuel heater (to have the option of using fossil fuel, you need a fossil fuel heater which costs money, so you forgo that and only use the heat pump you might come out on top if it doesn't get too cold too often), but it's frustrating seeing articles proclaiming "COP > 1 therefore heatpumps better".
It is not energy free to extract, store, and transport natural gas, and often it is more wasteful than producing electricity (hydro, solar, wind, etc). Plus, presuming that electricity is coming from fossil fuels when they are only a percentage of generation, and virtually the entire world is working to reduce that use every single day as the second part of the process of switching to sustainable energy, is a limited perspective.
In terms of cost, you likely won't save money in many markets, but as long as it does not cost more you are still not behind on that front.
It is also much, much easier to produce electricity at home than extract fossil fuels, and individual energy independence has great value for many people.
> It is not energy free to extract, store, and transport natural gas, and often it is more wasteful than producing electricity (hydro, solar, wind, etc). Plus, presuming that electricity is coming from fossil fuels when they are only a percentage of generation, and virtually the entire world is working to reduce that use every single day as the second part of the process of switching to sustainable energy, is a limited perspective.
1. in some areas you can do worse than natural gas plants, eg. oil/coal power plants
2. Those are all valid points, and I even acknowledge them in my original comment (ie. "Things get more complicated when you're optimizing for carbon emissions vs energy/cost alone"). However my core objection isn't against heat pumps per se, it's that the article uses a simplistic analysis to conclude that heat pumps are better.
>In terms of cost, you likely won't save money in many markets, but as long as it does not cost more you are still not behind on that front.
Source? For last Janurary eia lists residential electricity as 16.11 cents/kwh in the US[1] and $15.28/1000 cf[2]. If you convert that to kwh[3][4], that gets you an effective price of $0.052/kwh for natural gas. Of course prices vary by region and time, but I'm too lazy to do this calculation for every state/region.
I did not want to make the same point as others, but it has already been pointed out that 3-4 COP for heat pumps is the more common range for comparison than 2 COP. I have done the math in my area, which is very expensive for electricity, and it still pencils out without factoring in my reduced costs if I get solar (which yes, does finally pay for itself).
I didn't downvote this, but I will criticize this analysis: it's good to look at factors beyond COP (although 2 is the lower end of the COP that I would expect from a heat pump, not the average that I would expect), but this fails to go all the way and look at the ultimate problem: warming potential. And the warming potential of burning natgas in a home is still way higher than using a heat pump powered by a natgas plant, because methane is an extremely potent greenhouse gas and because our natgas infrastructure is notoriously leaky.
By "Warming potential" I guess you mean "contributes more towards global warming," not "I feel warmer with natgas heat"?
I had a heat pump in an apartment many years ago, and the big down-side to me at the time was that it felt like it was always blowing cold air on me in the winter. I definitely valued the warm feeling I got from natural gas heat! But I suspect that heat pump design has improved a lot in the last 30 years, so I'd be willing to give it another try.
Electricity seems to generally be expensive where the “free market” has enabled private companies to extract wealth, and then reasonable/cheap and reliable where a Goverment entity provides it. I love my 9c cad Goverment power (and that is after the last right leaning government saddled it with 20 billion in additional costs going straight to private companies)
Using heat pumps for hot water also necessitates storage cylinders, vs modern gas boilers which heat on demand and don't need a cylinder. You can argue about the relative efficiency of this vs heating water on demand (depends a lot on how predictable your usage patterns are) but the space requirements, which may imply a need to remodel in an unsatisfactory way even if someone has the square feet to spare, are a real barrier.
During winter in Greenland, it's totally accepted to leave your car engine running at all times. Why? Because it's likely your diesel supply will freeze up otherwise.
The initial rollout of EVs in Greenland was a disaster. Fine during boring season (as summer is known locally: you can't go out and hunt properly!), but useless most of the year: the batteries would just die.
Then, EVs with built-in heat pumps became available, to aid with cabin temperature (mostly) but also very-cold-weather startup performance (coincidentally). These worked pretty well: when parked, the heat pump would supply warm-ish air to the batteries, which would then continue to feed the heat pump, and work with a properly charged power pack the next day.
So, instead of diesel cars idling 24/7, new EVs now run at, say, 80% efficiency in Greenland. Not a huge deal, globally speaking, but still a nice win.