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Comment by tommiegannert | Hacker News Reader

Transparency is great, but let's not forget that the point of switching to electricity is to be able to use renewables. We only have one nice planet to live on, and there are others who want to keep being able to live comfortably on it, I've heard. Oil/gas is a potent drug that is difficult to vane off of.

(Arguably solar/battery has the same problem as oil: let's dig and refine stuff from the ground, and not care about how to take care of the concentrated product once we're done with it. But to a much lesser extent.)

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> let's not forget that the point of switching to electricity is to be able to use renewables

Here in the UK, natural gas is used to provide electricity[1], so switching to a heat pump right now isn't likely to help with the environment and (because gas is vastly cheaper per unit energy) nor the utility bill. You might as well spend the capex on the insulation upgrades required for a heat pump anyway, but then stay on gas. The bottleneck seems to be on us weaning ourselves off gas for electricity first.

[1] 53% natural gas during the recent cold snap, and only 16% renewables, according to https://news.sky.com/story/britains-gas-storage-levels-conce...

You get more heat out of using a given quantity of gas to generate electricity which is used to to power a heat pump than you do by burning the gas directly for heat, even when considering generation and transmission losses etc.

Given that even during a time of low output from renewables we still only rely on 53% gas for electricity generation it's still much more beneficial environmentally to use a heat pump.

The monetary cost is another story though, and I agree we do need to work on weaning ourselves off gas.

In areas with moderate outdoor temperatures. Anywhere that the heatpump is going through defrost cycles, that statement is likely false because the COP is likely 1 or less when that starts happening.

Then on the generation side, its worse if the NG generation isn't a modern combined cycle plant. which also tends to nix places with a lot of renewable generation because the NG plants are just peaker gas turbines with much lower efficiency than plants designed for continuous use. So, its all situational, but at the same time if one has the choice for cheap NG using that as a second stage and setting the crossover heatpump temperature at the cost/BTU intersection between the heatpump and NG second stage is a rough approximation of the enviromental costs as well as the actual cost.

> In areas with moderate outdoor temperatures. Anywhere that the heatpump is going through defrost cycles, that statement is likely false because the COP is likely 1 or less when that starts happening.

Modern heat pumps have a COP close to 2 at 5F/-15C while still delivering 50k+ BTUs. Here's one example: https://ashp.neep.org/#!/product/68628/7/25000/95/7500/0///0

While heating, That isn't even a particularly efficient unit (EER 9), and not all all unusual for r410 (which is basically banned for new sales in the USA since jan 1st)

But it has a 150W pan heater, but I don't think that is its primary defrost mode, at least its not going to be at 50k btu at those temperatures unless its also really dry. The pan heater is probably to just assure that the coil melt water doesn't build up in the base pan.

For most of the forced air systemms in the USA, the deforst mode is as I mentioned triggered via outdoor coil temp/runtimes and somewhere below an ambient of ~30F, which will be a coil temp of ~20F. The exact algorithm changes from AC unit to unit, but you get say 20 mins of heating, and then it will flip to 5 mins of AC while not running the oudoor fan, where an electric (or maybe gas) furance will heat the indoor air after it flows over the indoor coil which is cooling the air. So its a double wammy, its taking 5+ mins of operation back at an even higher wattage.

AKA the COP goes negative for 5 minuites... Which will pull the SEER numbers down pretty hard, and that unit actually has pretty poor numbers for being variable speed compressors/etc.(edit: should be SCOP, since SEER(2) is just the ac side, that unit looks to be optimized for heating. Either way, depending on which efficienty spec you pay attention to, the 'problem' tends to be that the SCOP/HSPF/etc numbers are calculated using 'moderate' temp data, so below freezing temps are a minority of the calculation)

I poked around a bit looking for the install/service guide for that unit but didn't find one detailing the defrost algorithm.

Not your parent. We had a Fujitsu AOU15RLS3 installed ~10 years ago. 25.3 SEER apparently, EER 13.9. Also r410A. We mainly got it for AC in summer but we'll take the heating of course. Pretty cold winters here.

    Minimum Outdoor Temperature for Heating: -5°F

Yeah that's about as cold as it's right now actually. During the day!

We'll definitely use the propane fireplace in winter, especially when the power goes out, which has happened more frequently in recent years, as "proper winter" has given way to more freeze / thaw type stuff with ice storms.

Can you elaborate on the statement in the first para? Is it a guess, calculation, or there are real-world data?

A heat pump can be well over 100% efficient based on the energy input for equivalent resistive / chemical heating. E.g. your heat pump could use 100w of electricity to move 400w worth of heat (if generated resistively) from the outside to inside.

There have been multiple studies done that show that current generation heat pumps are quite a bit more efficient for a given volume of gas to burn it in an electrical generation plant and use a heat pump than it is to burn it in the house / building.

I see, but it's still mostly a theory unless we count in all small nuances. Like for a place where winters are really frosty heat-pump usually can't help enough (my own experience), and it seems they come with resistive heating built-in nowadays. Which may change the picture. Also, I'm not a specialist, but my guess is that delivery (or how they call it in the industry) of electricity can be priced in potentially wide range.

Yup, that was all accounted for in what I read (well over a year ago, can't find the link...sorry). It was also for a northern climate country (possibly the UK, maybe Norway, memory is failing me here), so it was not "best case" for heat pumps. They took into account losses from generation, transmission, number of days so cold that it is acting as close to a resistive heater (100-120% efficiency), etc. It was pretty comprehensive.

It was from a "what is the best way to lower our use of fossil fuels" perspective, and acknowledged that switching out all boiler systems for heat pumps would be a high cost, but it wasn't really a study on the economics of it. Just a resource usage perspective.

> Here in the UK, natural gas is used to provide electricity[1], so switching to a heat pump right now isn't likely to help with the environment

Efficiency of a typical combi boiler is 90%. The notional efficiency of a heat pump in UK climate will be around 300-400% (or rather 3-4 COP). Even accounting for transmission losses etc. a heat pump powered from gas turbines is better for the environment than a combi boiler.

And that's assuming the grid doesn't become more green over time. It's not exactly uncommon for cold snaps to be windy too, so it could be 80% renewables. Put it this way, a gas boiler is never going to become more green, a heat pump is going to become more green over it's lifespan (especially in the UK which has very aggressive grid decarbonisation plans).

The incentive structure is broken right now. It costs ~4x to operate a heat pump compared to a gas furnace in California right now. Even with very low use and roof top solar my electric bill is $250 a month when, before heat pump it was $80 with heavier use.

Yes... that's because we're talking about externalities that an electorate wants to go away, but doesn't want to actually pay for.

The entire problem is that we aren't paying the actual cost of what we are consuming, and the cost of a product without these externalities is slightly more, but without making people pay for the externalities, it's not marketable.

This is the tragedy of the commons, and it's only a conundrum because the electorate wants to have their cake and eat it too.

I see this argument a lot that "if only they priced in externalities the numbers would come out in favor of electricity" but I haven't seen a calculation of those externalities that isn't effectively just making up a number.

Like I just picked one from a .edu https://scarab.bates.edu/cgi/viewcontent.cgi and it's just comical with 980% externalities. A number that can be turned into actual policy seems impossible to reach.

It seems like the way forward is just make the thing you want people to do cheaper than the status quo, artificially or not, and let people's economic incentive kick in. But if it's artificial you can't do a California and rug pull net metering.

Climate change is real. The economic impacts are well documented.

https://en.wikipedia.org/wiki/Economic_analysis_of_climate_c...

But the efficiency of a gas power plant is only 20-60%. I'm all for electrification but unless my sums are wonky, a percentage of gas that was used to create electricity for heat pumps would have been better off burnt in a boiler. Over half the UKs power came from gas this last week.

We need to turn back to nuclear until we've figured out grid level storage.

Why not just stay with nuclear, realistically?

Don’t need to reengineer the entire grid then…

Our existing grid won't handle the 150A homes we'll need when everyone has heat pumps and a pair of EVs charging on the driveway.

Storage allows demand-shifting to localities, lessens the burden directly on central stations and stabilises costs. Getting people to buy their own storage also helps but it's hecking costly and much more economical at scale.

DNOs in the UK decline lots of supply fuse upgrades and higher-rate domestic solar installations because local infrastructure capacity issues.

This stuff all needs a bit of an upgrade anyway, but we can defer that if design houses/developments to smooth their own load spikes.

> Here in the UK, natural gas is used to provide electricity[1], so switching to a heat pump right now isn't likely to help with the environment

You can view the live production here:

https://electricityproduction.uk

51% renewables as I write this, and it’s only going to increase over time. I bet the people were arguing about the coal generation until we switched that off.

> because gas is vastly cheaper per unit energy

https://www.ofgem.gov.uk/energy-price-cap

Looking at the prices, and considering heat pumps are 300-400% efficient per kWh it looks like heat pumps may be slightly more expensive, although on a low night tariff it might be closer or cheaper if you consider 8 hours at 7p/kWh.

Great comment, from a carbon perspective it’s even better than 51% .

16% is nuclear, and 19% is imported from France which is about 60% nuclear.

Right now only 10-12% of our electricity is coming from burning gas.

Not to mention the footprint of making something new, disposing the old, and transport.

> Here in the UK, natural gas is used to provide electricity

In the past year, natural gas provided 27.4% of the generated electricity. Wind provided 31.1%. Scroll down on https://grid.iamkate.com and choose "Past year" to see the full breakdown.

>the point of switching to electricity is to be able to use renewables

That argument won't work in practice though. You have to make it make financial sense to each and every individual to encourage them to switch, "Do it because it's the right thing to do" is a tall order when people are already on a tight budget.

I'm sure the new US president will assist in this matter.

> to each and every individual

Not to each one. I'm willing to pay more (within my means and within reason) if it pollutes less and/or produces less CO2.

Given you're surfing this forum, you probably work in tech and have expendable income, most people don't. Also there are many ways you could (and maybe already are) spend money to reduce CO2 impact. Electric car, buying solar, etc.

> that the point of switching to electricity is to be able to use renewables.

You mean using energy sources that have a much better / kwh performance (both in terms of reduction of ecological footprint and price)?

That sounds good and altruistic...

... for the high income techies that make most of the HN audience.

Ask a normal person how they feel about paying for the heat pumps and having an extra hundred or two on their ongoing heating bill and you may get a different answer. Up to and including them not being able to cut expenses anywhere else to compensate for this.

Yes but... the externalities are really expensive, and are going to be paid by somebody. It's a hidden cost

What about in the case of a township offering "natural gas"/methane that would ordinarily be lost to the atmosphere anyway? Isn't it better to burn it rather than leave it as is? Methane is pretty awful stuff in terms of the greenhouse effect.

Agreed, but you only tend to accept that when the other needs in that famous pyramid are taken care of.

Regulation that increases cost of living is only going to cause resentment and we already see where that leads to.

Can't do it with feel good statements, you need the authorities to support/push towards cheaper electricity. Like the Denmark poster said elsewhere on this thread. Is this going to happen globally? I somehow don't think so...

China is pushing hard; EU is pushing less hard but a little; only the US (says) they're going to lag behind these next few years.

America has vast natural gas reserves there's no need to invest.

If your country has to import oil and gas there is a financial reason to change.

You can DIY an usable solar setup, complete with battery, for a couple thousand euros, panels and inverters are already quite cheap and the battery prices is coming down.

If you have the space to put it, you can be self-sufficient for most of the year. Equipment is VAT-free in Germany and Austria, too.

The big problem with solar, is that winter days are cold and dark, so when you need heating the most, it's the least available.

> If you have the space to put it

High income people living in detached houses again...

I think it depends on the country. In some places electricity is cheaper than gas (already) and it starts to go the direction of a no-brainer. But see also https://en.wikipedia.org/wiki/Boots_theory

On the other hand, with less demand from part of the population, gas prices should ultimately start to come down a bit; if we look at straight spot prices and pure economic theory.

However, for some reason utilities don't always care about theory. And we probably want to stop using gas and oil in Europe anyway; would be smarter. (We're pretty much literally paying for wars waged against us; now and in future)

So, I'm thinking maybe some sort of subsidized replacement program; perhaps interest-free loans with government backing or some such; which can be paid back with (part of) the efficiency gains?

Lots of people who are not exactly high income live in the countryside, too..

Additionally, living in shared housing does not disqualify you from having solar panels installed either - if you live in an apartment complex that's a modestly sized 2x2x2 - meaning it has 4x the surface area, and 4x the roof area, the math generally works out the same - for longer houses, it's better, for taller ones its worse, but I think there are a ton of sweet spots, but tall and skinny apartment buildings will lose out.

Exactly that. There was not a single global civilization on Earth that had low per capita energy use. High energy use per capita starts with the price.

It's not only potent, but fantastically cost-effective. There is a reason it's popular, or so I've heard.

It's not so cost effective when you include the future costs.

But like a payday loan, it's hard for most of us to think about those future costs until they're being collected.

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