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Comment by Glench | Hacker News Reader

> The Heat and Building Strategy, to be published alongside the wider net zero review, will include a new 2035 target for a ban on fitting new domestic gas boilers.

Man, I'm glad this is included but the scientific reality is that we need to move much much faster than this.

For reference, even if we perfectly replaced every gas furnace at the end of its functional life starting today with a non-polluting heat pump, we'd still be on track for 2 degrees of warming.

We need gas bans on new houses NOW or at the VERY least create major up-front discounts for heat pumps.

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Good thing the gas price spike has concentrated minds.

My parents live in France. They have to replace their 40 year old gas furnace, and were originally planning on replacing it with a 30% more efficient condensation gas furnace, but the French government gave them subsidies for a heat pump instead. They get heating that is powered by stable French nuclear power and are not exposed to volatile natural gas prices, the French reduce their dependency on gas imports from the distasteful Algerian, Qatari or Russian governments, everyone wins.

That's great that that happened! I think it's to the point now where we need everyone to do that.

Was it hard for them to physically change out their gas system for the heat pump? Was it hard to find installers or units?

It's still work in progress. Finding the installers wasn't hard, but my parents are old and the options are complex, so it took them a while to select the vendor and heat pump.

Right now they are awaiting government approval for their application (it's been very popular and they are swamped, and even had to increase the budget allocation). They also had to do preliminaries like upgrade their electrical connection and add 3-phase wiring in the home, as well as build a concrete platform outside the house to stand the heat pump on.

The heat pump itself should be a drop-in replacement that uses the existing hot water radiators (which means it can't be used as A/C, unfortunately).

Not to get you depressed, but given the amount of momentum involved there is absolutely no way we will meet our climate targets. It's game over on that front, the best you can hope for is damage limitation.

You may be right! But the time for ambition and execution is now because our planet is too damn important for anything less. :)

That I agree with. But the illusion that we're going to get through this unscathed if we all just pull together is at this point in time more harmful than helpful.

I'd add to that that we're already scathed! The higher temperatures have already affected the oceans, wildfires, droughts, and increased intensity for weather patterns like hurricanes.

Why is a ban on gas furnaces so important, when you can burn coal in your stove and oil for heating and both are still very common (at least here in germany)?

I thought gas is way better than coal or oil, because it burns cleaner?

Ah, in the US gas is the most common and I'm not sure about the UK — just going off what the article mentioned.

But yeah, my understanding is that burning gas in your home produces less CO2 than burning coal or oil, but they ALL pollute (and gas often has methane leaks from pipelines which is worse for warming than CO2). Whereas a heat pump emits nothing, is ~3x more efficient than gas combustion, and will increasingly cause no emissions as the grid is powered by renewables.

It's far better to emit NO pollutants in your home (and cars!) than to emit less, especially since polluting home infrastructure is replaced every ~15 years and pollutes for its entire lifetime.

Are all properties suitable for a heat pump though? That's the question. My understanding is they are basically aircon units running in reverse, which means outside heat radiators?

If you can't fit a heat pump, resistive heating should work fine, but it will be more expensive to run. It would obviously put more load on your renewable grid, so you'd want to put heatpumps wherever possible, but at least it's better than burning gas/oil/coal for heat.

> Are all properties suitable for a heat pump though? That's the question.

Generally, yes, but of course it always depends on specific circumstances.

Read up on heat pumps! They're really cool. And yes they're like air conditioning units that can cool and also heat. In addition to heat pump space heating there are also heat pump hot water heaters and heat pump clothes driers and it seems both are more efficient and non-polluting.

It feels magical that they can pull heat from outside in the winter, but that's what they do! The more recent units can even do it in very cold temperatures.

At least in the UK, using coal or oil is very uncommon, while gas is very common.

So gas is the bigger problem to resolve. We need to get rid of them all eventually.

> We need to get rid of them all eventually.

Totally agreed! But for me I'd love to strike the word "eventually" from the sentence. At this point we're in such deep shit that we have to move more quickly than "eventually" in my opinion. :)

It's far better to emit NO pollutants in your home (and cars!) than to emit less, especially since polluting home infrastructure is replaced every ~15 years and pollutes for its entire lifetime.

The UK strategy is to replace those gas burners with heat pumps, which you can power with nuclear energy.

The problem in the UK is that many houses are very old and poorly insulated. Passivhaus basically needs to be the standard (if it isn't already).

Residential coal heating is extremely rare in the US[0], to the point where it occasionally gets a human interest story whenever a reporter runs into someone who uses coal. Most of America uses gas, some newer buildings and the south uses electricity, and wood handily outnumbers coal. The roughest equivalent we have here is oil heating, which is really only common in the northeast. It’s my understanding that that’s being phased out, because it’s unpleasant to live with.

I don’t even know where I’d go to buy coal, to be honest. For most of America the closest we get to the stuff is a charcoal grill.

0 - 130,000 households two years ago, half in Pennsylvania.

"I don’t even know where I’d go to buy coal, to be honest. For most of America the closest we get to the stuff is a charcoal grill."

Well here in germany in winter time, you can buy 10 kg packs in allmost every supermarket. Probably a side effect of the still big ongoing open coal mining. But its gotten quite rare in comparison, when I was a child, it was common for many houses, to have coal in the basement and regular getting a truck for resupply. Now it is mostly for additional heat.

That’s genuinely shocking and horrifying to me. Outside of coal mining areas, it’s viewed as a dirty and inferior fuel here in America. The idea of there being just stacks of the stuff where I buy my food is pretty hard to accept for me.

Outside of a specialist delivery company (“high quality bituminous”, heh), I’d have to travel to a feed & seed store in the nearby farm country to buy coal for heating ($9 for a 40lb bag of anthracite). They’re out of stock, but it’s not clear to me if that’s because of supply chain issues, or because nobody ever actually wants it in my area.

Meanwhile firewood is super easy to get. It’s available everywhere, including in huge stacks outside our grocery stores. I can even buy it from my city at $90 a cord, but it needs to be split.

"it’s viewed as a dirty"

It is. I lived in a small town in a river valley some years ago: you couldn't open the windows in late afternoon, when everyone started to burn their dirty fires.

That's funny, because you get the same thing with firewood and wood furnaces now. Not particularly better on the unhealthiness scale, either.

Actually, between people burning whatever looks wood-like and coal, I'd probably prefer the coal.

You say that, but the EPA has been slowly tightening emission rules for wood burning stoves. Just this year the EPA is beginning to reduce the allowable soot emissions for stoves from 4.5g/h down to 2.0g/h. Old stoves are obviously a problem, but they’re getting measurably better with time.

The model I’m considering purchasing has an actual catalytic converter in it, just like a car, to ensure combustion is as complete as possible.

And cigarette filters are 30% effective at removing solids from inhaled smoke. But you are still smoking!

It's 2021. Burning wood makes no sense from a global warming and certainly not from a public health perspective.

Unless you can wave a magic wand and make alternative sources of energy sufficiently cheaper (or make people sufficiently richer, two sides of the same coin really) people are going to heat with wood where that is economically favorable.

Wood is carbon-neutral. Fossils aren't.

Well, it depends how peope start their fires and what they burn. A clean burning wood fire, started well, is no big problem.

A badly started coal fire? That is bad.

I think in 10 years it’ll be a requirement to have a catalytic converter on every stove.

Here in France, most furnaces are electric, a few use gas, and some stovetops use gas but they are becoming more rare, as it's cheaper to simply not include gas in a building.

It's very surprising to me that people are still burning coal in their home, outside of very rural areas. Same thing with oil (except with cars of course).

From the article being discussed:

"The government is at present drawing up plans to subsidise electric pumps with grants of £5,000 for air source heat pumps and £6,000 for ground source heat pumps."

Yes, that's great! I just wish it was paired with the more ambitious stick of banning new gas hookups.

Right now seems to be a perfect time to announce such large subsidies on heat pump installations. For two reasons:

1. A lot of people in the UK have actually had their savings grow because of covid. Not being able to spend on holidays and going out etc (I realise some have not fared so well).

2. The current crisis in gas.

I think they're going to be swamped with people who want to take advantage of this. I don't think they're going to be able to keep up with the demand. I'm personally going to be on top of it as soon as it becomes available.

That's awesome! Please share with others what you learn in the process!

A further alternative to heat pumps is hydrogen fired boilers. Heat pumps work well in well insulated houses, with large radiators, which aren't attributes of much existing UK housing.

Boiler manufacturers are already designing hydrogen boilers. The question is, how much existing infrastructure can be used to transport hydrogen.

I think we should be able to get to 20% hydrogen at least sooner rather than later, which is being supported by modern boilers.

https://www.worcester-bosch.co.uk/hydrogen

Why do you say heat pumps only work in well insulated houses with large radiators? Heat pumps are ~3x as efficient as the best gas furnaces so why would you need a better insulated house?

Also, the problem with hydrogen is how do you produce it? Probably with renewable energy, right? So why would you waste all that energy converting from renewable electricity to hydrogen then burning hydrogen (which is not super efficient anyway)? Might as well just use the renewables to power your heat pump. Plus, heat pumps already work at scale whereas hydrogen needs a lot more work before it's ready for primetime.

> Why do you say heat pumps only work in well insulated houses with large radiators?

Because heat pumps operate at a lower flow temperature than boilers. Smaller radiators designed to operate at hotter temperatures won't bring your house up to the target heat temperature operating at lower temperatures. They often need replacing. [1]

Trials of heat pumps in existing UK housing have found it difficult giving away heat pumps for free, because of all the extra work required for them to operate properly in the house. [2]

> Heat pumps are ~3x as efficient as the best gas furnaces so why would you need a better insulated house?

Heat pumps in comparison to conventional boilers are meant to be on all the time at a lower temperature, as they take a long time to bring a house up to target temperature.

They depend on good insulation, otherwise the heat never accumulates, similar to if you leave a freezer door ajar, it will never freeze.

> So why would you waste all that energy converting from renewable electricity to hydrogen then burning hydrogen (which is not super efficient anyway)?

At times, renewable energy drives electricity prices negative. We haven't got many ways to store this when it happens, converting water to hydrogen would be a good candidate, which can be delivered using existing gas infrastructure.

> Plus, heat pumps already work at scale

Not in existing UK housing, which would require major changes (insulation, underfloor heating, larger radiators), before they work.

[1] https://www.imsheatpumps.co.uk/blog/can-i-use-radiators-with... [2] https://www.housingtoday.co.uk/news/major-challenges-in-pers...

Yeah, so your argument assumes that retrofitting radiators with heat pumps is the only way to install. Not true! You left out mini-splits which efficiently heat rooms and have the added benefit of being less expensive and disruptive to homes than under-floor heating.

The reality is that we don't have time to wait on unproven technologies like hydrogen boilers (which gas boiler companies are using to try to delay their inevitable demise). We don't have time to wait on an non-existing hydrogen infrastructure. Despite what you say, heat pumps are working at scale today around the world and individuals can go buy them now and successfully heat and cool their homes.

But hey, I'm not a fundamentalist — whatever works! We need all solutions very fast in order to mitigate damage. If part of that is hydrogen then great! It just seems unlikely to scale at the required rate.

> Yeah, so your argument assumes that retrofitting radiators with heat pumps is the only way to install

It's not an argument, I'm just relaying what heat pump installers need to change in order for the pumps to work.

The system also needs to provide hot water.

> The reality is that we don't have time to wait on unproven technologies like hydrogen boilers

They're not unproven, 20pc hydrogen ready boilers are being sold today.

> Despite what you say, heat pumps are working at scale today around the world and individuals can go buy them now and successfully heat and cool their homes.

That some people have used heat pumps to successfully heat their homes was never disputed.

They're just not the panacea they are made out to be for UK housing.

For a poorly insulated house, it's better to fix the insulation than to do lossy and expensive conversion to/from hydrogen, not to mention investment in storage or transport, when at the end of the day the expensive hydrogen will be mostly wasted due to lack of insulation (costing yet more of the expensive hydrogen).

Conversion to hydrogen need not be expensive. In the UK sometimes electricity prices turn negative on very windy days, and hydrogen can be stored.

Pilot schemes are already using hydrogen blend with gas using existing infrastructure. [1]

I've nothing against more insulation, but the UK has a lot of old housing, which isn't always easy to insulate to heat pump standards. In particular areas where the weather is often driving rain, cavity wall insulation can destroy the house. [2]

[1] https://www.energynetworks.org/newsroom/hydrogen-blending-wh... [2] https://www.bbc.co.uk/news/uk-wales-42165358

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