this post was submitted on 12 Mar 2024
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Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world.  About 1C of total warming.  Second chart:  about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability.  Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases.  About 0.5C of cooling with large error bars from SO2.

Recommended actions to cut greenhouse gas emissions in the near future:

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[–] slazer2au 66 points 6 months ago (2 children)

If your concern is lowering a bill:

Where do they work financially? Just about everywhere.

Where do t they work financially? Homes powered by natural gas where the bill is a fixed charge.

If your concern is emissions: they work everywhere.

[–] [email protected] 19 points 6 months ago

The TL;DR hero.

[–] [email protected] 5 points 6 months ago

There are still some edge cases where a grid-powered, air-source heat pump system MAY have slightly higher carbon emissions than a high efficiency furnace RIGHT NOW. This will happen in very cold climates (which means a lower effective seasonal COP) where the grid is very dirty. That might be an argument for not immediately electrifying.

But these systems also ought to last, with proper maintenance, something like a decade. And we should expect there to be no grids dirty enough to make that same calculus happen a decade from now. If you are replacing right now anyway, there's nearly no cases where a heat pump isn't the right choice.

Any if your primary goal is reducing emissions and you can afford it, getting a heat pump system installed in parallel to a traditional furnace (and then only using the furnace on the most brutal days where the COP for the heat pump at its nadir) will still absolutely lower your overall emissions, and probably significantly.

[–] derf82 20 points 6 months ago (1 children)

If a homeowner switches to heat pumps but continues using gas for cooking, they’ll still have to pay the full fee, which can be as high as $34 a month

I wish it were a high of $34. My "Basic Service Charge" is $43.30, and the gas company has proposed increasing it past $50. While they claim it is for infrastructure upgrades, I am sure keeping people on gas is a huge part of it.

And it isn't just cooking. Yes, my range is gas, but so is my hot water heater and clothes dryer. And with 100 amp service, and replacing everything with electricity and canceling gas is a tough ask. And at least I have forced air. People with radiant heat are an even tougher issue

Subsidizing heat pumps with a tax credit isn't enough. We need help making all the needed changes, including service upgrades.

And HVAC companies need to get on board. Technology Connections just released a great video showing (1) that HVAC companies routinely oversize heat pumps because they just grab the capacity of the gas furnace, adding cost and reducing efficiency (as gas furnaces are no less efficient when oversized), and (2) that HVAC companies overprice heat pumps, as they are just air conditioners with a reversing valve that switches which coil is the evaporator and condenser,

My HVAC system here in the midwest is getting long in the tooth and will soon be due for replacement, but with little more than the tax credits, I don't know that I can afford to go heat pump, regardless of the environmental benefits.

[–] [email protected] 9 points 6 months ago (1 children)

In the US, panel upgrades are subsidized by the Inflation Reduction Act too. It won't cover the full cost of getting off gas, but it does make it appreciably cheaper.

[–] derf82 6 points 6 months ago (1 children)

The Inflation Reduction Act is nice and all, but it stops too far short of fixing the issues.

First and foremost, the subsidies are in the form of refundable tax credits, which means you have to have thousands to front until you get your tax refund the following year.

Second, it isn't much. You get a max of $600 for a panel upgrade. They say that can cover up to 30% of the cost, but no panel upgrade is only $2,000. Especially in an older home (where you are apt to find 60 and 100-amp service) that might need extensive wiring work to bring it up to the current NEC. It is likely it will only cover 10%-15% of the cost, which again, only comes as a refund months later.

And it is even less because it has to be combined with other energy improvements, which means you are fronting even more money.

Heat pumps are much the same. Only a $2,000 credit on what is likely a $12,000+ project.

And let's not forget there is also a $600 credit each for stand-alone air conditioning and furnace. So unless a year pump is only $800 more than a new furnace and AC, the tax credit isn't helping much.

If we want people to pick the green option, the green option needs to be the least expensive, not just in the long term, but thanks to boots theory also has to be cheaper in the short term.

[–] [email protected] 6 points 6 months ago (1 children)

The rules let you get the tax credit as a rebate when the upgrade is done, though I don't think that has fully rolled out.

The reality is that in much (though not all) of the country, it's cost-effective to replace a near-end-of-life fossil furnace with a heat pump, since it will lower their ongoing heating bill. People do still need to substitute capital for future fuel payments, and that's a big deal, but it's a lot better than it was.

[–] derf82 2 points 6 months ago

The rules let you get the tax credit as a rebate when the upgrade is done, though I don’t think that has fully rolled out.

That would be nice, but I cannot find a source. Heck, I was checking and it turns out these credits are NONREFUNDABLE, so you can only get a max of what you pay in taxes.

The reality is that in much (though not all) of the country, it’s cost-effective to replace a near-end-of-life fossil furnace with a heat pump, since it will lower their ongoing heating bill. People do still need to substitute capital for future fuel payments, and that’s a big deal, but it’s a lot better than it was.

Eh, sadly, it is a bit fuzzier for many of us.

I just added up the last 12 months of gas bills. Came to about $837. But as I said at the start, $43.30 is a fixed charge. So really I only spent $318 on fuel. Based on my summer bills, I use ~$7/month in gas for cooking, drying, & hot water. So the reality is I only paid less than $250 on heating fuel. Granted, it was a warm winter and those costs will likely go up in time, but still.

At my current electric rate of ~$0.07/Kwh, and assuming that the added use will be at least 1,500 Kwh, that means I save, what, $150/year? That may sound good, but that is a painfully slow playback.

And, again, that is if I can even afford ANY increased cost. Whatever I get, I will have to finance it as it is. Most of us don't have $12,000+ sitting around for HVAC. I want it, and I think heat pumps are great, but not enough is being done to make them the economical choice for those of us in colder cities with a lot of older homes.

[–] taiyang 9 points 6 months ago

I just got a 600 and 2000 credit on a heat pump I bought last year. Funny story, too, because most variable units don't technically qualify. The unit I picked did, but the HVAC people had it on back order and talked me out of it for a slightly older, slightly better variable unit. After a heated back and forth, I talked them into giving me an additional 2000 since (we thought) I wouldn't qualify for the tax credit and I was gonna wait. Fast forward to today, turns out I did qualify and I managed to bumble my way into a discount and a credit.

By the way, if you live in CA, you can see a distribution of what people paid because the Cali credit requires transparency. It's even got a list of the dealers, since they have to give that into when applying for the credit.

Last piece of advice, buy during an off season. HVAC is most in demand in the heat of summer, so doing it in the fall when it won't be useful gives you leverage. The baseline for the 2.5 ton unit was $16k (with non variable 2 tons at $10k) and I got them down to $12k before tax credits and rebates, and that included removing my old gas heater, capping the line, installing vents, revamping my attic, and installing a new sub panel.

[–] ikidd 8 points 6 months ago* (last edited 6 months ago)

I think we'll see heat pumps drop like a stone when its realized they're AC units that cost 1/5th of the price with an extra expansion valve.

What's going on now, between unit cost and insane installation prices, is the wild west.

[–] [email protected] 4 points 6 months ago

Depending on where you live, you may be able to get discounted or free home energy assessments and/or heat pumps.