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Heat pumps are defying Maine’s winters and oil industry pushback

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Re: Heat pumps are defying Maine’s winters and oil industry pushback

#111

Post by pfdietz »

adql wrote: post #59
flyingfences wrote: post #25

Earlier quoted context omitted.

> The batteries would need to somehow be kept warm though. If I were buying such a setup, I'd just put the batteries in the basement. Plenty of space, and it stays 40-50°ish year-round here.

Not that many homes are built with basements nowadays. Water to water heat pump with pipes being directly under building's basement might've been pretty neat solution tbh, if you're digging for basement anyway might as well put some piping there for the heat pump

(Googles) I didn't realize basements were falling out of favor. Interesting!

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#112

Post by jakedata »

thehappypm wrote: post #98
jakedata wrote: post #84

Heat pump electrical usage does not go up as the temperature drops. In fact the actual heat pump itself uses less electricity because the compressor needs to slow down in order to scavenge the outdoor heat needed to vaporize the refrigerant. What causes a spike in electrical usage is the backup resistive heat source that kicks in when the compressor cannot satisfy the demand for heat. Installing a heat pump that is e…

Incorrect, efficiency drops as the temperature differential grows. This is a basic law of thermodynamics, since you can extract energy from a temperature difference, it must require energy to create one.

Absolutely true - efficiency drops. Electrical consumption also drops if your heat exchanger can't scavenge enough heat from the air to vaporize your refrigerant. The compressor must slow down.

Or as I pointed out - you can activate a backup heat source which causes a huge spike in electrical usage. Probably better than freezing however.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#113

Post by olau »

londons_explore wrote: post #18

I worry about the 'futureproofness' of heat pumps. Specifically, heat pumps use more energy on cold days. They use a massive amount more energy on the coldest days. Today, if you use double the electricity, it costs double the money. Thats affordable as long as it happens rarely. But, with lots of people getting EV's and heat pumps, and the generation mix getting more wind and solar, I forsee energy companies forcing…

You forget that if you could earn 50x the price regularly, then there would be people willing to invest in say batteries, and those people would compete and bring the price down.

Of course, if it only happens rarely, there would not be enough money in it, but then it wouldn't be a problem for the home owners either.

Also note that while electricity is expensive to store, heat storage is actually pretty cheap. It works much better at scale with say a district heating system where you can economically do seasonal storage. But you can do it on an individual level too over shorter time spans.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#114

Post by mkozlows »

losvedir wrote: post #65

I know heat pumps are all the rage on HN these days, but I looked into them for myself in Indiana, and they don't seem to make financial sense at all, unfortunately. My utility, NIPSCO, charges $0.25699/therm for gas. There are 29.3 kWh of energy in 1 therm of gas, and my furnace is 95% efficient, so this works out to an electric equivalent of $0.009/kWh. That's more than an order of magnitude cheaper than the electr…

You have very, very cheap gas. Suspiciously cheap. Are you sure you're factoring everything in? NIPSCO's rate pages show much higher rates: https://www.nipsco.com/bills-and-payments/billing-programs/c...

In Michigan here, it's like $1/therm (doing the conversion from the Mcf they actually bill in).

Multiply your gas numbers by four, divide your electric numbers by three (to reflect a COP of 3 -- that is 300% efficiency -- for a typical heat pump), and your order of magnitude goes away.

If your gas really is that cheap, then yeah, you're still much cheaper with gas, but also you've got a sweetheart deal on gas.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#115

Post by thehappypm »

jakedata wrote: post #112
thehappypm wrote: post #98

Earlier quoted context omitted.

Incorrect, efficiency drops as the temperature differential grows. This is a basic law of thermodynamics, since you can extract energy from a temperature difference, it must require energy to create one.

Absolutely true - efficiency drops. Electrical consumption also drops if your heat exchanger can't scavenge enough heat from the air to vaporize your refrigerant. The compressor must slow down. Or as I pointed out - you can activate a backup heat source which causes a huge spike in electrical usage. Probably better than freezing however.

Most heat pumps don’t have a backup built in anymore, though. I have 2 (LG and Mitsubishi) and neither has a resistive backup built in.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#116

Post by nkurz »

losvedir wrote: post #65

I know heat pumps are all the rage on HN these days, but I looked into them for myself in Indiana, and they don't seem to make financial sense at all, unfortunately. My utility, NIPSCO, charges $0.25699/therm for gas. There are 29.3 kWh of energy in 1 therm of gas, and my furnace is 95% efficient, so this works out to an electric equivalent of $0.009/kWh. That's more than an order of magnitude cheaper than the electr…

Your natural gas price (if correct) is much lower than the national average, and even much lower than your regional average. Average natural gas prices in the US for Dec 22 were $1.67/therm while average electric prices were $.17/kWh. Here's a great chart, with regional values also: https://www.bls.gov/regions/midwest/data/averageenergyprices....

I think you are right though that much of the "hype" is based on avoidance of fossil fuels rather than straight economic advantage. The hope is that eventually the electric grid might be all renewable energy, while the efficiency of burning gas doesn't have much room to go up.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#117

Post by thehappypm »

tootie wrote: post #104
jakedata wrote: post #84

Heat pump electrical usage does not go up as the temperature drops. In fact the actual heat pump itself uses less electricity because the compressor needs to slow down in order to scavenge the outdoor heat needed to vaporize the refrigerant. What causes a spike in electrical usage is the backup resistive heat source that kicks in when the compressor cannot satisfy the demand for heat. Installing a heat pump that is e…

I know all the excitement is around air source pumps, but I'd love to see ground source get cheaper to install. It's nearly impervious to weather conditions. If you live some place that actually gets cold enough to stymie an air pump, then maybe investing in ground source is worth it.

Ground source is losing the war.

Too expensive to install, and if something goes wrong, start digging.

Air source is getting better and better all the time.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#118

Post by cheschire »

pen2l wrote: post #46
flyingfences wrote: post #3

There was a thread [0] on /r/Maine in the aftermath of the extreme cold snap last weekend, when outdoor temps dropped into the negative double digits, where people chimed in on how their heat pumps held up. By and large, they confirmed that the manufacturers' claims are correct -- they do keep working (albeit less efficiently) down to the rated temperatures and in some cases even below. The winning strategy, at least…

In addition to this, I think we should go back to doing things the hard way, the old-school way: adapt and adjust your lifestyle to temperature changes like our ancestors did. Let the temperature dictate your cooking: do the dishes that require oven use, that require you to have 3 stoves on at the same time (and crucially, avoid these dishes in the summer!). Go on a bulk in the winter time so that you are more resili…

Our bodies are able to compensate for extreme cold a lot better than extreme heat, so it's important to recognize that we are going to increasingly need effienct heat management systems that prioritize removing heat in an efficient and scalable way rather than focusing on adding heat. As you say, we can make up the difference ourselves usually by just adding insulating layers to retain core heat.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#119

Post by euroderf »

tootie wrote: post #104
jakedata wrote: post #84

Heat pump electrical usage does not go up as the temperature drops. In fact the actual heat pump itself uses less electricity because the compressor needs to slow down in order to scavenge the outdoor heat needed to vaporize the refrigerant. What causes a spike in electrical usage is the backup resistive heat source that kicks in when the compressor cannot satisfy the demand for heat. Installing a heat pump that is e…

I know all the excitement is around air source pumps, but I'd love to see ground source get cheaper to install. It's nearly impervious to weather conditions. If you live some place that actually gets cold enough to stymie an air pump, then maybe investing in ground source is worth it.

One word: robodiggers.

Re: Heat pumps are defying Maine’s winters and oil industry pushback

#120

Post by olau »

acidburnNSA wrote: post #31
mkozlows wrote: post #19

Earlier quoted context omitted.

It's not that ironic. Electrification isn't a "welp, we're done now, yay" thing, it's one of two parallel paths that works together for decarbonization. 1. Electrify all the things 2. Clean up the electrical supply Obviously if you only look at one of the paths in isolation, it doesn't solve problems ("it's great that everything's electric, but electricity is still high carbon"/"it's great that electricity is clean,…

Why electrify all the things instead of decarbonize all the things? Lots of places use zero carbon nuclear district heating to take advantage of the hot water for building heat. It can be pumped 100 km from the plant as it is at Beznau. This makes nuclear more cost effective as well since you're using a valuable product (heat) that is otherwise wasted.

I think the answer is simply that if you run the numbers, it's just not economical to use nuclear plants for district heating. It's probably great if you can use district heating for cooling, but generally nuclear plants are very expensive so you want to get as much high-valued electricity out of them as possible.
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