Climate Change

[GKWood]

It's worth mentioning that heat pumps do struggle when it's really cold outside (efficiency drops a lot and it becomes close to resistive heater), and in some places gas is so cheap (as compared to electricity) that heat pump energy costs can be more expensive than using a gas furnace. However, for the large majority of Americans the first point is not an issue (most Americans don't live in MT/NH/... ; TGR might be an exception here) , and the second point can be addressed with subsidies and/or putting a price on carbon.

[k2skier112]

It's worth mentioning that heat pumps do struggle when it's really cold outside (efficiency drops a lot and it becomes close to resistive heater), and in some places gas is so cheap (as compared to electricity) that heat pump energy costs can be more expensive than using a gas furnace. However, for the large majority of Americans the first point is not an issue (most Americans don't live in MT/NH/... ; TGR might be an exception here) , and the second point can be addressed with subsidies and/or putting a price on carbon.

At 40* a HP starts to lose efficiency, at 25* it's less efficient than a furnace. We're on the cusp of a HP, 5 months a year it would be running at less than peak efficiency.
We're close to replacing our gas furnace and AC unit so I've recently researched this
https://www.moncriefair.com/blog/at-...ing-effective/

One thing to keep in mind, it's not homeowners heating with natural gas that's causing the most CO2 output, it's electrical generation plants that are the biggest offenders of burning natural gas. Yes everything makes a difference, but the largest emitters should be the first to change

https://www.epa.gov/ghgemissions/sou...-gas-emissions


PS-$1,000 for a HP vs a furnace is way low, probably closer to 2 or 3k more. We're still leaning toward a HP

[Bunion 2020]

Good stuff here, Thanks G & Shaft for adding to the conversation.

RE: ICE VS EV VS Hydrogen. Like all new industry, vehicle manufacturers will stake out a type of propulsion be it EV or H and we will see what innovation and technology will bring to market, H Fuel Cells see like a great idea.

[WMD]

Most experts I read say that EV's are the answer for light vehicles and even short haul trucks. Green hydrogen (gray and blue are worse than gas) could be a solution for long distance heavy transportation.

Hydrogen is less efficient, as there are energy losses at multiple steps from using electricity to create hydrogen through electrolysis and then converting it back to electricity to power a vehicle. Just using electricity is more efficient.


"Green Hydrogen — Where Is It Useful? Where Is It Not?"

In this episode of our CleanTech Talk podcast interview series, Zach Shahan sits down with Mark Z. Jacobson, professor at Stanford University and co-founder of The Solutions Project, to discuss green hydrogen. ..

Zach’s focus for this episode of CleanTech Talk is everything green hydrogen from the perspective of Mark, one of the world’s top renewable energy scientists. As a hot topic in clean energy circles, Zach was concerned green hydrogen technology might not deserve the hype it’s been getting as a significant sustainable energy solution. They also dabble in the topic of carbon capture and storage (CCS).

Zach and Mark start their discussion on green hydrogen by exploring where it is particularly useful today and where it might be useful in the future. Hydrogen, as Mark explains, is mainly beneficial when talking about long-distance, heavy transport. And, he emphasizes, it is typically only a good solution if it is created by clean renewable energy in the first place. Why long-distance, heavy transport? According to Mark, it is much easier, more energy efficient, and more cost efficient to use conventional batteries in personal electric vehicles. However, there is a crossover point at which carrying around too many batteries means a loss of efficiency due to how heavy they are, indicating the point at which green hydrogen fuel cells become a more sustainable option.

https://cleantechnica.com/2021/01/31...mpression=true

[shaft]

At 40* a HP starts to lose efficiency, at 25* it's less efficient than a furnace. We're on the cusp of a HP, 5 months a year it would be running at less than peak efficiency.
We're close to replacing our gas furnace and AC unit so I've recently researched this
https://www.moncriefair.com/blog/at-...ing-effective/

One thing to keep in mind,

Gonna start with a very loud, THIS IS NOT TRUE! Just in case the casual reader doesn't return.

Hey man, where do you live? There are cold-climate heat pumps, and there are standard ones.

• Standard - built and optimized for FL, or for use with a backup system. Backup will either be gas or electric resistance. Gas sucks because it is a fossil fuel, but is good because it provides higher supply air temperatures.. Electric sucks because you are talking big amperage requirements. Maybe 60-80A just for the backup. These are the ones that lose efficiency at the rate you are talking. $2-3k cost increase vs. AC is higher than I'm seeing. In Norway, where there is no gas, and the electricity is clean, the standard backup heating system is wood.
• Cold climate - built and optimized to run down to low temperatures. If you're talking a central system, these can start to lose efficiency (still ~3x as efficient as gas) around 17F, then stop working at about 4F. Mitsubishi Hyperheat and Bosch IDS are some cold climate heat pumps that I like, but there are many. In most US climates, cold climate heat pumps do not need a backup system
• Cold climate, ductless split systems will operate down to -13F. I'm assuming above you have a central system and are trying to stick with that. Just noting this.

PM me if you wanna talk it through. I'm a mech engineer with a PE in HVAC. I very often help people electrify their homes. I got 30-60m to help anyone on TGR with that. There is so much variation in houses, it can be not always easy. You're right that a cold climate should set you back an extra $2-3k, but will also be super efficient.

FWIW, 25% of homes in the US are all-electric. My conservative in-laws own two, just by happenstance, and one is in a climate that gets pretty cold. Both on heat pumps, not backup.

One thing to keep in mind, it's not homeowners heating with natural gas that's causing the most CO2 output, it's electrical generation plants that are the biggest offenders of burning natural gas. Yes everything makes a difference, but the largest emitters should be the first to change

Super important to include this chart, but I argue it is incorrect. Def a solid source, but the assumptions are all wonky. What are the problems?:

• Lack of leakage in the gas system accounted for. On a 20-yr time-horizon, methane (aka natural gas) is ~84x worse for the environment than CO2. This means a little leakage goes a long way. By my math, this increases the gas pie by about 75%
• Including electricity is confusing. It is important for accounting backwards, and for avoiding 2degC, but not good for planning. The grid gets cleaner, so lifecycle grid emissions factors are critical for equipment selection. Essentially, you care about average grid emissions factor over the 15-yr life of your heating system going through 2036; not what it looked like last year.
• There are places in the US with 100% carbon free electricity, and Norway/Iceland have been there my entire career. Once you get to carbon free electricity, and include methane leakage gas in our buildings accounts for 30% of national emissions

Bottom line, for climate planning it is safe to assume 30-40% of emissions in 2030 will be from gas in buildings unless we do something. The grid is getting cleaner, the buildings are not.

BTW, I'm not an electrification junky. My dream car is a 1969 Firebird with a v8. I'm a mechanical eng, not electrical. If there was a solution within combustion, I would've found it. There isn't. Ditch the gas. Shit is whack.

[WMD]

We've got a Mitsubishi high efficiency mini split heat pump for part of our home in WY, and it is supposedly 100% efficient to 15 degrees or lower. It still works at -13, but it isn't efficient at that temperature. It works great and we love it.

[telefreewasatch]

Been lurkin this thread from inception.
Got nothin to bring to this table cept maintaining a low impact life style.
And complimenting y'all on not only edjumicating a buncha fellow mags, but doing it amicably.
One of few threads where the next post compliments and adds to the last...
Thanks, Jimmy

[Core Shot]

Thx for the info shaft et al.

Have a few split systems and they are awesome.

Even more efficient when you typically end up with more zones than a typical forced air or water. Just heat or cool the rooms you are using.

Anyone with resistance heat should convert. A small office conversion has saved so much money last winter on electric Bill.
Payback in a few years.

And running in dehu mode is awesome when it’s only humid and not raging hot.

[old_newguy]

Great info here on the heat pumps.

We have gas heat, which I’m not going to change right now, but the gas water heater is coming due.

I’ve been lead to believe that I should get an electric heat pump water heater. It would be in the conditioned space. Anyone have good info on that front? We are in IECC zone 4c I think and have pretty cheap electricity.

[The SnowShow]

Some DJ was spouting off yesterday about how much cleaner gas vehicles are running these days and EV are worse for the environment because of the batteries...creation and disposal. Horseshit, right?

[WMD]

Great info here on the heat pumps.

We have gas heat, which I’m not going to change right now, but the gas water heater is coming due.

I’ve been lead to believe that I should get an electric heat pump water heater. It would be in the conditioned space. Anyone have good info on that front? We are in IECC zone 4c I think and have pretty cheap electricity.

We switched out a gas water heater for a Rheem heat pump heater and couldn't be happier. It uses very little energy and refills quickly. We can control it with an app, which is useful when everyone wants to shower at the same time as we switch from heat pump mode to high demand mode.

Bonus - in the summer it pumps some cool air into our house and helps keep it cool. We haven't really noticed it making the house cold in the winter.

The one downside is that it is noisy. Not a problem if not in a main part of the house, but ours is in a utility/recycling closet off the dining room and we hear it. If we are having dinner we just use the app to pause it while we eat.

[uglymoney]

So can I easily pair a newer heat pump/ac with my natural gas furnace?

I ask because my ac is nearing the end of its service life. It gets cold af here in winter and hotter than a pepper sprout in the summer. Geothermal heat pumps are expensive but necessary if you don't have gas back up. Our house is built on blasted limestone so I'm pretty sure vertical geothermal is not an option (though maybe horizontal into the hill behind our house).

Seems like a hybrid system would be worth looking at ie the ac/heat pump plus existing nat gas furnace.

Sent from my SM-G991U1 using Tapatalk

[ex-powderbroker]

Another 2c on heat pumps. I got one a few months ago because quebec will write you a check for ten percent to get one installed. Ours wasn’t cheap at 4600 but it served a wide range of temperatures efficiently (supposedly), maybe down to ten or so.

during our current heat wave (and hottest august in record surpassing 2019 and 18) it has made the house way more livable. like, without one i am not sure what we would have done.

the bills have gone down but we won’t really have an apples to apples comparison until next spring. Electric is already the cheapest in North America but they want to ship more hydro elec to the states for real money.

i don’t think we will exactly recoup the investment soon but it was worth it as a creature comfort in a house with no AC previously.

the only downside is that while it cools and heats about 1k sq ft, that doesn’t circulate too well into the bedrooms.

[uglymoney]

My furnace almost never runs if it is above 40 with solar gain 2×6 walls and R60 attic.

I have 3 new Marvin windows to put in as well which will also help if/when I get them in.

Seems like the payback would be forever or never. But I do like the idea of burning wind (Iowa is almost 60 percent wind now https://www.google.com/amp/s/www.the...eport/%3famp=1) instead of gas.

Taking a look at the list of cold air heat pumps supplied above. Appears Carrier has some options.

[AirheadD8]

So can I easily pair a newer heat pump/ac with my natural gas furnace?

I ask because my ac is nearing the end of its service life. It gets cold af here in winter and hotter than a pepper sprout in the summer. Geothermal heat pumps are expensive but necessary if you don't have gas back up. Our house is built on blasted limestone so I'm pretty sure vertical geothermal is not an option (though maybe horizontal into the hill behind our house).

Seems like a hybrid system would be worth looking at ie the ac/heat pump plus existing nat gas furnace.

Sent from my SM-G991U1 using Tapatalk

Yes , Always good to have options if your furnace goes out as well. You just have to prevent both units from running together in heat mode . The refrigerant coil is downstream of the furnace, hot air blowing across the coil while the heat pump is heating can stress the unit . Your installer should know how to wire it properly .

I would avoid heat pump water heaters , while in the Summer it helps cool your house but in winter it works your heating system more . Any kind of service call can blow what savings you enjoyed . If you get 10yrs out of a water heater you're doing well . Recycling a heat pump water heater requires removing refrigerant before disposal .

[k2skier112]

Some DJ was spouting off yesterday about how much cleaner gas vehicles are running these days and EV are worse for the environment because of the batteries...creation and disposal. Horseshit, right?

sort of, mostly...if you're power grid is burning coal, yes an EV is worse. if your grid is cleaner, no. but mining lithium isn't clean by any means and battery disposal will be a hudge problem when the majority of vehicles become electric, but it will be more of a ground water issue than co2

https://www.livescience.com/electric...vironment.html

[altasnob]

Natural gas monthly charge normally includes some kind of flat hook up fee. This gives people an incentive to have multiple appliances running on natural gas, and a disincentive to start switching appliances to electric.

Might not have a choice much longer as lots of cities have banned natural gas in new construction and requiring everything to be electric.

https://www.seattletimes.com/seattle...-construction/

[adrenalated]

sort of, mostly...if you're power grid is burning coal, yes an EV is worse. if your grid is cleaner, no. but mining lithium isn't clean by any means and battery disposal will be a hudge problem when the majority of vehicles become electric, but it will be more of a ground water issue than co2

https://www.livescience.com/electric...vironment.html

Good summary, but I'll add that there are not that that many places in the US anymore that are powered primarily by coal. And ain't nobody building new coal plants these days
https://www.carbonbrief.org/mapped-h...es-electricity
I clicked through every state, and here are the states where coal is the largest source of power: Indiana, Kentucky, Maryland, Missouri, Nebraska, North Dakota, Ohio, Tennessee, Utah, West Virginia, and Wyoming.
In most of them, gas (or some other form) is a very close second and the overall grid is likely clean enough that EVs have the overall advantage over ICE vehicles. If you're in WY or WV though, your electricity sucks.

Battery disposal is IMO the biggest problem right at the moment, but one that I expect will be solved sooner than later as there are a lot of smart people working on it.

[shaft]

I would avoid heat pump water heaters , while in the Summer it helps cool your house but in winter it works your heating system more . Any kind of service call can blow what savings you enjoyed . If you get 10yrs out of a water heater you're doing well . Recycling a heat pump water heater requires removing refrigerant before disposal .

Curious - rather than arguing - what's your proposed non-fossil-fuel alternative? Electric resistance, tank-type? Even given the additional heating demand in the winter from a heat pump water heater in conditioned space, it would still be 2-3x less expensive to run than the electric resistance unit. Talking $75/mo vs. $30/mo. I'm fine with anything that avoids fossil fuel use, just a significant efficiency difference.

[Ireallyliketoski2]

My golf course better be green when I drive there in my 14 mpg Sprinter van.

With a Protect Our Winters sticker.

[AirheadD8]

I have a geo thermal unit which when running pre heats the 60 gallon indirect water prior to going into my oil fired water heater. The only reason I use oil is my power goes out quite often and I can run my oil boiler off a 5kw generator. I seriously doubt fossil fuels will every go away but am not reluctant to go to other sources. Since going Geo I went from around 1,000 gallons annually to 300 .

Water heater longevity in my area is not good ,10yrs or less . Water treatment is key but they wear out quickly . The recovery capacity is not nearly the same as a tank type electric so spacing out use is a concern.

The energy has to come from somewhere to heat the water .....Winter operation is a shell game . Summer all good Winter not so much , you still have to heat the space that the water heater is in . There are a lot of moving parts to go wrong as well. More materials go into the construction ,electronics, fans , plastic and the compressor has refrigerant and oil.

[WMD]

sort of, mostly...if you're power grid is burning coal, yes an EV is worse. if your grid is cleaner, no. but mining lithium isn't clean by any means and battery disposal will be a hudge problem when the majority of vehicles become electric, but it will be more of a ground water issue than co2

https://www.livescience.com/electric...vironment.html

The data in that article is from 2014, and more recent analyses find that EV's are better even on coal based grids:

The study methodology is innovative and distinguished from other life-cycle analyses’ in additional important ways. It considers lifetime average carbon intensity of fuel and electricity mixes, and accounts for changes in the carbon intensity over vehicle lifetime given present energy policies. It also looks at real-world usage rather than relying on official test values to estimate fuel and electricity consumption; this is especially important in assessing GHG emissions of plug-in hybrid electric vehicles (PHEVs). It uses the most recent data on industrial- scale battery production and considers regional supply chains, which results in significantly lower estimates of GHG emissions from battery production than other studies have found. And it factors in the near-term global warming potential of methane leakage in natural gas and natural gas-derived hydrogen pathways.

“Even for India and China, which are still heavily reliant on coal power, the life-cycle benefits of BEVs are present today,” said Peter Mock, ICCT’s managing director for Europe. Pointing to the importance of the findings to the European Union’s recently proposed changes to its passenger car CO2 emission regulation, he added, “The results highlight the importance of grid decarbonization alongside vehicle electrification. The life-cycle GHG performance of electric cars will improve as grids decarbonize, and regulations that promote electrification are crucial to capturing the future benefits of renewable energy.”

https://theicct.org/sites/default/fi...PR-jul2021.pdf

[WMD]

In case anyone is wondering, yes climate change is making hurricanes stronger:

Evidence continues to mount that human-induced climate change is causing hurricanes to grow stronger and more destructive. Hurricanes are producing heavier rain, their storm surges are riding atop higher sea levels, and in many cases they are lingering longer over land, causing increased flooding and infrastructure destruction.

Facts for Any Story

• The five costliest U.S. Earth-system disasters (including earthquakes, volcanic eruptions, fires, and all kinds of extreme weather, adjusted for inflation) have all been hurricanes, and all five have occurred within the past 15 years: Harvey (2017), Katrina (2005), Sandy (2012), Irma (2017), and Maria (2017).12
• Hurricanes get their energy from ocean heat; the warmer the water is, the stronger a hurricane can get. More than 90% of the excess heat trapped in the climate system due to human-caused global warming has gone into the oceans, providing the added energy driving recent hurricanes’ extreme wind intensities and the increased evaporation that has resulted in associated torrential rainfall.3
• Globally, the last few decades have seen a growing proportion of strong hurricanes and a corresponding shrinking proportion of weak ones. Specifically, from 1975 to 2010, the proportion of Category 4 or 5 hurricanes (the highest wind speeds) increased by 25-30 percent for every 1 degree Celsius increase in global temperature due to human causes, resulting in a near doubling of the proportion of those most intense hurricanes.4
• Both heavy rain and storm surge—water pushed ashore by heavy winds—contribute to flooding, which causes the vast majority of hurricane-related deaths and financial losses. The amount of rain falling in recent hurricanes has increased due to climate change, including in Harvey (by 20 to 38 percent),56 Katrina, Irma, and Maria. 7 Hurricanes are also producing higher storm surges due to sea level rise.8
• Climate-change-related perturbations in atmospheric winds like the jet stream appear to be contributing to a trend in which hurricanes are moving more slowly over the United States9 (slowing by 17% over the past century),10 and are increasingly likely to “stall” near the coast, potentially leading to catastrophic local rainfall and flooding. 1112
• There has been a significant increase in how quickly hurricanes intensify in the Atlantic basin in recent decades, an expected symptom of global warming.13 Hurricanes that intensify rapidly are difficult to forecast accurately and prepare for, especially when this occurs close to the coast, and cause a disproportionate amount of human and financial losses.14
• Globally, hurricanes are reaching their maximum intensities further from the tropics, shifting toward temperate, heavily populated coastal regions that have not historically experienced them. Northern Hemisphere hurricane peak intensities have shifted northward by 100 miles in the past 30 years.15

https://www.sciline.org/climate/hurricanes/

[shaft]

Tahoe or other fire-risk mags, how much have you spent on defensible space? Would be useful for me to make as a comparison to the cost of electrification.

[old goat]

About a million dollars in sweat equity, zero in cash. But it doesn't matter a lot what I do on my 50x100 ft lot, with all the neighbors with 5 ft setbacks and lots of untreated lots and land.
We're about to vote on a $179/yr parcel tax to beef up community wide prevention, including defensible space. So if it passes--that's what I'll be spending.
What does electrification have to do with it?

1/3 of Americans experienced a weather disaster this year.
https://www.washingtonpost.com/clima...hurricane-ida/