751–760 of 766 posts
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Do you really think it took twenty years to bring them up to speed ? Honestly ? I’m mean if the interest and investment were there innovation would’ve happened sooner ?
Oh yeah absolutely it didn't need to take 20 years.
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Who is your utility? It really shouldn’t be 2-3x much more expensive to operate, but could depend on your rates. Colorado is actually a relatively heat pump friendly climate; it can reach incredibly low temperatures some winter nights, but once the sun is up it’s back to 20-40F. Compare this to months of continuous deep cold near the Great Lakes.
Xcel Energy. I'm usually at $300/month for electricity from November-March. A comparably sized house with an efficient furnace would be $100/month in this area (or so I've been told). My non-heat electric usage works out to something like $50-$75/ month. Our electric rates average 13-14 cents per KWH, but we just moved to timed metering, so that can vary a lot depending on peak hours.
Using these numbers and an average COP of 2.5 (guess) you're at about 6 therms of gas per day, or about $5-6 while the electricity sets you back about $8.
When was your home built? When I was in the northern front range, we averaged maybe 1.5-2 therms of gas per day.
I recently got heat pumps in the hopes that I could phase out my oil furnace. What I can say so far is: The temperature is wildly inconsistent. I don't know if this is a software issue, a hardware issue, or just the way heatpumps work. I've had the installer come back and look at it, I've had the heat pump rep come and look at it too. They basically checked everything and tried to convince me this is normal. With oil…
Also, a thermostat should be away from the air flow from supply registers to measure representative temperature
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Xcel Energy. I'm usually at $300/month for electricity from November-March. A comparably sized house with an efficient furnace would be $100/month in this area (or so I've been told). My non-heat electric usage works out to something like $50-$75/ month. Our electric rates average 13-14 cents per KWH, but we just moved to timed metering, so that can vary a lot depending on peak hours.
Wow, that's nearly 70kWh/day for the entire winter. Most units are only 4-8kW, which suggests your system is running 50-100% of the entire winter. Using these numbers and an average COP of 2.5 (guess) you're at about 6 therms of gas per day, or about $5-6 while the electricity sets you back about $8. When was your home built? When I was in the northern front range, we averaged maybe 1.5-2 therms of gas per day.
But yes, this is another reason I want to move. I’ve done all the insulating I can easily do without tearing everything down and starting again.
70 kWh a day sounds about right. That’s what I calculated for a max load when I was sizing solar systems.
"supercharge the gas-to-electric transition by making it as cheap and easy as possible for their residents to switch." If you really want to make it super easy to switch, design new heat pumps that people can install themselves without having to pay a contractor to install one. Start with window units that look like air conditioners.
Window heat pumps already exist. Ex: https://www.lg.com/us/air-conditioners/lg-lw1216hr-window-ai... or https://www.compactappliance.com/koldfront-12000-btu-heat-co... Mini splits are also fairly easy to install and don’t take up a window.
https://www.canarymedia.com/articles/heat-pumps/renters-you-...
Ones sold in the US won't work below 41F temperature. Two new units that will work at lower temperatures are going to be introduced this year, but will be stupidly expensive.
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I think you are out of touch. You need to compare the PGE rates with SMUD to get the picture. https://www.smud.org/en/Rate-Information/Residential-rates https://www.pge.com/assets/pge/docs/account/rate-plans/resid... (PDF File) PGE's off-peak rates are 3x SMUD's off-peak rates. PGE's peak rates are 1.5x to almost 2x of SMUD's peak rates.
There’s no need to be disrespectful. Just as I need to understand that you have a different rate than I did, vice versa. You’re missing the actual point of my original post
This was your first comment in the thread.
If you don't want the point of your original post to be missed, don't make it cryptic and have surprised pikachu face when multiple people miss your point. We are not attending a stand up comedy here to understand your tone in this text format.
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Right, the heat pump will reduce energy use to maybe 1/3 of a gas furnace, but natural gas is something like 6x cheaper for the same amount of energy, so it is an expensive folly. If California is serious about this, they need to reign in the utilities to reduce prices and or stop the attacks on solar installation.
It's probably academic, but if natural gas is that cheap, then I wonder about more thermodynamically-efficient uses of it. The classic thing is cogeneration. It's a thermodynamic sin to create a large temperature difference (say, furnace combustion chamber vs. house) without running that heat through a heat engine. In the Nordic countries, in parts of Russia, and on some university campuses in the US, that's done wit…
T1 = -9.4 F = -23 C = 250.15 K (Outdoor temperature in winter on cold day.)
T2 = 71.6 F = 22 C = 295.15 K (Indoor room temperature.)
T3 = 2236 K (Adiabatic flame temperature of methane at constant volume.)
Then we have B(T1, T2, T3) = 6.69.
That's very substantial!
Of course, this assumes Carnot efficiencies for everything, so it's an upper bound.
Also, my assumption of T3 being the adiabatic flame temperature may be too optimistic. Google says
> Today's commercial jet engines can reach temperatures as high as 1,700 degrees Celsius (that's 3,092 degrees Fahrenheit)
https://engineering.virginia.edu/news/2018/11/generating-cur....
so letting T3 = 1,700 C = 1973.15 K, we get the slightly lower B(T1, T2, T3) = 6.58.
This is still fantastic.
This is also assuming a very cold day, which is when the system will have lower efficiency. If we instead assume T1 = 0 C = 273.15 K, and use the more conservative T3 = 1973.15 K assumption, then we get B(T1, T2, T3) = 12.4. That's huge.
So, assuming my math/modeling is right, a hypothetical heat-pump furnace could (using Carnot bounds) use around 1/6th - 1/12th the natural gas as a conventional one, even in a very cold place, if you keep all the other properties of the house (insulation, air exchange) constant.
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Essentially: We will only accept climate change action if it’s not degrading our standard of living which is predicated on consuming unsustainably. The end.
Yeah, people should freeze or die of heat stroke. Tell me more about your frictionless spherical world.
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> If California is serious about this, they need to reign in the utilities to reduce prices and or stop the attacks on solar installation. Why do you think electricity prices are high?
A combination of: mismanagement and corruption. To pay for all the people that PGE murdered with their negligence? Why do you think electricity prices are high? Why should the rates be 4x the rest of the country?