5 ms·

Even in areas where natural gas is much cheaper than electricity?

icedistilled 4y ago
yes. Because Global warming/climate change is real and installing new furnaces bakes in decades of additional natural gas usage. Also, that natural gas price may change.
- bombcar 4y ago
  If you want to spend the money you can get systems that have heat pump, gas furnace/boiler, and electric. Often used for larger installations that can take advantage of differing prices - and can work best with water heat.
dgacmu 4y ago
A heat pump is likely to have an average efficiency of near 300% - call it 250 if you want to hedge. A high efficiency condensing gas furnace gets about 95%. So on a per-watt-hour basis (equiv., BTUs), your gas must cost less than roughly 1/3 what your electric costs. There are additional savings if your gas furnace is the only gas appliance in your house and you can remove gas service entirely, saving the monthly customer fee.
- pandaman 4y ago
  And to get to 250% COP in heating on average you'd expect to have, at least, 8.5 HSPF2 rating on your heat pump (it's still just the heating performance w/o de-frosting cycles as far as I understand so the real world COP of a 8.5 HSPF2 will be lower than 2.5)
- crgwbr 4y ago
  Unfortunately that is the case in some places. Last year I did the math to see if a ground source heat pump would be feasible (Hudson valley, NY), but even accounting for 400% efficiency vs 95% for gas, gas was still ~30% cheaper per month than electric. And that’s ignoring the extra $50k in equipment cost for the heat pump.
  - chii 4y ago
    > gas was still ~30% cheaper per month than electric this sucks, because gas _should not_ be that much cheaper than electricity, but for subsidies or other market altering shenanigans.
    - tshaddox 4y ago
      Namely externalities. Natural gas is almost certainly more expensive for home heating than electricity, it’s just that a portion of that expense is paid by a large number of third parties.
      - rsj_hn 4y ago
        Seeing as how natural gas is a required input for making synthetic fertilizer, without which billions would starve, it's hard to think of a product with more positive externalities than natural gas. Every time you go to the supermarket, you should be thankful that natural gas allows synthetic fertilizers to feed the world. It's easy to think of negative externalities and ignore positive externalities (or vice versa), but accurately summing these up is very difficult.
        tshaddox 4y ago
        I didn’t say that all natural gas usage has negative externalities. But also, don’t the natural gas costs you’re talking about show up in the price of food?
        rsj_hn 4y ago
        No, because prices are set by supply and demand, not the total social cost/benefit that obtains when all effects, direct and indirect, are taken into account. It is the discrepancy between market equilibria and total social cost/benefit that creates the theory of externalities. But my point is that actually determining social cost/benefit requires very extensive knowledge of all the social benefits and costs provided by something. For example, if you were to ask me what the positive externalities of clean drinking water are, I'd say they are enormous. But I couldn't really give you a number, and if anyone tries to give you a number, they are lying. But that is why I support subsidizing access to clean drinking water, rather than letting the market sort it out. It's just too valuable. When we are talking about things like energy or transportation, they generally have enormous positive externalities, which is why they are historically subsidized. For example, even if you never use a road, you benefit from the stores you buy from having access to roads so that goods can be delivered to them more cheaply. But it's even more subtle, because cheaper transportation means bigger markets. One of the reasons why local businesses historically opposed the construction of roads is that it would force them to compete with other businesses along the same road. If most people had to walk, then they get a captive market. As soon as you introduce roads, prices come down, and quality increases because lots of little monopolies are destroyed. So even if you never leave your house and only shop locally, you are getting huge financial benefits from cheap transportation. Thus there is a positive externality. This is why we don't mind that trucks cause most of the damage to roads but don't "pay their fair share" of road maintenance costs. It's because those trucks create enormous positive externalities by making all the goods we buy much cheaper, even if we ourselves never hire a truck. This is also why many nations subsidize railroads, bridges, roads, etc. The internet also has this aspect of enormous positive externalities. And when you are talking about energy -- it's the basis of modern civilization. Again, if you never use any energy yourself except wood that you chop down, you benefit from all the others who provide you with services having access to energy. Now I'm not saying that natural gas only has positive externalities and that there are no negative externalities. What I'm saying is that no one can tell you what the net is, because these are things foundational to our economy and have profound effects on everything else. So I would not try to use the logic of externalities when talking about these foundational technologies. Externalities makes sense if you are using a lawnmower and it annoys your neighbors, so you let them bid on how much you need to pay them in order to keep using the lawnmower. In very simple models, it makes sense. In the real world, it almost never makes sense, and ends up being a type of economic smokescreen for what is basically politics choosing winners and losers based on arbitrary or cherry picked criteria. So my recommendation is to not try to use "externalities" as a justification. Here's what I would argue, for example, when I am dictator. We want to transition to nuclear power and away from natural gas. So let's tax natural gas and use the money to pay for nuclear power so that it becomes cost competitive with natural gas, and then let's reserve natural gas for things nuclear can't do for us -- such as creating fertilizers. See what I did there? I made my actual motivation the main cause and didn't invoke any economic theory of externalities. Because overall goals should not be slaves to economic models, but rather the economic models should be servants of the overall social goals. The economic model can tell you how much to tax natural gas so that nuclear becomes cost competitive. But whether to decide to switch away from one source to another requires wisdom rather than brute force calculation of all outcomes -- there is no economic model that can spit out the answer. We should not give economists that type of power.
- bityard 4y ago
  I don't have any hard data at hand, but I can say that running my AC (which is just a one-way heat pump) for a few days out of the month in the summer makes my combined gas+electric bill about the same as in the middle of winter when my gas furnace is running all the time.
FriedPickles 4y ago
Id love to see a combined heat and power system that burns natural gas to drive a heat pump compressor, and recovers the combustion heat. I wonder what multiplier it would get on a therm.
- nanomonkey 4y ago
  I've been contemplating the same thing. Something like the WhisperGen stirling engine hot water heater should be available to everyone. Hell even a water cooled honda generator that runs off natural gas, and pumps the radiator fluid into your home for heating purposes would be nice. It seems weird that we aren't producing electricity when ever you burn natural gas for heating.
  - lazide 4y ago
    The issue is maintenance and capital expense due to complexity. Gas furnaces are dead simple, and still break and require maintenance. Heat pumps, more so. Generators? By far the most. Combining the three sounds like a huge headache for marginal efficiency gains.
    - nanomonkey 4y ago
      This is why I started off referencing external combustion engines like Stirling engines. These tend to have very low maintenance needs as the combustion occurs outside of the pistons, so there is no fouling of the moving parts. One could use self lubricating materials like graphite rods as your piston heads and have quite high reliable components. The stirling engines that NASA utilizes are considered maintenance free. As far as efficiency gains, we're talking 25-40% of the energy being produced as electricity and the majority of the rest being turned into hot water for residential use, either by one household or a whole city block. This doesn't sound like a terribly marginal gain. Specially if the energy production is done during the hours when traditional solar installations are not producing which are generally when folks are running their heating.
  - maxerickson 4y ago
    Generators with heat recovery exist, search on micro CHP.

yes. Because Global warming/climate change is real and installing new furnaces bakes in decades of additional natural gas usage. Also, that natural gas price may change.

bombcar 4y ago
If you want to spend the money you can get systems that have heat pump, gas furnace/boiler, and electric. Often used for larger installations that can take advantage of differing prices - and can work best with water heat.

dgacmu 4y ago

A heat pump is likely to have an average efficiency of near 300% - call it 250 if you want to hedge. A high efficiency condensing gas furnace gets about 95%. So on a per-watt-hour basis (equiv., BTUs), your gas must cost less than roughly 1/3 what your electric costs. There are additional savings if your gas furnace is the only gas appliance in your house and you can remove gas service entirely, saving the monthly customer fee.

pandaman 4y ago
And to get to 250% COP in heating on average you'd expect to have, at least, 8.5 HSPF2 rating on your heat pump (it's still just the heating performance w/o de-frosting cycles as far as I understand so the real world COP of a 8.5 HSPF2 will be lower than 2.5)
crgwbr 4y ago
Unfortunately that is the case in some places. Last year I did the math to see if a ground source heat pump would be feasible (Hudson valley, NY), but even accounting for 400% efficiency vs 95% for gas, gas was still ~30% cheaper per month than electric. And that’s ignoring the extra $50k in equipment cost for the heat pump.
- chii 4y ago
  > gas was still ~30% cheaper per month than electric this sucks, because gas _should not_ be that much cheaper than electricity, but for subsidies or other market altering shenanigans.
  - tshaddox 4y ago
    Namely externalities. Natural gas is almost certainly more expensive for home heating than electricity, it’s just that a portion of that expense is paid by a large number of third parties.
    - rsj_hn 4y ago
      Seeing as how natural gas is a required input for making synthetic fertilizer, without which billions would starve, it's hard to think of a product with more positive externalities than natural gas. Every time you go to the supermarket, you should be thankful that natural gas allows synthetic fertilizers to feed the world. It's easy to think of negative externalities and ignore positive externalities (or vice versa), but accurately summing these up is very difficult.
      - tshaddox 4y ago
        I didn’t say that all natural gas usage has negative externalities. But also, don’t the natural gas costs you’re talking about show up in the price of food?
        rsj_hn 4y ago
        No, because prices are set by supply and demand, not the total social cost/benefit that obtains when all effects, direct and indirect, are taken into account. It is the discrepancy between market equilibria and total social cost/benefit that creates the theory of externalities. But my point is that actually determining social cost/benefit requires very extensive knowledge of all the social benefits and costs provided by something. For example, if you were to ask me what the positive externalities of clean drinking water are, I'd say they are enormous. But I couldn't really give you a number, and if anyone tries to give you a number, they are lying. But that is why I support subsidizing access to clean drinking water, rather than letting the market sort it out. It's just too valuable. When we are talking about things like energy or transportation, they generally have enormous positive externalities, which is why they are historically subsidized. For example, even if you never use a road, you benefit from the stores you buy from having access to roads so that goods can be delivered to them more cheaply. But it's even more subtle, because cheaper transportation means bigger markets. One of the reasons why local businesses historically opposed the construction of roads is that it would force them to compete with other businesses along the same road. If most people had to walk, then they get a captive market. As soon as you introduce roads, prices come down, and quality increases because lots of little monopolies are destroyed. So even if you never leave your house and only shop locally, you are getting huge financial benefits from cheap transportation. Thus there is a positive externality. This is why we don't mind that trucks cause most of the damage to roads but don't "pay their fair share" of road maintenance costs. It's because those trucks create enormous positive externalities by making all the goods we buy much cheaper, even if we ourselves never hire a truck. This is also why many nations subsidize railroads, bridges, roads, etc. The internet also has this aspect of enormous positive externalities. And when you are talking about energy -- it's the basis of modern civilization. Again, if you never use any energy yourself except wood that you chop down, you benefit from all the others who provide you with services having access to energy. Now I'm not saying that natural gas only has positive externalities and that there are no negative externalities. What I'm saying is that no one can tell you what the net is, because these are things foundational to our economy and have profound effects on everything else. So I would not try to use the logic of externalities when talking about these foundational technologies. Externalities makes sense if you are using a lawnmower and it annoys your neighbors, so you let them bid on how much you need to pay them in order to keep using the lawnmower. In very simple models, it makes sense. In the real world, it almost never makes sense, and ends up being a type of economic smokescreen for what is basically politics choosing winners and losers based on arbitrary or cherry picked criteria. So my recommendation is to not try to use "externalities" as a justification. Here's what I would argue, for example, when I am dictator. We want to transition to nuclear power and away from natural gas. So let's tax natural gas and use the money to pay for nuclear power so that it becomes cost competitive with natural gas, and then let's reserve natural gas for things nuclear can't do for us -- such as creating fertilizers. See what I did there? I made my actual motivation the main cause and didn't invoke any economic theory of externalities. Because overall goals should not be slaves to economic models, but rather the economic models should be servants of the overall social goals. The economic model can tell you how much to tax natural gas so that nuclear becomes cost competitive. But whether to decide to switch away from one source to another requires wisdom rather than brute force calculation of all outcomes -- there is no economic model that can spit out the answer. We should not give economists that type of power.
bityard 4y ago
I don't have any hard data at hand, but I can say that running my AC (which is just a one-way heat pump) for a few days out of the month in the summer makes my combined gas+electric bill about the same as in the middle of winter when my gas furnace is running all the time.

FriedPickles 4y ago

Id love to see a combined heat and power system that burns natural gas to drive a heat pump compressor, and recovers the combustion heat. I wonder what multiplier it would get on a therm.

nanomonkey 4y ago
I've been contemplating the same thing. Something like the WhisperGen stirling engine hot water heater should be available to everyone. Hell even a water cooled honda generator that runs off natural gas, and pumps the radiator fluid into your home for heating purposes would be nice. It seems weird that we aren't producing electricity when ever you burn natural gas for heating.
- lazide 4y ago
  The issue is maintenance and capital expense due to complexity. Gas furnaces are dead simple, and still break and require maintenance. Heat pumps, more so. Generators? By far the most. Combining the three sounds like a huge headache for marginal efficiency gains.
  - nanomonkey 4y ago
    This is why I started off referencing external combustion engines like Stirling engines. These tend to have very low maintenance needs as the combustion occurs outside of the pistons, so there is no fouling of the moving parts. One could use self lubricating materials like graphite rods as your piston heads and have quite high reliable components. The stirling engines that NASA utilizes are considered maintenance free. As far as efficiency gains, we're talking 25-40% of the energy being produced as electricity and the majority of the rest being turned into hot water for residential use, either by one household or a whole city block. This doesn't sound like a terribly marginal gain. Specially if the energy production is done during the hours when traditional solar installations are not producing which are generally when folks are running their heating.
- maxerickson 4y ago
  Generators with heat recovery exist, search on micro CHP.