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Is it better to heat house with gas or electricity? We have gas insert and gas heating but am looking at other options for sustainable energy use. Thank you!

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    Welcome to Sustainable Living! It depends on the source of the gas and electricity. Can you add to your question where the gas is coming from, and what percentage of the electricity is from renewable sources? If you're unable to find that out, please add the location where you live. – THelper Feb 7 '18 at 8:11
  • @THelper If 90% of electricity in an area are from renewable sources, all users of electricity are guilty of using the rest 10%: sustainability.stackexchange.com/questions/7112/… ...so it doesn't matter what percentage comes from renewable sources. All that matters is whether exactly 100% or less than 100% are produced in a carbon-free manner. Also, you are excluding nuclear for no reason at all. Nuclear is equivalent to renewables in produced emissions. – juhist Feb 20 at 18:28
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If you have access to electricity that comes from renewable sources (sun, wind, hydro, waves, biofuel) or from nuclear, then I would recommend getting a heat pump. Simply said a heat pump takes energy from the outside and puts it on the inside, sort of like a refrigerator, but done the other way around.

Heat pumps lower the electric usage significantly compared to heating with electricity directly, which you don’t really want to do. It can reduce your electric heating bill to a quarter [1]. I have one taking energy from the bedrock with two 100 m deep drilled holes, connected to my water bourne heating system. But you can take energy from the soil or a lake. If you have a heating system that doesn’t have water radiators then you can take the energy from the surrounding air.

[1] https://www.energy.gov/energysaver/heat-and-cool/heat-pump-systems

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    Heat pumps are inefficient in cold climates nordicghp.com/2015/12/air-source-heats-pump-cold-climates – Graham Chiu Mar 12 '18 at 18:14
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    Air heat pumps are slightly less efficient than a heat pump that takes energy from thr soil, bedrock etc. If it is really cold our electric heater kicks in, if it is -15C or so. But that doesn’t negate the fact that it works really well in general. – Thomas Bjelkeman Mar 13 '18 at 22:51
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If you have access to enough green electricity to heat your home (and you will need a lot) then electric will be better. If you're grid connected then almost certainly gas (possibly even wood, especially if you burn oxygen starved and bury the biochar) is better. Consider that increasingly gas is a power source used on the grid, so if you use electricity you're going gas -> heat -> electricity -> heat whereas if you use gas directly that's just gas -> heat, cutting out several steps which introduce efficiency losses.

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Unless you have your own or community biogas reactor then gas is not a renewable resource.

Since the 1970s, China has been promoting the use of underground, individual household scale, anaerobic digesters to process rural organic wastes. There are approximately 5,000,000 households using anaerobic digesters in China. The digesters produce biogas that is used as an energy source by the households, and produce fertilizer that is used in agricultural production.

http://www.cityfarmer.org/biogasPaul.html

Furthermore, you may be paying for both a line charge for gas as well as the line charges for electricity with dual connections.

Heat pumps are also the most efficient way to heat your house in most, but not all climates, and run on electricity.

Ultimately it depends on how the electricity is generated, and if there is a significant component of that power generation from non renewable resources then you may be better off with gas.

  • Why would one need to have their own biogas reactor? Why would't gas from biogas reactor owned by a city / state / country be a renewable resource? – THelper Mar 12 '18 at 7:41
  • Name one city that supplies biogas in the U.S. ... I have no idea of what is available, whereas home biogas is readily done – Graham Chiu Mar 12 '18 at 8:46
  • A quick google search shows me this project which says that '[biogas] will be sent nationwide through the natural gas pipeline system', but admittedly I don't know if the plant is operational yet. In any case, where I live (Europe) there are several biogas plants that inject gas into the grid. – THelper Mar 12 '18 at 9:04
  • I think the closest thing in the U.S. would be farms and sewage treatment plants which convert manure into biogas -- however as far as I know, most of these burn the gas locally to use the heat/electricity for their own needs, occasionally export excess power to the grid. But the gas never leaves the site. – LShaver Mar 12 '18 at 14:34
  • @THelper added a link. Home based biogas reactors are common in some countries. – Graham Chiu Mar 12 '18 at 18:12
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The unfortunate answer right now is that natural gas is the best option for heating. It's less expensive, and not enough of electricity on the grid is produced from renewables... yet. Spend money on other sustainability-related things instead.

To improve sustainability, invest in your own solar cells (and small wind turbine if you can) to reduce your electricity bill of everything else you have that's electric. When (if?) you get negative, then get an electric car. And only then go electric on the heating.

Under-floor heating is more efficient than forced air, and it can be electric or through a water heater, which could also eventually be electric. Plus a heat exchanger. Plus better insulation, and a programmable thermostat, plus... This is what I mean by spending money on other sustainability-related things.

Sadly, if you run the numbers on your roof size (especially when likely only some faces the sun - 1/2? 2/3?) and current solar cell efficiency (of the cells that will be installed, not some in-the-lab-only theoretical number), you probably can't heat your home with that, especially in the winter with reduced sun. That means you would need utility electric or gas, and until the electric grid is sourced by more renewables there aren't great options here. Furnaces don't last forever, so hopefully when you look into this next time...

And the next time you do any renovations, like your kitchen or bathroom, you can add underfloor heating. If electric, it will likely need its own circuit.

However, depending on your area, you may be able to sign up for power only from renewables, in which case go 100% electric (but it will cost you more money). And places like California are moving fast, so best options may depend on your location.

And while you're making these efforts, also write to all levels of your government for more renewables and less greenhouse gas. Annually. :)

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I suppose it would depend on your location - in my state most of our power still comes from coal burning plants so gas burns "cleaner" in my case (I don't know where our gas is sourced from, if it's fracked that would be another factor to consider).

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What kind of electric heating are you planning to use? Resistance heating, air source heat pump or ground source heat pump?

Resistance heating is a poor choice. 1 kWh of produced heat results in 1 kWh of electricity use, that takes 3 kWh of primary energy due to findings of Carnot. The 3 kWh will be either coal or natural gas, because all energy is marginal energy.

If you burn natural gas directly to heat, 1 kWh of heat requires only 1 kWh of natural gas. Thus, there is a 3x difference in the required energy.

However, ground source heat pumps can have a coefficient of performance of as large as 5. Then, 1 kWh of produced heat requires 0.2 kWh of electricity that takes 0.6 kWh of natural gas or coal to produce.

Air source heat pumps have a coefficient of performance of approximately 3. Then, 1 kWh of produced heat requires 0.33333 kWh of electricity that takes 1 kWh of natural gas or coal to produce.

Thus, air source heat pump: equivalent to natural gas.

And, ground source heat pump: very ecological.

And, resistance heating: don't even think if you plan to live in a sustainable manner!

Some could argue that you could purchase electricity from renewable sources. Well, hydropower is limited and not everyone thus can claim to use hydropower. If you purchase 1 kWh of wind power, and it isn't windy right now, you'll get 1 kWh of energy that isn't wind power. So, it's kind of cheating to claim to purchase renewable power without having means to store it and use the stored energy later.

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