Generally speaking, the further north you go, the more prevalent gas/oil/propane is for heating and cooking. The BTU per $ efficiency for those sources is unmatched by electric. North-eastern and mid-western winters get cold and brutal. It's just not feasible to heat a home using electric in these areas without serious consideration put into insulation.
Rural homes, in my experience, use propane stored in tanks onsite, rather than natural gas piped in from a central source. And older suburban homes use onsite "heating oil" stored in tanks, usually in the basement, though, these homes are often converted to use nat-gas piped in from a utility.
> The BTU per $ efficiency for those sources is unmatched by electric.
I'm curious, with good insulation and modern heat pumps, does electric win these days? (Let's assume we're talking about winters that get down to 0°F at night, but not -30°F.)
>> modern heat pumps, does electric win these days?
Moving parts. Gas is more reliable in the very long term (10/20+ years) because it has fewer moving parts and operates at lower pressures than heat pumps. Gas is also easier to upgrade. Installing a larger furnace or water tank costs X. A new heat pump solution, 10x.
Heat pumps have a place but a New England winter is not that place.
"For climates with moderate heating and cooling needs, heat pumps offer an energy-efficient alternative to furnaces and air conditioners."
From what I've seen in Canada units that can only pump heat from inside to outside are sold as "air conditioners", units that can also pump heat from outside to inside are sold as "heat pumps".
More like winters that get down to 0° Celcius/32°F at night. Here in the Seattle area, if it gets close to freezing, the “strip heater” (supplemental resistive electric heating, like an electric furnace) kicks on. When I lived in Indiana, which most definitely has 0°F winters, the few that bought heat pumps hated them because the “heat pump” part didn’t get used for a few months in the winter while the real furnace did the work. Granted, that was 25 years ago, but physics hasn’t changed much: how much heat are you going to suck out of 0°F air?
The heat pump does a much better job of cooling the house in the summer in comparison to a gas furnace, though.
How does that look for Geothermal heatpump, where you drill down a borehole and 'steal' heat from the ground? The temperature of the ground does not vary much seasonally.
Geothermal heat pumps (aka ground sourced heat pumps) have a high initial capital cost. Their suitability also depends on the local dirt as much as the local climate. You need good enough ground moisture levels to have a high enough thermal conductivity. Otherwise the cost of the hole becomes prohibitive.
Well, speaking of Indiana, I worked at a church in IN that used the type of geothermal you describe. Kept the church warm all of the two or three winters I was there. IIRC (and I probably don't from 25 years ago), the ground temp was around 54F at the depth it was pulling from.
Insulation is very relevant for sizing the equipment, but has comparatively little influence on the $/BTU.
Hand-wavy, order-of-magnitude estimates here.
82% blended efficiency gas equipment is ~$15/1MBTU
Geothermal heat pump at a blended COP of 3 will take ~100kWh for that same 1MBTU. In MA, that 100kWh will cost you $20. (That's after a potentially $75K-100K installation cost for the geothermal wells and equipment vs $10K for a decent modcon boiler.)
So, pay an extra $50K-90K up-front and 33% more for your variable energy. (Of course, you get air-conditioning included above in most of the geothermal installs.)
I think that the issue with heat pumps is that they don't really work well in sub-freezing temperatures, making them mostly useless in colder climates.
There are dual fuel systems that use heat pumps until they stop working and switch to heating using a regular furnace. They cost a little more but they provide some marginal savings (even if those depend on the cost of both electricity and whatever fuel the furnace uses).
My NYC apartment has a modern heat pump and it certainly works when it's 0°F outside which is well below freezing -- according to its specs, it's still more energy-efficient than electric coil heating as long as the outdoor temperature is above something like -10°F.
So it's not for extreme cold (-30°F), but it can absolutely handle a wide range of sub-freezing temperatures.
First off, due to the physics of their operating mechanism, heat pumps can only provide heat down to a certain temperature. Some can operate at temperatures as low as 0°F (albeit inefficiently) but even for those models, the efficient minimum temperature is still around 25°F. So if you live in a place that gets colder than that, and you insist on electric heat, you would likely need to go for resistive heating (like wall heaters). But resistive heating is not great, in part because it dries out the air so much.
In terms of cost, I happen to have both a high efficiency gas furnace and a high efficiency electric heat pump in a home with great insulation, and have been able to experiment with how they compare for heating the home. We don't get winters that go below 25°F, but gas heating is FAR cheaper (I estimate less than half the cost). We personally feel the air quality is better with gas heating as well, although this might be subjective.
> It's just not feasible to heat a home using electric in these areas
I live in Massachusetts and the cheapest source of heat is an electric, air-based heat pump matched with solar panels.
Without solar, electric air-based heat pumps are cost competitive. You have to do the math, though. (How much BTU per therm of gas or gallon of oil; reduce by efficiency, then convert BTU to kwh, then divide by the COE of your heat pump.)
At my old house in Massachusetts I paid $0.12 per kwh, my gas price was equivalent to paying $0.04 per kwh to run a resistive heater; a heat pump with 3.0 COE would be "break-even" with gas.
At my current home my solar loans are estimated to cost about $0.04 cents a kwh. Obviously, I went with a heat pump instead of a gas furnace!
Was that $0.12/kWh the all-in cost or just the power cost? Also in MA, I pay about that for the power, but an additional $0.09/kWh or so for the transmission/distribution of that power.
The total delivered price is $0.19xx for me per marginal kWh and seems to be close to that across MA.
Rural homes, in my experience, use propane stored in tanks onsite, rather than natural gas piped in from a central source. And older suburban homes use onsite "heating oil" stored in tanks, usually in the basement, though, these homes are often converted to use nat-gas piped in from a utility.