Which seems crazy to me. How is it cheaper and/or more efficient to create an entirely new system of gas pipes to every home so consumers can each inefficiently burn gas than simply converting the gas to electricity in a highly-efficient centralized plant and send the energy over the existing electrical infrastructure?
A modern gas furnace is very efficient, 95% or so. Really efficient gas power plants are only about 60% efficient. If you use the electricity to run an electrical resistance heater, it's more efficient to burn the gas directly for heat.
If you use a heat pump, you might get a COP of 3 or 4, which is effectively 300-400% efficiency. It's able to do this because it makes the outside colder while it makes the inside warmer.
Overall, the electric/heat pump system can be more efficient, but it has a lot more complex and expensive machinery, both in the home and in the power plant, and it's only been in the past 20 years or so that this has been practical. Many new homes are being built without gas hookups and use heat pumps instead.
when I looked into this for my house I found that gas was more like 10x cheaper than electricity. So a 3-4x efficiency advantage for a heat pump still made no economic sense
Depends on where you live, and how you get your electricity. Where I live, Idaho, electricity is very close to beating out gas for heating.
My gas costs $0.51 per therm, including distribution. When I consume electricity (more on that in a sec) it costs me $0.085 per kWh. On a straight therm to kWh basis, electricity is ahead.
But a single therm is equivalent to 29.3 kWh, so on an energy equivalent basis we've got $2.49 worth of electricity per therm of gas. So for 100% efficient electric radiant heat, electricity is about 5x more expensive than gas. That's close to the efficiency band of an air source heat pump, which tends to run in the 200-300% efficiency range, and geothermal might just beat out gas per BTU transferred into the house, especially if you include hot water consumption in that.
The extra complication is solar. Roof top solar is getting cheaper every single day, and for some of us the effective cost of electricity is $0. If you've got a rooftop solar system it's kind of silly not to switch over to electric heating if possible, since you can get your electricity cheap. Especially if you have net metering or a backup battery. If I didn't have a really high efficiency furnace in my new house, I'd probably have already done that.
Correct; unfortunately I can’t price that effectively for my specific house since I bought it with the solar, and can’t separate the numbers out cleanly.
That being said, we know that in the long run rooftop solar reduces electricity cost, because otherwise most people would never buy it. From my numbers above rooftop solar only needs to reduce electricity prices by ~40% to put them within striking distance of a heat pump being cheaper than gas.
Weird solution (or upselling by gas company) is co-generation system (power and bath warm water) at home. That's Available in Japan for a decade, it even use fuel cell.
A central generator plant may be more efficient than a house furnace. But electric heat is 1/3 as efficient as natural gas. I suspect it's a net win for gas heat, as modern furnaces are 80+ percent efficient.
You’ve got it backwards on the efficiency front. Burning gas for heat at home beats out most forms of electric heat efficiency wise.
A basic gas furnace is 80% efficient, with a nicer condensing unit being 96-98% efficient. Meanwhile most gas turbines hang out in the 32-38% efficiency range, plus transmission losses. Maybe if you’re using a heat pump and your local power plant is a triple pressure high efficiency model (~60% efficient) you might end up ahead, but for most users in most municipalities it’s actually better to burn the gas at home directly rather than at a power plant, at least for heat.
Wow, I had no idea gas power plants were that inefficient. And I suppose it's a lot harder to turn natural gas into heat to produce electricity with turbines at a power plant, which is then sent to homes to turn back into heat with resistive heaters than it is to just send the natural gas straight to the homes in the first place. I didn't consider that those extra steps would add up to such a high loss.
I’d call them semi -complementary from a consumer perspective and have different strengths and weaknesses, similar to phone and cable before.
My long term view is gas will go away first as electric costs go down and reliability goes up with local caches such as the PowerWall. Eventually usage will be light enough to cut the cable from long distance generation for close range neighborhood nukes.
I recently submitted an article, which after I read it, made me think the same thing. We could’ve had cleaner indoor air and fewer points of failure if just used electricity.
