> Incandescents are 100% efficient in cold seasons (heater AND light).
That's resistive heating, which is the most inefficient means of heating. Worse than natural gas or heating oil, and much worse than a heat pump.
That's resistive heating, which is the most inefficient means of heating. Worse than natural gas or heating oil, and much worse than a heat pump.
Worse than a heat pump, yes, but very arguable whether NG is more efficient. Arguably, NG powering central electric power generation and then used for resistive would be overall more efficient. Central NG will be more efficient and also there’s substantially less opportunity for NG leakage if piping was reduced.
NG is definitely cheaper (at least in the US), but that’s not really related to efficiency or emissions cost.
Also, if you’re in the electric ecosystem, swapping to heat pump systems will obviously be lower overall power in basically every scenario, and it gives an easy transition path unlike NG.
Maybe... I've got a NG furnace now and am looking at adding a heat pump, and even with a pretty expansive budget, I'm struggling to make the numbers work on actually removing the furnace entirely vs. doing heat pump + furnace. (And the near-impossibility of upgrading my home service past 100A makes it extra complicated if I want to electrify everything.)
If the evaluation is total lifetime cost to you, using the equipment you currently have almost always wins out. Same with purchasing more efficient hvac and such: the cheapest/lowest efficiency hvac is almost always the most cost effective. That tide could turn with sharp increases in NG or electric prices… but it hasn’t historically been true for many years.
It depends on the particular furnace or NG generator in question, but if you take the best case for each, then this does not appear to be true.
The most efficient combined cycle NG plant is around 65% efficient, without considering transmission losses. The most efficient NG furnace is 90+% efficient.
A 100 Watt light bulb consumes 100 Watts. It emits 100 Watts. That's 8,190 BTU every 24 hours, and it is perfectly efficient at doing this.
At $0.1745 per kiloWatt hour, it costs $0.419 to produce those 8,190 BTUs.
A natural gas furnace at 90% efficiency, meanwhile: Yeah, 10% goes right out the pipe and is lost.
But if natural gas costs $1.346 per therm, then producing 8,190 BTUs of useful heat costs closer to the realm of $0.123.
One thing costs about 42 cents. The other thing costs about 12 cents. 42 moneys is more than 12 moneys. :)
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I might opine that the most cost-efficient way of dealing with an incandescent light bulb is usually to immediately replace it with an LED bulb, and then landfill the old thing even though it still works.
4-packs of 100 Watt-equivalent LED bulbs are $12.97 at Wal-Mart, or about $3.24 per bulb. If it's the heating season and natural gas is being used at 90% efficiency, then replacing the incandescent pays for itself in about 300 hours of use. The LED will then continue to work and save money for thousands of additional hours.
Compare that to a modern NG furnace, which can be 90% efficient or more.
So if you just want heat, burning the NG directly is generally more energy efficient than burning NG to boil water to drive turbines to generate electricity and then converting that electricity back to heat via resistive heating.