The spot price for natural gas is $3.73 per million Btu
The spot price for propane is $1.005 per gallon
I’m not sure why they are measured differently, but is there some easy way to compare their cost ‘apples to apples’ in order to see which fuel is more expensive?
Propane requires a smaller jet orifice. Natural gas uses a larger jet. Appliances like space heaters or a gas dryer can easily be converted by switching out the jet orifice.
chart showing btu for natural gas and propane
The appliance uses Less propane compared to natural gas. So you can’t just look at the extra cost of propane. Less is used and that evens out the cost compared to natural gas.
1 gallon of propane = 91,500 BTU
Now - you can convert both to $ per BTU. This comparison is valid for purposes like home heating.
It’s not valid for comparison as automotive fuels since propane is a liquid and natural gas is a gas and needs high compression (CNG) or liquefaction (LNG)
There’s seems to be a glut of natural gas right now, due in part to all the fracking that is happening, and that has driven down the price, however the price of propane is higher that is has been historically, and I don’t hear anyone talking about a glut of propane. Does fracking not produce propane as well as natural gas?
My reference shows that liquid propane has a density of 510 kg/m[sup]3[/sup], and a HHV of 50.4 MJ/kg.
Which leads to…
25704 MJ/m[sup]3[/sup].
…
97.3 MJ/gallon.
…
92,222 BTU/gallon.
…
Ultimately, liquid propane at the price you listed gives you 87,831 BTUs per dollar.
For natural gas, your number becomes 268,096 BTUs per dollar.
If I’ve done my math right, that’s quite a disparity. Why the difference? My guess is that natural gas is more plentiful, especially with the fracking boom of late. Propane was also in very strong demand this past winter, when temperatures in the midwest were far below normal.
If by “less” you mean “less mass,” not true. My reference shows that propane and natural gas have nearly the same higher heating value. For X BTUs, you need y pounds of fuel, regardless of whether that fuel is propane or natural gas.
On preview, ninja’d by dolphinboy re: NG glut.
I’m just talking about home use (fireplace, stove and dryer).
If one gallon of propane creates 91,500 Btu, then it would take 10+ gallons to get to 1 million Btu. That means that 1 million Btu of propane would cost $10+, while 1 million Btu of natural gas is only $3.73, or 37% of the cost of propane. Is my math correct?
Why do I have a 1000 gallon propane tank buried in my backyard instead of a 1000 gallon LNG tank buried in my backyard?
Money.
LNG tanks need to be cryogenically cooled and CNG tanks need to be built to hold 3000 psi or so, whereas propane tanks run at a couple hundred psi.
Because natural gas is much harder to transport and store in tanks.
Part of the reason why consumers haven’t seen such a precipitous drop in propane prices is that the costs of actually delivering it add quite a lot to the price, and those costs are pretty much fixed relative to the commodity price. With natural gas, the transportation costs are minimal (assuming you have natural gas lines to your house) and so the price the consumer pays tracks a lot more closely to the actual commodity price.
LNG has very limited applications. A tank big enough to hold a useful quantity of LNG - and strong enough to keep it liquified - would be prohibitively expensive. It’s normally stored in low-pressure insulated/cryogenic tanks, where it’s allowed to boil off very slowly. If you’re not actively using it, then the boil-off is simply wasted. This makes it impractical for residential applications, where demand is intermittent. This is especially true in the summertime,when the only demand would be your water heater, assuming its not electric. The rest of the time, your tank of precious LNG is just slowly boiling away.
Propane, OTOH, can be kept liquid at room temperature at very reasonable pressures, less than 200 psi. It’s easy to make a tank that can do that.
(emphasis mine)
Is there a typo there? the two underlined statements seem to contradict each other.
*Is there a typo there? the two underlined statements seem to contradict each other. *
Not a typo, just not clear…
Because natural gas is much harder to transport via tanks and store in tanks.
That makes sense. Thanks for fighting my ignorance.
Propane is a refined petroleum product extracted from oil, whereas natural gas is, uh, natural pretty much as it comes out of the ground. Propane tracks oil prices, whereby natural gas has its own markets and pricing. Based on everything I’ve read, as well as conversations with friends who heat with propane, the cost to use propane for heating is about two to three times more expensive than natural gas. And closer to the three times mark now due to NG supplies and pricing, which corresponds to dolphinboy’s 37% figure. I’m thankful I have natural gas at my house.
You make it sound worse than it really is. Boil off rates for LNG is in the range of 0.05% per day. So - if you did not use any gas - in 20 days you will lose 1% of the gas !!
Moreover - the US and Canadian codes require LNG tanks to hold LNG without venting for a minimum of 5 days.
Not exactly as scary as you portray.
did you look at the BTU chart I linked? It has a table with all the numbers.
That’s not quite right. Propane production is mostly incidental, but mostly to natural gas production. Gas that comes right out of the ground is not ready to use-- it needs to be sent to a processing plant that removes the heavier hydrocarbons (including propane) and contaminants before it can be sent into commercial delivery pipelines. Right now about 75% of the US propane supply comes from natural gas plants with the rest coming from oil refineries. (Cite, PDF: http://www.npga.org/files/ICF%20Propane%20Supply%20Sources%20and%20Trends%20April%202013.pdf)
I see a chart showing the total energy flow rate in BTUs per hour for the two different fuels. Consider for example the very first entry, for an orifice drilled with a #75 drill bit. If you’re flowing natural gas at 4 inH[sub]2[/sub]O, your burner will deliver 1200 BTUs/hr of heat. If you’re flowing propane at 11 inH[sub]2[/sub]O, your burner will deliver 3080 BTUs/hr. Note that the supply pressures are quite different.
There is no mention of mass flow rate anywhere on that web page. Given that both fuels have nearly the same heating value (in BTUs per unit mass), I would expect the fuel mass flow rates to scale with the BTUs/hr listed in the table.
Both the government and propane industry say that propane is produced by both oil and natural gas in roughly equal proportions, 50/50. Otherwise, you’re right that I was simplifying the “natural” part of natural gas. it does need processing before use. In terms of pricing, it seems to track heating oil, but that may be as indicativeof competitive factors as much as the source.
I wouldn’t expect the source of Propane (crude oil boil off v natural gas condensate, or imports where you don’t know where it came from) would have much to do with the price. We know US natural gas production has increased somewhat in recent years. That’s enough to affect the domestic price significantly because it’s largely a closed system: NG produced in the US has to be used in the US, or at furthest in Mexico and Canada, with hardly any US LNG export yet (there’s the Kenai plant in AK, generally forgotten in the discussion of potential new LNG export plants in lower 48). But LPG/propane is much easier to store and transport, exported and imported from/to the US in significant quantities in LPG tankers, specialized but less exotic ships that LNG tankers, likewise requiring specialized but less exotic shore facilities. So it’s no surprise LPG’s price behavior is more like oil’s with a relatively (not absolutely of course) uniform world price, not the dramatic variations seen in natural gas prices in different parts of the world (sells for up to 4 or more times overseas what it does in the US), and with a relatively moderate impact, if any directly visible impact, on that price just because the US produces some more.
If you look at that cite I linked to, right now it’s about 75/25 from gas plants. It might have been closer to 50/50 in the past, though.
As for the prices tracking, I think that does have more to do with demand than where the propane actually comes from. The price of propane goes through the same seasonal patterns as heating oil, for obvious reasons. Of course also if you’re looking at the retail price instead of the spot price, high oil prices will also drive up the transportation costs which are a relatively large portion of the retail price of propane.