$ / “Gallon” of Electricity

Earlier I did a broad look at the cost of various camping fuels and how much it took to boil a cup of water. This was based on store costs and actual time to boil for alcohol and an electric stove burner.

There is another way. Looking at the theoretical energy in a unit of fuel or kW-hr for electricity. While this ignores things like the preheat time it takes to get a gasoline stove running, versus the near instant of an alcohol burner, and the heat loss heating up the electric element on the electric stove; it is a more direct comparison of just how much you are paying for that energy, however you use it.

I’m going to be using traditional American units in much of this. Nothing prevents using Metric units, but they have chosen sizes that are not very intuitive to grasp, and generally screwed around names (by naming things for people instead of function) in a way that makes things less than obvious what a unit means at times. For those limited in ability to only doing metric, well, it’s not necessary to follow the details (or you can learn how to do the conversions). It really doesn’t matter as it’s the math relationship that matters, not the units in which it is done.

With that, the first table we need is is a way to convert some fuels and kW-hr of electricity to a standard of heating energy. For that I’m going to use a BTU table. British Thermal Unit. Heat to warm a fixed amount of water a fixed amount. (One pound, one degree F).

http://www.exothink.com/Pages/btu.html also
https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent

Fuel          BTU
kW-hr         3413
Methanol     56800 / gallon
Ethanol      76100 / gallon
Propane      21699 / lb
Propane      91000 / gallon
Butane       21300 / lb
Butane      102600 / gallon
Gasoline    114000 / gallon
Kerosene    128000 / gallon
Diesel #2   129500 / gallon
Coal         12500 / lb

We easily and often see the price of a gallon of gasoline or Diesel oil, so it is convenient here to think in terms of “GGE” or Gallon of Gasoline Equivalent. It gives an instant intuitive grasp.

My baseline electric rate here is 19¢ / kW-hr. Over some small usage you jump to 32¢ /kW-hr. What is that in GGEs? Or how much would it be priced for the same BTUs in gasoline?

114000 / 3413 = 33.4 kW-hr / GGE. Which also matches the value in the Wiki page, so a nice cross check. Now let’s figure out what the GGE costs.

33.4 x $0.19 = $6.35 / gallon as a gasoline equivalent. Gee. So at my very cheapest rate, electricity is priced way higher than gasoline. Now that’s assuming the conversion to useful work is similar. For things like light or running a TV set, it clearly isn’t. But for many things, it is. Heat is a great example. Both an electric heat element and a flame are about 100% efficient in making heat.

I also find it satisfying that when I looked at the actual costs / burn; I got break even at about a $6 rate for a gallon of fuel. This implies I was pretty close and not making some terrible mistake like slipping a decimal point.

But I’m essentially 100% of the time using way over the “baseline” electricity amount. ANY displaced consumption will come out of that higher marginal use. What’s that in GGE terms?

33.4 x $0.32 = $10.69 / GGE. YIKE! I’m paying almost $11 / gallon for my electricity! At that price there’s a lot I can do to cut electricity use by substituting cheaper fuels.

Last time I looked, there was a $0.50 / kW-hr tariff filed with the PUC. They were expected to approve it. I’ve not seen it yet, nor seen a giant jump in my bill, so it is likely still being contemplated. I suspect even the PUC and California Dimocrats have had a lump in their throat over the nice “round” number of $Half A Buck.

33.4 x $0.50 = $16.70 / Gallon (of gasoline equivalent). It’s not hard to see that at this level, you can easily afford to run your own generator, even if 2/3 of the energy goes up in hot exhaust. A general rule of thumb that only works in American units, is that if you take the price of Diesel fuel in $/gallon and shift the decimal point one over, you get the cost of fuel in generating electricity with a Diesel Generator. At the moment, Diesel is running $3.75 / gallon, so it would be about $0.38 / kW-hr. Significantly below $0.50 / kW-hr. Just sayin…

But if your goal is just heat, you can skip all the heat losses in a Diesel Generator. To put an even finer point on it, you could burn that Diesel in a co-generation unit and use the 2/3 that’s “waste” heat for something productive, while making electricity at a profit. (My local school did this. Installed a Capstone Micro-turbine co-generator unit. They use it to heat the swimming pool used for P.E. They use the same gas they ever did, but now get “free” electricity.)

So, for me, using my Coleman Gasoline stove is a very clear “winner”. I’m using $3.25 / gallon fuel to replace $10.69 / GGE electricity. Even using White Gas (Walmart, $7 and change / gallon) is a big win until I’m below the baseline threshold.

In actual measured time to boil, the electric element on my stove took so long to reach red hot, that even alcohol fuel at $10 / gallon was a win. The fuel I’m using is an unknown mix of ethanol and methanol, but some estimates put it at about 1/5 methanol. That would be 11360 BTU. The ethanol contributing 68800. Total 72240 BTU / gallon. That makes it about 72240 / 114000 or 0.63 of a gallon of gasoline. $10 / 0.63 = $15.87 / GGE. If instead I bought racing methanol fuel, it runs about half that, so about $7.80 / GGE. Bulk commercial methanol is about 1/2 that again and clearly a big win.

Yet in actual boil time, alcohol was a net energy cost win. That implies a large percentage of the heat to boil one cup of water goes into the burner and the air on the electric stove. This can be observed in a very long time at full power to start glowing red. This implies very long cook time items would be more efficient by a lot than very short time items like a cup of water. Avoiding burner pre-heat time is a big deal. But this is an interesting benchmark for Real World cost savings. Moving a bunch of short coffee / tea kettle runs to a fuel stove can save $15 / GGE on electricity. MANY fuels meet that hurdle rate!

This also implies that more precise measurements of actual run times / energy costs for different lengths of cook could be a big benefit.

How about Propane? A one pound camp cylinder runs about $3.35 each A pound is 21,699 BTU (lets just call it 21.7 kBTU). 114,000 / 21700 = 5.25 lbs propane / GGE. $3.35 x 5.25 = $17.58 / GGE. Oddly, it too is very fast and efficient at heating a cup of water. So close to a win compared to slow electric elements in actual timed tests. But can we beat it even more?

Locally, propane sells for about $4 / gallon in 5 gallon tanks. I know, in places like Florida it is closer to $2.85 and in Texas down near $2.00, but I don’t live there yet. At 91,000 BTU / gallon that’s 114000 / 91000 = 1.25 price multiplier per gallon to make them comparable, or $5 / GGE for propane in the bigger bottles. Well under the $6.35 / GGE for baseline electricity even before you allow for the poor efficiency of the thick electric elements on short heating tasks.

So that means it’s VERY profitable to use a back yard propane stove to do your cooking. That’s the burners part of it. A lot of gas is used in a gas grill and there isn’t really an equivalent indoor unit in most homes (too much smoke so you need a big fume hood). So I don’t really have a way to compare their relative performances.

One last note: Natural gas, here, is dramatically cheaper than just about anything else. It is measured in Therms and each of those is about a GGE already. IF (and it’s a very big IF..) I’ve picked the right tariff and guessed right, it is running between $0.50 and $2 / GGE summmer vs winter. At that rate it beats everything else.

Clearly THE biggest winner is just putting in a natural gas stove. But close behind it would be a natural gas generator or co-generation unit.

Now those are not small things a guy can just do on the weekend. Setting up a propane stove and cooking on the patio is easy for all of us to do.

In Conclusion

An electric range is not very efficient on fast cook items due to the long warm-up lag. For those things, even alcohol fuel bought in cans is a net small win. Yet even a modest shopping for cheaper bulk fuel makes the alcohol stove a big win.

Many other fuels are also big wins. Gasoline is clearly one, yet even white gas in cans beats the non-lifeline rate.

Propane in the standard BBQ size cans is also a nice win, even for baseline rates.

The biggest win, though, is the natural gas service. Converting appliances is not cheap and not easy, though, so best left for a longer term remodel project.

For now, that back yard propane Man Stove is looking like a sweet deal. Add a trip to the drag strip to pick up a 5 gallon jug of racing fuel for making morning coffee with the camp stove spirit burner, a lot of the household cooking can rapidly be moved off of the (very expensive) electric bill.

This will just get ever more profitable as more wind and solar boondoggles are added to the grid.

Folks in other countries will need to “run the numbers” for themselves based on local prices to decide what is the most economical way to cook some meat, flip some eggs, and make coffee. For me, it’s clearly worth it to use my Coleman gasoline stove, and I’ve been doing that. It has a large warm up time too, so mostly just used for whole meals with a long total burn time. One off coffee and tea I’m still doing on the spirit burner. As summer drags on (and I get the patio cleaned up) I’ll be finding my propane gear and setting up to refill my own 1 lb propane canisters. At that point, making morning coffee on a one burner propane job on the counter will be my regular method.

As I do like the spirit burner for being silent, I’m also going to see where the nearest drag race fuel stop is located. Some 20+ years ago I bought a 5 gallon jug of it. Then it was a little store front about 10 miles from here. I’m hoping something like that is still around. Price was not that much higher than industrial bulk, and far less than in stores in cans. Since there is still drag racing here, I’m pretty sure the State has not driven that fuel into the land of unobtanium… Though I do think they converted from straight methanol to an ethanol base. Anyone with info on that speak up!

With so many fuels “profitable” (natural gas, propane, gasoline, alcohols) I would expect more folks to start shutting off the AEK and breaking out the camp stoves & backyard grills. This isn’t rocket science… even if flame and pressurized gas is involved ;-)

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
This entry was posted in Economics - Trading - and Money, Emergency Preparation and Risks and tagged , , , , , . Bookmark the permalink.

18 Responses to $ / “Gallon” of Electricity

  1. Sandy MCCLINTOCK says:

    Thank you :) Natural Gas has doubled in price in Australia due to the Greenies successful campaign to stop fracking.
    I recon a microwave oven must be reasonably quick and efficient at boiling water (2 – 3 mins) or cooking a potato (5 minutes). … remember to break the skin with a knife to prevent explosions ;)

    If a microwave uses 1000 Watts and electricity is 20c a KWh then 5 minutes is 20 /60*5 cents = 1.6 cents. (In Australia peak rate electricity is up to 40 cents a KWh!)

  2. p.g.sharrow says:

    Electricity cost is measured in mils per Kw, IIRC. Mils per dollar, 32 mils = 3.2 cents or $0.032 and not 32 cents. 32cents would be 320 mils. I pay the same here as an Ag user…pg

  3. p.g.sharrow says:

    well, you made me look it up, below is Public Graft & Extortion’s latest tariff electric rate.
    $0,32 per Kw or 320 mils! plus extras = 399,8 mils total charges…pg

    Total Energy Rates ($ per kWh)
    PEAK
    Summer
    Total Usage
    $0.39980
    (I)
    $0.32423
    (I)
    Baseline Credit
    it (Applied to Baseline
    Usage Only)
    ($0.08581)
    (I)
    ($0.08581)
    (I)
    Winter
    Total Usage
    $0.28183
    (I)
    $0.26754
    (I)
    Baseline Credit
    t (Applied to Baseline
    Usage Only)
    ($0.08581)
    (I)
    ($0.08581)
    (I)

  4. Pingback: $ / “Gallon” of Electricity – HiFast News Feed

  5. E.M.Smith says:

    As you worked out, a mill is 1/1000 of a $ or 1/10 ¢

    https://en.wikipedia.org/wiki/Mill_(currency)

    The mill or mille (₥) (sometimes mil in the UK, when discussing property taxes in the United States, or previously in Cyprus and Malta) is a now-abstract unit of currency used sometimes in accounting. In the United States, it is a notional unit equivalent to ​1⁄1000 of a United States dollar (a one-hundredth of a dime or a tenth of a cent). In the United Kingdom it was proposed during the decades of discussion on the decimalization of the pound as a ​1⁄1000 division of the pound sterling. Several other currencies used the mill, such as the Maltese lira.

    The term comes from the Latin “millesimum”, meaning “thousandth part”.

    I find it interesting that it looks like your region gets seasonal price changes and three tiers. I need to check it, but I though here we only had 2 tiers and no seasonal change. (PG&E has different tariffs in different places). Where A. Watts lives they have an optional time of day tariff that runs 98 ¢ / kW-hr summer mid-day when AC demand is greatest. IIRC it only exists in the hot Central Valley. There it would make sense to use a gasoline generator to run your AC. Even a cheap inefficient one!

    IF I read your quote right, your summer peak is just under 40 ¢/kW-hr. Wow! That’s one expensive lunch! I suggest sprucing up that patio stove / oven you mentioned before!

    @Sandy MCCLINTOCK:

    Oh yeah, the food nuker… guess I ought to do the 8 oz test in it too. That is a very viable option.

  6. E.M.Smith says:

    @P.G:

    Your 39.98 ¢ peak tariff runs out to:

    33.4 x 0.3998 = $13.35 / Gallon (GE) for electricity… At that rate it ought to be profitable for you to run a small Diesel generator and make your own… Certainly profitable to substitute direct fuel driven power for electric motors (so things like engine driven water pumps – though there you could just irrigate off peak times).

  7. Ed Forbes says:

    Diesel becomes a better buy in California for generators if you buy the “red” fuel that is not taxed for road use.

  8. E.M.Smith says:

    A US gallon is 3.7854 L, so to convert the $/gallon to L just divide by that.

    39.98 ¢ electricity is $13.35 /GGE or $3.53 / L (GE)
    32 ¢/kW-hr is $10.69 / GGE or $2.82 / L GE
    19 ¢/kW-hr is $6.35 / GGE or $1.67 / L GE
    $7.80 / GGE race alcohol is $2.06 / L GE
    $5 / GGE propane is $1.32 / L GE
    $3.78 / gal. gasoline would be $1 / L GE
    $3.25 / gal. RUG now is 86 ¢ / L GE

    I’ll leave the rest of the metric conversions for anyone who wants to do them, along with the hundred plus potential local currency conversions. As the GGE unit came out of US Fuel Economy law, I’m not sure if there is a real metric equivalent or what it might be, but figured the LGE was likely most useful as I think most of the world sells gasoline in “currency”/L units, maybe…

    I’m pretty sure nobody is using the Imperial Gallon any more, so I’m not going to do that one. I do miss those loverly large quarts of oil and magnificent pints of beer… Fond memories of a Canada long ago…

  9. Greg Hall says:

    After reading your post I decided to do some detailed cost analysis for Kerosene, 1st at my price and again at the Lowes price of $44 per 5 gal.
    @ $3.35/gal. a Perfection “High Power” burner on one of their ranges uses 0.142222 oz per minute of Kerosene, costing $0.0037222 per minute of operation at High Yellow flame. Or, 0.6399999 oz of Kerosene, costing $0.0167499 to boil your one cup of water.
    Now to recalculate for the Lowes 5 gal. can of K1 @ $44 per can which now is costing $0.0097777 per minute of operation at High Yellow flame. Or, 0.6399999 oz of Kerosene, costing $0.0439999 to boil your one cup of water.
    So even at the extremely highLowes cost it is still only 1 penny per minute of operation or 4.3 pennies to boil your 1 cup of water for coffee.
    And all the above is on a full size range, not a camping stove.

  10. E.M.Smith says:

    @Greg:

    Thanks for that! As my kerosene gear is not close to hand, I’m very grateful someone has “pitched in” with the help! So 1.6 ¢ / cup on the low cost kerosene, but even high cost $8.80 / gallon Lowe’s by the jug is running 4.3 ¢ that isn’t bad.

    I also did a test using the microwave, just to round things out, and posted it back on the stove fuel cost topic. It cost 2 ¢ / cup to boil, even in the microwave. So your lower cost kerosene beats even the super efficient microwave! I’m pasting it here, too:

    Did a test with the microwave. 1.5 kW took 2.5 minutes to boil 8 oz. cold tap water in a pint cannig jar (lowest mass microwave transparent heat stable container I have with water roughly a right circular cylinder. That worked out to 2 ¢ to boil vs 3.2 ¢ estimated on the range.

    We saw above that stove alcohol was running me 2.32 ¢ / cup to boil, so the microwave beats it by 1/3 ¢ (but I’m going to keep using the alcohol stove ‘cuase fire is more fun and it is silent and first thing in the morning silent matters ;-) almost as much as late at night… )

    https://chiefio.wordpress.com/2018/03/22/60-120-per-gallon-camp-stove-fuel/#comment-92683

    GIven propane in canisters was running about 1.6 ¢ that means any of these is cheaper than even using my microwave oven to boil water:

    unleaded gasoline
    white gasoline
    Bulk Kerosene (see Greg test above)
    BBQ tank propane
    canister propane
    racing fuel alcohol

    and that even “by the quart at Walmart” stove alcohol is roughly a wash.

  11. Another Ian says:

    On fuels

    “The PBS Newshour Whale Oil Myth”

    https://wattsupwiththat.com/2018/04/24/the-pbs-newshour-whale-oil-myth/

  12. erl happ says:

    Well, these packaged fuels are very convenient there’s no doubt about that. But I enjoy the flavour of meat cooked in a wire rack over some eucalyptus twigs and leaves. I have trees at hand always dropping stuff. I have a cottage on a farm yet to be connected to the electricity grid. So I am inclined to use an open fire and when it comes to boiling the kettle use a ‘rocket stove’ something like this: http://www.bristolrocket.com/

    There is something nice about being self reliant.

  13. jim2 says:

    What with all the talk about stoves a while back, I liked the look of the gasoline one.

    https://www.amazon.com/Portable-Travel-Camping-Gasoline-English/dp/B00RR0DZG2/ref=sr_1_1?s=sporting-goods&ie=UTF8&qid=1524621003&sr=1-1&keywords=Portable+Travel+Camping+Fuel+Patrol+Gasoline+Primus

    I didn’t realize it shipped from the Ukraine or somewhere thereabouts. Finally arrived and I haven’t had a chance to fire it up. It’s heavy, but don’t yet know if it’s well built.

    I’ll let you know once I find a roundtuit.

  14. Larry Ledwick says:

    I am still waiting for mine to arrive, I figure they had some little old lady in Tibet knit it out of Yak hair.

  15. Sandy MCCLINTOCK says:

    A friend in Canada (who worked for their “Hydro”) told me the retail cost of electricity is going up to 8c/KWh – that’s a whole cent more! Their Hydro is far cheaper to run than renewables but their politicians want to be seen to be green and so are adding expensive wind power into their mix. (!)
    I am amazed that Hydro is seen as non-green.

  16. philjourdan says:

    @Another Ian – Re: Whale oil

    The premise that not taxing an item amounts to a subsidy is based on the old “L’Etat c’est moi!”. Or that the royals (government) own everything and what they let you keep is a subsidy. You cannot convince a socialist of anything else and that paper is merely more evidence of the economic ignorance of most folks these days. They have not gotten use to the concept of private property rights (and indeed the UN is trying to rid us of them).

    E.M. is probably have heartburn over that paper.

  17. E.M.Smith says:

    I was wondering where that ass-backward thinking about subsidy originated…

    Not heartburn so much as as desire to shout and write an article ;-)

    Whale oil stopped being used because we’d hunted whales to the point where it became scarce and expensive, so substitutes were created. The winner of that race was kerosene; and at such low prices ihat it then killed off what remained of the whale oil industry. Then later, kerosene as lighting was reduced to a niche use as electricity substituted. Nothing more.

  18. E.M.Smith says:

    @erl haap:

    I’m all for farmed & free fuel.

    Just don’t have enough on my lot AND the CARB (California Air Resources Board – AKA Air Nazis) have essentially banned burning. I can ONLY get away with an outdoor fire if it is in a BBQ of some kind AND is of appropriate size and composition to look right AND I have a plate of meat (or similar) sitting next to it to BBQ. This was told to me by the nice man with the badge and the big fire truck as he was “inspecting” my big brick BBQ with some trash wood being burned in it… I said the meat was in the fridge until the coals got going, so he “let me off” but said next time he needed to see a platter of meat next to the BBQ; or I’d be written up for some un-Godly number of $$$ fine for destruction of air quality or some such.

    That, in fact, was part of what induced me to make the POB BBQ as it was clearly small and had a grill on top and would not make as much visible smoke. It also induced me to keep a package of cheap hot-dogs in the freezer that can sit for a couple of hours on a plate while I burn small bits of trash wood in the big BBQ… “Just waiting for the hot dogs to defrost while I get some coals going, officer…”

    At one time I’d sized the lot I’d need for poplar & eucalyptus to have enough wood for heating and eating. Wanted to get a square somewhere in the boonies. Now I’m thinking an RV in an RV park in Florida most of the time, but a small patch of “back woods” I could drive to when desired for fishing and BBQ in the woods. Enough rough wood on it for anything I’d need or want… But the spouse wants lawn mowed by the gardening service and the pool in waking distance… and the “BBQ” catered in the club house… Maybe we need 2 RVs ;-)

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