Recently, I dug my "Presto Hot Dogger" out of it's resting place deep in a kitchen cabinet, and began thinking. (always a dangerous thing!) The Presto Hot Dogger is probably the simplest kitchen appliance ever devised by the mind of Man: No moving parts, no adjustments, not even a heating element! It is designed to do one thing only, and that is cook hot dogs. It cooks the hot dogs by "electrocuting" them; in other words, it passes the current directly through the hot dogs in order to heat them up, just like the "Two Forks" hot dog cooking method, but without the hazards of unprotected AC voltage. (The "Two Forks" method uses a fork in each end of the dog, and an AC cord with alligator clips connected to the forks.)
I suddenly thought, "I wonder how much power it takes to cook a hot dog? And how much does it cost?"
Voila!! A Science Project is Born!
Goal: Investigate the actual cost, in US dollars and time, of cooking one hot dog using various methods.
Method: The unwilling victims were Hebrew National Bun-Length hot dogs at refrigerator temperature of approximately 38 degrees F. Done-ness is determined by the temperature of the finished dog, with 140-160 F being judged to be a good eating temperature. 140 F is judged by my mouth as a pleasant eating temperature, while anything over 160 F is perceived as "Too Hot."
Actual dog temperature was sometimes determined by taste (in the case of the microwave; I was hungry), and sometimes by infrared thermometer or probe thermometer. All the dogs were personally consumed by the principal investigator (me), at the close of each experiment.
These experiments are arranged in order from most expensive to least expensive. Cooking time is also given, because sometimes speed of cooking is more important than economy of cooking.
Note: kWh stands for kilowatt-hour, the usual measure of electricity usage. My electric bill says I'm paying 12.16 cents per kWh.
Step 1: Charcoal Grill - 24.44 cents, 29:30 minutes
Charcoal costs between .60 and 1.00/lb in the grocery store, depending on whether it's the self-lighting variety or the old-fashioned kind. I chose to use a house brand of self-lighting charcoal, in a small bag. The cost is roughly 85 cents/lb.
I re-purposed my gas grill to charcoal for this phase, placing the briquettes on top of the lava rock. Three briquettes are enough to give sufficient coverage for one hot dog. After lighting, 20 minutes were allowed to elapse before placing the hot dog, as per the instructions on the bag (Ready in 20 Minutes, Guaranteed!). This time must, of course be added to the total time of cooking.
After 9.5 minutes of cooking, the hot dog was at an internal temperature of 158 degrees F.
Three briquettes weigh 4.6 ounces. That's 24.44 cents worth of charcoal. Granted, more dogs could have been cooked with the same charcoal, but 3 briquettes is the minimum for cooking one dog.
Step 2: Gas Grill - 14.85 cents, 12:30 minutes
I lit my propane grill, and after a warm-up of about one minute, placed one hot dog on the grill. This is a two-burner grill, and only one burner was necessary for one hot dog. After 12 1/2 minutes (including warm-up time), the hot dog's internal temperature was 150 degrees, suitable for eating.
Propane weighs 4.2 lbs/gallon. My gas grill uses roughly 2 lb. of propane /hr with both burners on medium heat, or slightly less than 1/2 gallon, or about $1.50 worth of propane per hour, with both burners going. (This estimate assumes a propane price of around $3/gallon.)
12.5 minutes is .208 hours. One burner uses 1 lb/hour of propane, thus I used .208 lbs of gas, or .0495 gallons. At $3/gallon, that works out to 14.85 cents.
Step 3: Electric Stove- .988 cents, 3:45 minutes
The hot dog was placed in a shallow pan, with enough room temperature water to cover it, and heated on a small electric stove burner set to high. After 3 minutes, 45 seconds, the hot dog was at roughly 154 degrees, measured by IR thermometer. Electricity in my neighborhood costs 12.16 cents/kWh. Small electric stove elements are typically 1200-1300 watts. We'll use the 1300 watt figure for the calculation.
3 Minutes, 45 Seconds is 0.0625 hours. So, drawing 1300 watts for .0625 hours = 81.25 watt-hours or .08125 kWh. Multiplied by 12.16 cents, it cost me .988 cents to cook my hot dog on the stove.
Step 4: Microwave Oven - .1621 cents, 1 minute
One hot dog was placed on a paper plate and heated on high power in my microwave oven for 60 seconds, which may have been slightly too long. (Note to self: prick dog with fork before cooking in microwave, otherwise it'll spurt juice all over!) No temperature reading was taken, but the dog was at proper eating temperature. (It was delicious!)
My microwave oven is an 800 watt model. 800 watts for one minute is 800 watt-minutes, or 13.33 watt-hours, or .0133 kWh. Multiplied by 12.16, that's .1621 cents. Not bad! I can cook 6 hot dogs for 1 cent!
Step 5: Electrocution - .051072 cents, 2 minutes
The Presto Hot Dogger has large prongs on the inside that the user places the hot dogs onto. The circuit to the power cord is completed when the part with the prongs is slid into the outer case. I placed one hot dog on the prongs and cooked for 60 seconds, the recommended time in the instructions. But, "Your Hot Dog May Vary." The Hebrew National brand must have higher internal resistance than a generic hot dog, because it took 120 seconds for the hot dog to reach eating temperature.
I used a "Kill-A-Watt" watt meter to find the power draw of the Hot Dogger. Unsurprisingly, the power draw changed as the hot dog heated up, starting at 66 watts and gradually going up to186 watts over the course of the 2 minute cooking time, as the hot dog's internal resistance decreased with temperature. I don't have the instruments to determine whether this was a linear rise, so for the purposes of this project, I will add the starting wattage and ending wattage and average the two. The average is 126 watts, over 2 minutes, equaling 252 watt-minutes or 4.2 watt-hours, or .0042 kWh. Multiply by $.1216/kWh and you get 0.051072 cents. Wow! I can cook 19 1/2 hot dogs on this thing for one cent!
Step 6: The Free Methods - 0 cents, time varies
Even though it's February, it is Arizona, so I decided to see what would happen using this method. At an ambient temperature of 74 degrees (Sorry, you folks in Maine!), I constructed a solar oven out of a potato chip can covered with a plastic bag, just big enough for one hot dog. This was placed in the afternoon sun for 1 hour, and the temperature was obtained. The finished temperature of the dog was 111 F, definitely not optimum, but still edible.
This would obviously work much better in the summer. Also, it's only totally free if you fish the chip can, foil, and plastic out of the trash.
Some guy actually once published a cookbook of "automotive recipes," which detailed how to cook simple dishes on your car's exhaust manifold. (I think he was a traveling salesman!) There was even a companion cook-pot that bolted onto the engine so your dinner wouldn't shake loose and wind up as buzzard bait on the road. Modern cars aren't so cooking-friendly anymore. Most of the hot areas are so buried under the hood or covered up with plastic that it's difficult to find a good cooking spot. I decided not to try this method, because I couldn't find a good place on my engine. Also, I was out of hot dogs.
I'm guessing, however, that a 30 minute trip (starting with a cold engine) would suffice to heat the dog. The method is to simply seal the dog well in foil and place somewhere on the engine where it won't fall off.
Caveat: This method is only free if you're going somewhere anyway, and if the cost of the foil wrapping is negligible.
I also did not try this one, because I don't have any burnable wood handy, and I'm out of hot dogs. It would probably take around 15-20 minutes, including building the fire, and the only cost would be the match, if you gathered wood instead of buying it.
I once heard a yarn about some Air Force guys who got bored and hungry, and decided to roast their hot dogs in front of a fighter plane's radar dish. This is perfectly plausible, since radar is the same thing that cooks food in a microwave oven. (Why do you think the first microwave oven was called a RadarRange?) The microwave oven was invented by a researcher who had a chocolate bar mysteriously melt in his pocket while experimenting with a radar transmitter!
While this method would be free for the airmen involved, it would certainly have cost the Air Force (Read: Taxpayers) $$$, and the poor slobs downrange of that radar dish might have had some objections, too. Not to mention the risk of losing stripes if the Commanding Officer got wind of it!
Needless to say, not being in the Air Force, (and being out of hot dogs) I did not try this method. Would've been fun, though.
Step 7: Conclusions: I'm not Hungry Now!
All the experiment subjects were eaten with copious quantities of mustard, and all were, as far as I can judge, equally tasty.
This was an interesting experiment. Science Projects are always more fun if you wind up with something either edible or practical!
There were a few surprises. I expected the Presto Hot Dogger to be the cheapest non-free method, because heating something directly should always be more efficient than heating it indirectly. It's a great pity that the Hot Dogger has been out of production for about 30 years, and there has never been an equivalent product that I'm aware of. You can, of course, use the Two Forks method mentioned in the intro, but you do this at your own risk (Of fire, electrocution, or blown fuses), because you will have exposed AC voltage all over the place. If you choose to do this, be sure you know exactly what you're doing, pay close attention, and make sure that no children, pets, or other living things have access to your cooking area!
I also expected the microwave oven to have a low cost, and it did. Transferring energy using microwaves is much more efficient than doing it with heat.
It was somewhat surprising that charcoal, the method that cost the most, also took the longest (Not counting solar, which is highly variable).
I did not expect the price of cooking on a gas grill to be so high, nor the electric stove to be so low. I guess the hot dogs are not what's running up my electric bill. Maybe it's this computer!
If anyone ever thought a charcoal or gas grill was a cheaper alternative to cooking in the kitchen, this result might change their minds. Bon Appetit!