The other day I talked about creating a SHTF battery recharging business. Well, one of the best reasons to do so–besides the potential business aspect–is the fact that a descent sized off-grid power setup gives you options, including the ability to run and recharge a variety of small electronics and, in this case, the ability to run an electric slow cooker. Why would you want to do that, you ask?
Well, while I certainly suggest you have a variety of methods of cooking food, including over a campfire, a wood stove, with propane and kerosene, and most definitely using the “best” source of free energy there is: in a sun oven, there may be times when your best option is to cook indoors but without using any liquid fuel (e.g., propane or kerosene) or firewood to do so. Again, it’s all about O.P.T.I.O.N.S.
In my opinion, there are really three major reasons why I suggest a slow cooker:
- it’s virtually hands-free cooking
- saves precious fuel resources for other uses
- you can make a slow cooker one of your more efficient cooking options with some tweaks
The Hands-Free Benefit
I would imagine that most of us have a slow cooker and use it on occasion. Ours seems to see more action during the winter because it’s a natural time for soups and stews, but that doesn’t mean it can’t be used at any other time. In fact, I’ve noticed that we’ve been using ours more and more lately which is nice because, despite the initial food prep time involved, it’s hands-free after that. You know, “set it and forget it.”
Now, just think about how useful this might be in an emergency or long-term, grid-down scenario. In particular, I’m sure you will have a wide variety of other tasks going on throughout the day and the last thing you want to do is to stand over a hot fire to ensure your dinner doesn’t end up char-broiled. Likewise, during the summer you certainly wouldn’t want to get the wood stove going (or even a campfire) just so you can cook a meal.
Using a slow cooker, on the other hand, frees you up to do any number of other tasks that would have otherwise been cared for with technology, from washing and sanitizing dishes to scrubbing the laundry, boiling water for a bath, and even gathering or treating water to consume. All of these actions that were once automatic now take away from your precious time and energy. The slow cooker eliminates this problem.
The Fuel Savings Benefit
Another benefit, in my opinion, is that by utilizing the power stored in your batteries, you can save your other fuel resources (e.g., gasoline, kerosene, propane, even firewood) for other uses, including heating and lighting. Granted, a major reason to stockpile these fuels is for cooking but if I can extend the life of these finite fuels for whatever reason I choose with a renewable one–in this case from my off-grid system–then that’s precisely what I want because I’ll have… wait for it… more options!
The Efficiency Benefit
For some reason I decided to look at the bottom of our slow cooker and noticed the wattage rating, which said 230 watts. I looked at that number and said, “hey, that’s do-able with my off-grid power setup” and then began experimenting. I should note that our slow cooker is an older 6-quart model with dial settings for “high,” “low,” and “warm.” And just so we’re clear, 230 watts (which is the high setting) at 120 volts (typical U.S. household voltage) uses approximately 1.9 amps of current per hour or a total of 7.6 amps in four hours (on the high setting) or somewhere in the range of 12 amps in eight hours (on the low setting) assuming roughly 3/4 of the total watts used on low. Did I put enough parentheses in there?
I also wanted to make sure our slow cooker wasn’t an anomaly, so I check out a few others that stated around the same wattage range, up to about 300 watts max. I looked online briefly but couldn’t find anything to to contrary so between 200-300 watts is what I’ll assume. Of course, there are other factors involved such as the size of slow cooker and I would imagine the newer slow cookers are more efficient but I haven’t tried to verify that.
The question, then, is how efficient is a slow cooker?
While I would like to report that it’s REALLY efficient and far better than even your home oven, I can’t do that. Unfortunately, a slow cooker will utilize the stated power per hour, every hour, while it’s running. Apparently, some of the newer models will automatically switch to a “keep warm” mode when it’s finished but that’s no big whoop if you ask me.
Anyway, back to a slow cooker’s efficiency, well, it’s not even more efficient than your home oven because, although your home oven does use more wattage per hour than a slow cooker (in the thousands of watts when running), your oven isn’t constantly using that power to heat the oven; instead, once it heats up the oven to the correct temperature it will kick the heating element on and off to keep the oven at the desired temperature. How much does this happen? I’m sure it depends on your oven and other factors but, by and large, it’s a fraction of the entire time you’re cooking. And, obviously, you won’t take 4-8 hours to cook a meal in your oven. Usually an hour or so and it’s done.
You can do the math yourself but if we use my slow cooker as an example we can say that it will use about 920 watts in four hours on high and let’s say about 1500 watts in eight hours on low (assuming 75% of total power on low). Compare this to a typical oven that would use approximately 4000 watts in an hour, if we assume it runs for only 15 minutes total (I haven’t tried to verify that but from what I’ve seen on the Net that seems to be a fair assumption) during the entire hour then it would use 1000 watts of power.
So, where’s the efficiency expectation, you ask?
Well, it comes from employing the wonder box technique (video). Essentially, that’s a technique where you heat food up and then enclose it in an very well insulated “box” of sorts. This idea is something I suggest everyone learn how to use and is, in fact, great for any meals where you can essentially heat it up and then let it slow cook or simmer. So, basically, you’re heating up the slow cooker for let’s say an hour and then insulating it very well inside the wonder box to retain that heat. You might want to come back every few hours and turn the slow cooker back on for a bit to ensure the heat stays at the proper level but from my few experiments this seems to work out just fine and I can get away with essentially running the slow cooker for maybe two hours total and still end up with a cooked meal. See?
One Other Reason to Consider This…
I can think of one other useful idea that I didn’t originally include in my list of three above: OPSEC. There are obvious OPSEC problems with cooking your meals outdoors–even in a sun oven–and if you can instead cook your meals low-profile, indoors, and without burning any fuel that sounds like a wonderful idea to me.
So, what do you think? Useful or not?