Two pots, wet sand, and a wet blanket seems to be all that’s required to keep food from spoiling for up to 3 weeks. Check out the Pot-in-pot refrigerator! I wonder how well this would work in relatively cooler climes (like Canada)?
Pots for Peace have come up with an innovative way to ensure that water is over 98% pure. See their Ceramic Water Filter Project for more information.
Back a couple of months I became motivated to design a cheap solar water still that could be econoically provided to refugees, natural disaster victims, and the like. During my information gathering phase, someone sent me a link to a product that was astoundingly similar to exactly what I was hoping to produce.
Watercone is a super-simple solar water still. It’s a two-piece plastic design that uses nothing but the sun’s energy to produce over a litre of distilled water per day (depending on location, season, etc.) from any source water. Simply fill the dish with source water, float the cone on top, and at the end of the day take off the cap, invert the cone, and collect the distilled water.
Please see the HPL Water section for more information on water.
Pretend once again you’re lost in the woods. You’ve already secured your source of water, you’re built your shelter, so now what do you need? Likely, you’d want a fire for warmth, security, cooking, or any combination thereof.
So you brought waterproof matches, right? No? Ah well, we can work around that...
CLUNK. The power just went out. Regardless of why, your electric lights may not be working for a long time now. But you don’t mind, because you’re prepared. What have you prepared with? I’ve thought of three sources of light that may provide illumination without any civil infrastructure in place, all quite different. They are:
Obviously, all of these rely on different sources of power to provide light. My questions are:
Tealights can be had for less than $5/100. Each is supposed to give about 10 hours of burn, so if your aim is to simply give you enough light to ensure you don’t bump into things, tealights give you a big bang for your buck.
Unfortunately, as lovely as they are, you’ll need at least two to be minimally functional in a moderately-sized room. One will allow you to see objects and avoid them, but that’s it. If you want to see more, you’ll need two or three. Distinguishing colours will be difficult without a whole bunch. Reading by them is extremely tricky, as by their placement their light tends to radiate up from a surface, instead of down like you’d need to read.
Worst-case scenario, then: you need to light 5 per night, for 3 hours. That means your bag of 100 tealights will last you about 60 days, or roughly two months. One bag of 100 (like the kind you get at Ikea) isn’t all that big, but when you need 6 bags per year, they start to take up room. Obviously, you could toss $100 worth in the corner of your garage and it will last you for three years, but if society’s crumbling you may want to store things other than tealights. And $100 in tealights is not portable.
The other issue with any sort of candle is that you need a source of flame, at least intense heat to light them. Lighters are small and last a long time, so you could horde a fistful of lighters along with your pile of tealights, and that would last you a long time.
My gut feeling is that tealights may be a good medium-term solution. Sure, have a few bags on hand and stock a couple of lighters, but if something happens that permanently disrupts the availability of electricity, you’ll at least have some time to figure out what else you can do.
A lamp could conceivably last forever, but uses two consumables: the fuel (alcohol or oil), and wicks. The fuel could be stocked, but it is also one material that you could make yourself.
Through the marvels of fermentation and distilling, it’s possible that with a bit of ingenuity you could supply yourself with enough alcohol to keep yourself in light, and maybe even have a little snort before bed. However, alcohol is derived from sugar or starch through fermentation, so you’d need a supply of fruit or vegetables (apples, corn, potatoes) to ferment.
Oil could be derived from animal fats, and I’ve used enough olive, corn, sunflower, and canola oil in my time to know that it’s available from beans, nuts, and vegetables. The process of actually extracting the oil from said sources ranges from the fairly easy to the mechanically intensive. You may also want to consider whether using edible sources for lighting oil isn’t just a waste of what could be food.
Wicks, on the other hand, should be pretty easy to make. Old cotton clothing that is worn through would make many wicks. One pair of old jeans could probably last you into the next decade. So, as long as you think you can get or make lamp fuel, or the raw materials with which to make it, a lamp or two might not be a bad choice.
LED lamps, once you have them, require nothing but sunlight. There are two ways of implementing LED lamps. One, you could buy a solar photovoltaic (PV) array, a battery storage system, and run the LEDs off of the battery, using the PV array to charge the battery. Of course, you’d have to run wires, maintain the battery, and install the array somewhere with lots of sunlight. The battery, however, could get you through a couple sunless days should the need arise.
The second method would be to buy those solar moonlights that are so popular in gardens and along walkways. They provide a decent amount of light, have their charging and storage system built-in, and are portable.
In either case, LEDs have a large initial cost, but are pretty much free, for a while. The solar moonlights use a pair of AA NiMH batteries to store their charge, but are only useful for about 600 cycles, or two years. After that you need new batteries, which are not inexpensive. A hardwired system in your house could use a much larger automotive battery that has a much longer cycle life, thereby giving you a longer life. By charging only on alternating days you would double its life by cycling it half as much, with only a slight reduction in life due to a deeper discharge. Using an array of such batteries would give you the most robust system, but that has other issues beyond the scope of this article.
I don’t see a cut-and-dry winner. Assuming one can afford, and knows how to build, the infrastructure needed within your home for solar LEDs, that might be a real winner. Tealights I would award with being the most immediate solution, as it would be super easy to have a bunch on-hand that would last you a while. Lamps, while they seem like the best idea of all, may take away valuable food sources in the quest of making more fuel once your fuel stock runs dry.
I guess there’s a good reason that people went to bed when it got dark before the advent of electric light. We may simply find that keeping our up-past-nightfall habits are too energy-intensive to keep without the benefit of electricity.