(As heard on the Survival Podcast)
Most often, the answer to that line is "In the dark!" However, that doesn't necessarily need to be so--not even if you're facing a long-term power outage, or you're one of those fortunate folks who are able to move out back of beyond and live the prepper's dream lifestyle of self-reliance.
While the concept of wood gasification is hardly new, (in WWII the Germans used a lot of wood gasification, although coal gas was produced in even larger quantities), the folks at Tactical Wood Gas have developed some very high tech, high output wood gasifiers that you can use to power a small engine for a virtually unlimited time--well, at least until you run out of lubricants, spare parts for the the thing or it or the gasifier simply wears out.
The significance of this is huge. In a bad situation, those with a high-wattage source of electricity are going to be far ahead of those without. In my recent brush with darkness, having just a 2 kilowatt generator meant that we kept the refrigerator and freezer cold (irony alert, in the middle of an ice storm), the blower on the wood stove going so that the entire house remained toasty warm (rather than just a room or two) and we had TV and movies to keep folks entertained (and if you don't think that's important, try making your family do without it sometime). We could also have ran lights, a hot plate, power tools, computers or any of the other goodies of modern life if we had needed to. Try doing that with AA batteries recharged with solar panels.
Tactical Wood Gas's Big Dragon unit can run a 6.5 HP engine--in the Honda EU generator line, that's roughly an EU3000, one size up from mine. Are your mental wheels starting to turn yet? If you do some prior planning, you can do a lot with 3000 watts. Considering an EU generator is quiet to start with, a little "sound engineering work" will allow you to quiet one down to a whisper--very important if things happen to go all Mad Max on us.
While the $1000 price tag may seem a bit steep, with all the engineering done for you, all the parts tracked down and supplied, I suspect most of us would be hard pressed to duplicate it and have as efficient a unit for that price. Just looking at the size holes that need to be cut, a decent set of metal cutting hole saws will set you back a substantial part of that sum.
Looking at it from another angle, try to buy 3000 watts of solar panels, mounts, inverter, batteries and so on for that price. Don't think it will happen any time soon.
While it isn't going to be for everyone (for example, if you live in a high desert environment, this wouldn't be worth much since you'd have no wood to gasify), for a lot of the prepping class, this would make a lot of sense at a certain point in their career. It's worth the bookmark, just in case.