Diesel fuel — Corn, soy, and flax seed oil.
You need a processing facility to get the ethanol or methanol out of these crops—how will you build one of these from scratch? What will you use to provide the energy to process the stuff?
Fertilizer—- Human and animal waste, food scraps, fish, compost from prior crops.
This approach was used during medieval times. It turns out that the nitrogen from these sources was nowhere near enough for the crops, much less for the current type of high-fertilizer crops. We could go back to a three-field rotation system… but how many of today’s farmers know how to make that system work?
You see, Chris, you are trapped in the organization man think-within-the-box view of the world. You come up with reasons things won’t work. Fortunately, there are always creative people who figure out how to make things work in spite of the obstacles.
No, I have learned a lot about older technologies and we moderns always underestimate just how complicated those technologies were and how dependent they were on other technologies. Even such apparently low-tech items as waterwheels required the coordination of enormous amounts of labor. Let me walk you through what goes into making a waterwheel.
First, you’ll need a woodsman to chop down the oak trees, trim them, and transport them from the forest to the worksite. You’ll also need a horse for the hauling, and all the grain and pasturage necessary for the horse. You’ll need several hundred feet of rope, which will require growing some hemp and getting a skilled workman (and a small amount of special equipment) to twist the hemp into lengths of rope. Oh, one other thing: you’ll need some miners to dig up the iron ore, a lot more trees for firewood, more workers to convert the firewood into charcoal (it’s tough to smelt iron ore with wood fuel—the energy density is too low.) Once the iron is smelted, you’ll need a blacksmith to make the axe for the woodsman as well as the other woodworking tools that will be needed. Oh, and for the leather for the horse’s tack, you’ll need tanners and somebody to gather acorns for the tannic acid, and somebody to leach the tannic acid out of the acorns. One other thing: you’ll need somebody to quarry a good piece of sandstone and shape it into a grindstone for sharpening the woodworking tools. And of course somebody else will have to build the grindstone housing.
Next you need some skilled workers to trim the wood into the constituent parts of the waterwheel. The outer sections will be fairly easy—just a lot of careful fitting and joining with hand tools. The really hard part comes in the center of the water wheel, which must be strong enough to bear the weight of the wheel even though it is pierced by the radial parts. This requires extremely tight tolerances in the placement of the holes as well as a very careful judgement of the ideal piece of wood. You can’t use iron here because it will quickly rust away in the wet environment. It will take a skilled woodworker a long time to get it good enough.
OK, now you’ve got your water wheel but you still haven’t mounted it. First you have to build a foundation on which to place it. This foundation will be part of some sort of damlike structure to route enough water into the water wheel. This foundation will probably be built out of rock and concrete. So you’re going to need quarrymen and stonecutters to get the rock and roughly shape it, as well as more horses and carts to move the rock from the quarry to the worksite. Also, you’re going to need a source of limestone that you can quarry (more quarrymen), and you’ll need to crush it (more workers), burn it (more workers and even more firewood), combine it with a pozzolan (ground pumice, brick or pottery) (lots more workers here), then heat it to drive out the CO2 (even more firewood, woodsmen, haulers, etc). You’ll need to set up a cofferdam to permit the workers to get down to bedrock—there goes even more wood, so you’ll need some more woodsmen, horses, and haulers. Once you’ve gotten the cofferdam in place, you can send your diggers in to clear out the right space for the foundations. Oh, you’ll need plenty of sturdy baskets to hoist the dirt and mud out of the work area, so you’ll need some wicker workers. And the diggers will need picks and shovels—more work for the blacksmith, and even more charcoal for his fire.
Now you’ve gotten the foundations laid and the main support structure built. You’ll need a bit more woodwork to get the mounting hardware and axle. All you have to do now is lift the waterwheel up and set it in place. Unfortunately, that’s not going to be easy. You’ll need a crane. That will require a number of long pieces of timber, quite sturdy and heavy. And lifting them up is a major problem in itself. The basic solution involves lots more lumber (hire more woodsmen) to set up a kind of scaffolding.
To actually lift the pieces and the waterwheel, you’ll need a big pulley capable of bearing the load. Your best bet is a carefully rounded round hunk of oak with a hole drilled through it. How are you going to drill such a hole? You get the blacksmith to make an awl and then you spend weeks digging down through the oak with the long awl. And you have to make sure that the hole is straight, so you have to build a jig to hold oak and awl. You’ll also need an axle for the pulley, but that shouldn’t be too hard; it might take only a few weeks to get it just right.
You’re just about there. Now all you need is a big gang of people to pull on the ropes to lift the water wheel into position. Then you secure the water wheel, remove the coffer dam (actually, it’s a bit of a trick to remove a coffer dam without getting killed in the process) and voila! You have a working water wheel generating perhaps one horsepower.
Consider all the people required to make this project work. You needed lots of woodsmen to get the tons of wood and firewood used in the project. You needed tanners, horses, carts (I never got around to talking about the people who have to make the carts), leather workers to make the tack for the horses, a blacksmith, miners, quarrymen, charcoal makers—- the project would have required the services of more than a hundred people. And not one of those people was growing food for himself, so with a 2% surplus rate, you would have needed 5,000 farm workers to provide the food for these people.
But wait—there’s more! You’re going to need to clothe and house all these people. The clothing will require roughly one woman for every two working men—add 2,500 women. I’ll give you the housing because that’s a long-term investment. You’ll also need cobblers to make the footwear for all these people… and what about the designers, organizers, police, and all the other bits and pieces of humanity we need to keep the social system operating?
When you add up all this, you end up needing a community of maybe 10,000 people to sustain the effort required to build a water wheel. And a water wheel is really low-tech! That’s my point: it takes a lot of people to provide all the bits and pieces that make up technology.