While driving through southwest Kansas and the Oklahoma panhandle, I noticed that the horizon was brown — the air is as dingy and grim as the air in Los Angeles ever was. It is tinged with particulate pollution that at one time was part of one of the richest topsoil systems on the planet. Now our soil is floating on the breeze, not doing anyone any good.
It’s time to do something about it.
Back in the prairie days, before the plow reached the plains, there was grass to hold down the soil. Then came farmers and soon after came the dust bowl. When there wasn’t enough rain, crops withered and the desiccated soil was exposed to the wind. These days, the main reason we don’t have more dust bowls is irrigation. Mighty pumps draw water from below the surface and spray it on the crops. This is still not as effective at erosion control as the prairie grasses were, and the activities of farming just plain raise a lot of dust. Not much one can do about it.
Or is there? What if we could do something about the other element in a dust storm — the wind? Slow the wind down and the air won’t be able to carry as much particulate matter. If we can slow down the wind enough, we might even begin to accumulate soil from less-enlightened neighbors.
Oh, I hear you now: “Hold the phone, there, Sunshine! Slow down the wind?” Yeah, it sounds crazy, I know, but in fact we already have machines that slow down the wind, and as a special bonus they give us electricity. Yep, windmills are machines that take energy out of the air and turn it into juicy, useful, power. There are already wind farms popping up in Kansas, giant pylons standing in neat rows across the very fields that are losing topsoil to the wind.
The difficulty with the current setup is that the windmills are put way up in the air, where there is less interaction with ground winds. This is done on purpose, as the giant rotors’ primary purpose is electricity, not erosion control, and the wind is steadier up there. (Also, it makes sense to get those giant rotors up where they won’t be whacking into things.) For this job we’re going to need windmills closer to the ground, which probably means many smaller windmills. Since efficiency at generating electricity is no longer the top priority, we can put them closer together. Each will generate less electricity, but the rows of them will make a more effective windblock.
How much do windmills slow down the air? I’m not really sure, but I’ve heard about habitats being affected downwind from them. It’s all a matter of taking enough energy out of the system.
That might be enough to make a difference, but we can add a low-tech modification to our fields to deflect the wind up off the ground and into the whirling blades. Simple scoop-shaped fences, perhaps configured in V shapes, can funnel the air whooshing along the ground up and into the windmills. More electricity, even less soil erosion. I’m not sure, but it wouldn’t surprise me if the water needed for the crops was reduced as well. Less water per acre means more land can be irrigated, which means more food.
The fence system assumes that wind usually comes from the same general direction; I imagine that when the wind is blowing parallel to the fences they might do more harm than good. Judging by the way the wind farms are set up, I think the direction is pretty steady, however. The V-shaped fences may prove to be a hassle for the farmer; modern machinery likes straight lines and big circles. Perhaps the fences could be replaced by long rows of grape vines. They would be less efficient at deflecting the wind but they would provide a significant additional crop. Another type of food makes the farmer less vulnerable to crop-specific pests and to random market swings.
I picture the ideal field as having some of the giant turbines to slow down the air up above, with rows of closely-spaced windmills below to slow the surface wind. Air moving over the field would be slowed enough that it’s carrying capacity was reduced, and rather than picking up sediment would deposit some of what it was already carrying instead. Free dirt!
The cool thing about this get-poor-quick scheme is that while it may not have the same immediate return on investment of a traditional wind farm, the watts per acre will be pretty high. Assuming energy prices keep climbing, it could even pay for itself. Then, when the aquifer runs out and the dust bowl returns, maybe America will still be able to feed itself.
Jerry, I think that if you slowed the wind down at the elevations above the ground that the current wind turbines sit, you will automatically have slowed the wind down on the ground. I think those things are set so high so as to reduce the effects of ground turbulance caused by the rapid convection of air near the ground on hot sunny days.
Anyway, did you enjoy your drive through Kansas? I live in Butler County east of Wichita. They do not have to irrigate out here at all with an average of 35 inches of precipitation (we had 52 inches the year before last!). The main reason I like this part of the state is because it is green and grassy.
I enjoyed my drive very much. I must say that I like the eastern side of Kansas as well. Sorry I didn’t make it over to where you were. Next time I’ll plan better.
Unfortunately, this particular get-poor-quick scheme runs counter to current trends in Agribusiness. The wind-slowing effect of a windbreak extends a little over 30 times the height of the windbreak (two to five times the height on the upwind side, in the high-pressure zone, and up to 30 times the height on the downwind side, in the low-pressure zone). The actual amount of wind-speed reduction depends on density, which in this scheme is arbitrary — you can keep adding turbines of all sizes, down to pin-wheels running micro-generators, until you’ve achieved the desired density… but at some point you may reach the point that the array will never pay for itself. (Of course, why else do you call them get-poor-quick schemes?)
The problem is, the current trend in farming is for huge corporations to buy up all the small farms and create one mega-farm. Mega-farms are most efficiently “worked” (plowed, tilled, seeded, weeded, cultivated… all the implements you see being dragged around by tractors) by convoys of huge tractors running in parallel. The longer these convoys can run in straight lines, the incrementally better the profit margin. Money is lost whenever these convoys have to turn around at the end of the field and jockey back into formation.
Windbreaks get in the way of this jockeying, and thus cost money. Windbreaks of trees and shrubs were planted, in the wake of the Dust Bowl, to control wind erosion. But it’s become popular for farming corporations to cut them down to improve the bottom line.
You could argue that windbreaks of power-generating wind turbines would contribute profit to the agricorps, but that’s a radically different business that would have to be integrated into an established corporate culture — a tough sell.
I know you used grapes as an example, but they simply don’t work everywhere. My father tried multiple times to grow table grapes in La Junta, but alkaline soil and water defeated him every time. Besides, diversity isn’t profitable in the short term. Agricorps grow the minimum number of crops, minimizing their investment in equipment and training.
Wow – facts and numbers and stuff. Thanks, John!
Grapes I kind of pulled out of the air as I was typing. I wonder if farmers do different set-ups when harvesting those circular fields, or do they just go back and forth across multiple circles at once?
The economic viability of the plan does depend on generating enough electricity to offset the increased cost and slightly diminished yield of the farm. I don’t see anyone actually doing anything like this until water is substantially more expensive than it is now, which will likely be a sudden event. Still, ever-climbing energy costs might make this particular plan more attractive.
There’s also a natural resistance to change; agribusiness has developed methods that work plenty well enough in current conditions.
This idea may have been quarter-baked…
Not that I’m speaking out in support of corporate mega-farms. I’d prefer to see lots of smaller, family-owned farms, following sustainable agricultural practices. In this fantasy, farmers could band together in wind-power co-ops and connect all their power-generating windbreaks into local grids.