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Because I’ve been frequently critical of the half-baked notion of vertical farms, it seems only fair that I link to this article about high tech greenhouses that, at first blush, have a somewhat vertical farm-y feel to them.
Vertical farms, you may recall, represent the extreme of the local food movement: massive edifices sited in urban environments that use a combination of technologies, from water recycling to artificial sunlight, to feed a city’s population in a sustainable manner. Such farms are entirely hypothetical — and, I’ve argued, impractical, pointless, and even faintly ludicrous.
Say hello to the new $50-million complex in Ventura County, California:
> On a recent afternoon, [farmer Casey Houweling] was eager to show visitors clusters of plump, sweet tomatoes hanging overhead from vines that reach high into the rafters. This arrangement allows the farm’s 450 permanent employees to climb ladders to pick the fruit instead of stooping. The plants, which are fed individually through tubing that looks like intravenous hospital equipment, produce 20 times more fruit per acre than in conventional field production.
> Virtually nothing is wasted in this ecosystem. Workers have dug a four-acre pond to store rainwater and runoff. This water, along with condensation, is collected, filtered and recirculated back to each of the 20-acre greenhouses. That has cut water use to less than one-fifth of that required in conventional field cultivation. Fertilizer use has been reduced by half. There are no herbicides and almost no pesticides, and there is no dust.
> Five-acres of photovoltaic solar cells supply much of the electricity to run pumps and climate controls. Thermal systems collect solar heat and warehouse refrigeration exhaust to warm the greenhouses on cool evenings.
Cool! The system presently only makes sense for high-value crops that can justify the huge capital costs, but that cost disparity is shrinking as water, energy, and other inputs become more expensive.
Does this mean I was wrong to knock vertical farms? The answer is (surprise!) no. The article makes clear that the success of these high-tech farms, as with all farms, is exquisitely sensitive to input costs and food prices. It makes most sense to site them in California, because the sunny, temperate climate means more growing days and less need to spend energy on heating and cooling. And nothing about the new greenhouses addresses the sunlight issue that troubles multi-story designs.
In other words, technological advances may make future farms vastly more efficient, but these improvements won’t erase the comparative advantages of certain growing regions. This isn’t a problem; rather, it’s a good thing. Our farms will get better at producing food, our cities will get better at housing and moving people, and our environment will benefit.