> Why pay for the energy to grow food when you can get the enegy for free by putting it out in the sun?
For many reasons: 1) Using vertical space rather than surface area; 2) Producing closer to population centers; 3) Producing year around irrespective of seasonal changes; 4) Not having to use pesticides.
1) and 2) are essentially irrelevant, because the fundamental limiting factor on both agriculture and sustainable energy generation is surface area. Plants are effectively photochemical solar arrays that turn light and CO2 into food energy; nobody would be crazy enough to propose a "vertical solar farm" where LEDs are used to illuminate photovoltaic panels, but vertical farms are exactly as bonkers.
> nobody would be crazy enough to propose a "vertical solar farm" where LEDs are used to illuminate photovoltaic panels, but vertical farms are exactly as bonkers
This isn't true: at least in theory, you can take white sunlight, produce electricity by the photovoltaic process and power LEDs in a spectrum optimized for plant growth (blue and red light instead of green). In practice the LED efficiency (150-200%) doesn't yet make up for the inefficiency of the best commercially available solar panels (25-30%), but the idea is not fundamentally ridiculous.
And solar power is not always the cheapest form of electricity, or even necessarily competitive. Consider Iceland, with abundant cheap renewable geothermal energy but a shortage of sunlight, and LED-illuminated farms make even more sense (and are already operating at scale).
1) and 2) round to “transport costs” economically and freight is cheap except in areas where people don’t have enough money to be worth selling to, like Afghanistan.
Carbon footprint of growing tomatoes in the wrong climate is like 4x higher than growing it in the right climate and transporting it.
Heating is one of the most power consuming activities in the world. The research has been done. The result can also be estimated numerically, carbon intensity of transport and of heating are well known.
In colder climates you must heat the greenhouse, which probably generates CO2. I say "probably" because a heat pump run on renewables is possible, but not likely.
Me too. Especially one accounting for all emissions end-to-end, and over a time frame of decades of use. While LEDs themselves are as dirty as the power source they're hooked up to[0], this doesn't count the energy used to produce and transport those LEDs and all other equipment. It's especially important because equipment breaks down, and a lot of it is designed to break down fast[1].
--
[0] - My mind races to imagine vertical or subterranean farms powered by a nuclear plant.
[1] - Also known as planned obsolescence. People are assholes.
1) I assure you that industrial LEDs are not 'designed to break down', their longevity is a key consideration for people buying them
2) What's the fetish with vertical farming? Productivity of a greenhouse is 10x to 100x of a conventional field. The key limitation is capital costs. Unless you are growing small plants like basil/strawberry, vertical farming doesn't make any sense. It balloons your CapEx, increases power consumption (sunlight) and you save land, which you have saved a lot of anyway just by going to greenhouse farming from normal fields.
Do most folks not appreciate that most of the farmland we have is open field, we are not running out of space for greenhouses?
RE 1), I didn't mean that LEDs themselves would break down (unless soldered badly). But their controllers, or power converters, just might. Like with LED lightbulbs - most of them break very quickly due to cheap power & control components and/or bad soldering job causing thermal damage.
RE 2), fair. In my mind, I grouped vertical and rooftop farming together, and find them desirable in the sense of bringing back more plant life into the cities (and reducing last-mile transportation footprint). But you're right, in terms of general food production, they're not all that interesting or useful.
There is no more energy efficient method of transport than oceanic freight. Rail freight is very efficient too and truck transport isn’t as good but it still beats growling locally in almost all cases in agriculture.
If you care about carbon footprint campaign for a carbon tax. Most of the carbon footprint of transportation is now and shall always be in the last mile, whether that’s Amazon delivering it to your door or you driving to Walmart or Whole Foods.
Capitalism is extremely good at reducing transport costs and since those costs are basically denominated in hydrocarbons it already does a better than half assed job of reducing carbon footprints. But a tax would be much better and more general.
> There is no more energy efficient method of transport than oceanic freight.
Yes. But no transport at all is more efficient than even the most efficient method of transport. And food doesn't get straight from the docks onto the tables. There's usually lots of trucking involved. As you also say below.
> If you care about carbon footprint campaign for a carbon tax.
I do.
> Capitalism is extremely good at reducing transport costs and since those costs are basically denominated in hydrocarbons it already does a better than half assed job of reducing carbon footprints.
Capitalism is also extremely good at making the costs disappear, and reappear elsewhere, usually very diffused and paid by people not being parties to the transaction. That's why I am an advocate of carbon taxing - because it puts those costs front-and-center.
Now I'm not against shipping food, and I recognize the oceanic freight efficiency. I have two reasons for being interested in "alternative", more localized farming techniques: one, the ecological footprint (not just carbon) that's not accounted for, and two, robustness. I have this feeling that with current systems, we're one or two big accidents from a large humanitarian crisis. I feel it would be better if smaller groups of people could meet their basic sustenance needs with local produce - and ability to grow anything anywhere would definitely help with the varieties available.
The ecological footprint argument is for greater industrial concentration and more efficiency. The US has returned farmland equal in area to Washington state to wilderness over the last twenty years because it became uneconomic to farm it. This while basically every measure of how much did the US produces goes up. This is part of a more general trend of doing more with less resources in the developed world. There’s a book on this More from Less , Andrew McAfee.
Robustness and efficiency are at odds with one another. Any highly robust system will be very wasteful indeed compared to an efficient one; any system with lots of slack just isn’t efficient. Obviously if you think a large decline in standards of living is an acceptable price to pay for that robustness that’s a political position you’re free to support but good luck getting the votes for it.
Ability to grow anything anywhere requires energy. If you’re assuming civilization hasn’t collapsed anyway these farms in a box are either solving a non-problem or one with limited applicability.
Fair. I'm a person who frequently comments here that centralized systems beat decentralized on efficiency, so I understand that point.
RE More from Less, I need to buy and read that book. I remember an article promoting it being discussed recently on HN, and from it I got a distinct impression that US "doing more from less" is just an artifact of not accounting for embodied energy and material waste during (outsourced) manufacturing. I.e. if copper imports go down and electronic components imports go up a bit and consumer electronics production go up even more, it doesn't mean the US is better at using less copper for consumer electronics; it means you're not accounting for copper China wasted manufacturing components.
Anyway, that's my initial impression; I'll have to read the book to see if it goes into any more details to support its conclusion.
There’s a recent episode of Econtalk that’s an interview with the author of you’re a podcast listener. If you put in the work to have an informed opinion please share it with the world somehow, whether in a review, a Twitter thread or an email to me.
>But no transport at all is more efficient than even the most efficient method of transport.
You can't make a general statement like that because it ignores the geographic advantages of the locations you are transporting from. If a certain location has a high concentration of copper for instance then its local abundance might be 1000x higher than the location you are transporting it to. Simply looking at the transportation cost doesn't capture the whole picture.
For many reasons: 1) Using vertical space rather than surface area; 2) Producing closer to population centers; 3) Producing year around irrespective of seasonal changes; 4) Not having to use pesticides.