Hacker News new | past | comments | ask | show | jobs | submit login
Fruit Walls: Urban Farming in the 1600s (lowtechmagazine.com)
100 points by bootload on Jan 18, 2016 | hide | past | web | favorite | 11 comments

I find the Chinese greenhouses described in the follow up intriguing: http://www.lowtechmagazine.com/2015/12/reinventing-the-green...

This is a good era to revisit fruit walls because if you can make a robot that automatically cultivates and harvests the fruit walls, it makes them a viable urban agriculture option again because the primary issue with them today is the high labor input required.

The "if you can make a robot" problem for this use-case is quickly becoming "when you can make a robot" that. See, e.g., these (mostly) roboticized lettuce farms: http://www.fastcoexist.com/3050750/this-robot-run-indoor-far...

Interesting, I thought that one of the reasons for building greenhouses was that they trapped heat.

What I think is fascinating about this. Is that as humans we ignored opportunities to use the passive technology. For example, why don't today's greenhouses have brick floors or a brick north wall (even a small wall to increase the thermal mass)

In a labor-constrained setting, where the cost of labor is high, the cost of building the brick wall exceeds the recovery time period for most businesses. In a capital-constrained setting, where the cost of capital is high, the interest rate is often too high to repay the loan soon enough for small businesses.

Unfortunately, in most urban settings, both labor and capital are priced at a premium, so you get hit on both sides. When/where this was used, capital might have been constrained, but labor was generally not.

Capital, when taking on the form of land inflation, inflates the cost of labor, and often beyond direct energy costs. You end up with perverse incentives where quickly burning energy in the short-term will temporarily (for a lifetime or so) put you ahead of the economic game but put you quite substantially behind on overall energy sustainability if you start discriminating energy sources on generational EROI. I am beginning to wonder if The Great Filter is simply that galaxy-wide, any spacefaring-capable species wiped themselves out by economically exhausting all their high-grade energy before getting into any position in space where transferring much higher capacity high-grade energy from their sun was feasible.

Takes too long to recover costs? Requires larger footprint (shadow behind the wall unusable)?

The pessimist in me says "because these things would last centuries with a little upkeep, and we don't build that kind of thing anymore". Too hard to take advantage of short-term opportunities to repurpose or sell the land if you've put expensive, permanent(-ish) infrastructure on it.

> The pessimist in me says "because these things would last centuries with a little upkeep, and we don't build that kind of thing anymore".

They wouldn't. You're building miles of thick stone walls exposed to the elements, which you are deliberately forcing plants to cover as much of them as possible. The article and the followup hint at the repair and labor costs (note that the article is set in China):

> The decline of the European fruit wall started in the late nineteenth century. Maintaining a fruit wall was a labour-intensive work that required a lot of craftsmanship in pruning, thinning, removing leaves, etcetera. The extension of the railways favoured the import of produce from the south, which was less labour-intensive and thus cheaper to produce. Artificially heated glasshouses could also produce similar or larger yields with much less skilled labour involved.

This should not be surprising, since if fruit-walls were strictly superior, why were they ever obsolesced? In general, when reading sustainability fetish material like this, you should remember that these sorts of things are like code-golfing or min-maxing: schemes which place unrealistic value on just one dimension, and which can be highly interesting in how one maximizes that dimension, but are only rarely optimal under a more realistic set of tradeoffs. In this case, the fetish is for energy use while running, and mostly ignoring capital, repair, space, and labor costs.

That was with the materials back then.

Here are some of the current materials that we have that they didn't:

1. Concrete ( reinforced ) - much more durable than brick and mortar.

2. Mechanized vehicles like backhoes and the such to build walls

3. Better materials to trap and retain heat.

Probably others as well.

We also now have a global warming problem and other externalities that make greenhouses' energy inefficiency bad for society.

You know that "energy fetish"

I have some concepts integrating different ideas for sustainability which is related to this idea of fruit walls. In my concept, each group of residents has 1/3 of the property dedicated to insulated buildings that are full of agricultural production. They have large windows but are also supplemented with LED light. The materials and vegetation inside are the heat sink. I believe this is a more efficient way to produce food than a standard greenhouse because of the insulation and overall better temperature control.


> In the Netherlands, which is the world's largest producer of glasshouse grown crops, some 10,500 hectares of greenhouses used 120 petajoules (PJ) of natural gas in 2013

On a recent tour of hydroponic growers in Almeria, Spain, I was told that province alone had 30,000 hectares in commercial greenhouses.

Applications are open for YC Winter 2020

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact