Sunday, May 16, 2010

Vertical Agriculture + Solar Access

It's been a bit since I've posted on Vertical Agriculture - but an architecture studio I'm helping with at Portland State has a number of students pursuing food production as part of their buildings relating to urban ecology - and has me again thinking of the practicality of these building-based growth modules. While intrigued by the concept, I want to see a more holistic concept of food production through cities - and also better information on these concepts and how they work.

:: Design by Greg Chung Whan Park - image via Yanko Design

It is no surprise have been somewhat critical of the implementation of these solutions - as they tend to be more style over substance - and many are not thinking about the practicalities of growing food in buildings. Mostly, they are impractical because we still have a lot of vacant and underused land, rooftops, and walls that make more sense to grow food before investing in these expensive installations. Case in point is this Fortune rendering from Detroit of a virtual amusement park of agriculture... in a city that has literally square miles of contiguous terrestrial land ready for cultivation.

:: Detroit Visions - image via Treehugger

All the practicality aside - as a thought exercise the implementation of vertical farming is a fascinating architectural problem - as just the ability to maximize solar access is key to providing the most growing surface area with access to quality light. This is typically accomplished with a series of terraced landings stepped back as the height grows, often augmented by glass enclosure to create a greenhouse like interior rooms on multiple levels.

:: Growing Power, Milwaukee - image via City Farmer

A lot of the solutions lack a simple understanding of solar access - something that at least should have been drummed into architects related to daylighting practices for passive solar design. While allowing access and bouncing diffuse light within building for people is one thing - the integration of quality solar access. How does the following building work in terms of maximizing productivity? As mentioned about 30% of the building space is taken with productivity through a combination of thin terraces and living walls - enough to feed 200 people for a year. Is it worth the investment?

:: Urban Farmway - image via City Farmer

Again back to solar access - it is a fundamental tenet of vertical farming to do extensive solar access studies - starting with the. Back to the proposal by Greg Chung Whan Park , a couple of simple diagrams show seasonal and daily movement of sun.

:: images via Yanko Design

One idea is the spiral, which takes advantage of the circular nature of solar access through a spherical form with spiraling layers of greenery. Overall An image here of the installation, along with a video showing off some of the key elements inside - which gives it a feeling of more machine than garden.

:: Plantagon Greenhouse - image via City Farmer

A more sectional view gives an indication of the amount of solar gain. Again, I think weighted towards the visual and less about the overall efficiency - as the single-purpose building is a lot of expense for what amounts to very little productive space.

:: image via Plantagon Blog

The machinic aspect of many of these proposals is evident in the design - sort of a form follows form approach that makes for striking (if somewhat ridiculous) architectural solutions, and names to boot. For a full survey of many of these check out the Vertical Farm Project website. Most notable in the wild solutions is Dragonfly by Vincent Callebaut is one of those examples, for instance derived from a thin form to maximize surface area - but somewhat dubious thinking as to the viability of the project. In this case, I'd say that the fact that the land area is spread thinly over a surface would mean that it would be difficult from a 'farming' standpoint to maintain this on a daily basis. Is it done by robots, as some concepts look at? Does it work? Can you build it? More important, what's the cost of produce grown in these, and does the energy required to build and maintain these structures outweigh the cost of more traditional agriculture?

:: image via Spiegel Online

All of these questions permeate my thinking as I see proposal after proposal. Even some of the proposals with diagrammatic study leave questions, like the Eco-Laboratory sections by Weber Thompson. The ability of orientation - in this case the entire facade for production, gives maximum potential solar gain. The shading mechanism seem to reduce the effectiveness, by limiting solar access at steep sun angles during summer, when the production potential is greatest. Perhaps a way to limit the amount of solar gain, it seems as if this would reduce overall productivity - or at least shift the building to more winter based, season extending work. While laudable to extend the season, shouldn't the configuration work on a 365 day basis?

:: image via Vertical Farm Project

The other variety is those cylindrical towers that give the idea of maximum access. In the case of the Living Skycraper by Blake Kuresek - the tower is wrapped in spiraling layers (similar to the Plantagon greenhouse). On one facade - let's say 1/2 of the cylinder, the solar gain will be great - it's unclear what's happening on the sides and back that is getting north light and less intense east and west light (I'm assuming Northern Hemisphere). The other aspect not mentioned specifically is what is grown in these various spaces - as the levels of light and amount of exposure - along with intensity and heat - will determine a continuum of what is more appropriate in different parts of the building.

:: image via Vertical Farm Project

This is but a cursory view of some ideas, but a good chance to take stock of the myriad solutions and evaluate them on their building-specific merits. Often information isn't available to have a true discussion, but when looking at these ideas (or designing them) a few trends emerge:

  1. How does the building configuration work with maximizing solar access, and how is this explained?
  2. Are there beneficial synergies utilized with growing food in building such as capture of waste heat, rainwater collection and storage, or tapping into waste water sources for irrigation?
  3. Is there specificity in form tied to the types of vegetables grown, and how does this fit the overall food needs of the location the project is planned? Is it generic or specific based on high-value foods or ones that benefit from the added cost of production?
  4. Is the building agricultural only or woven into another use?
  5. What is percentage of renderings to diagrams in the solution? (An informal indication of rigor)
  6. How is maintenance addressed in location, access, and size of growing plots?
Look forward to some additional posts on this, as I've got a lot of source material I'm sifting through, and will be able to tease out many more ideas based on the explosion of solutions in the past couple of years.

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