A few days ago, I had dinner with the President of Sky Vegetables, a small start-up that aims to build greenhouses on supermarket roofs. Their environmental and economic business model is very attractive:
- Hyper-local sourcing means that customers can buy veggies grown by the "rooftop guys." Transport costs (cash and carbon footprint) are nil.
- Rent is not only cheap, but the rooftop garden will protect the roof, extending its life. (The installations use hydroponics -- not soil -- so they are not that heavy.)
- Water consumption is low, since water is pumped (solar?) from tanks holding fish to the roof, where plants -- fertilized with fish poop -- filter the water before it returns to the fish tanks.
- Best of all, veggies are VERY fresh.
Bottom Line: The high price of fuel -- an input to fertilizer and transport -- has changed the scale economies of agriculture, making mass production less attractive than local production.
6 comments:
Hydroponics..."not heavy"? Most soil have a mass roughly that of water, which is the medium of hydroponics.
water is heavy and most buildings are not snow load ready for lots of additional weight. with the lightest mediums, you will have at least 25 lbs/ sq ft. more likely closer to 40-60 if you actually want to grow more than seedum and ground cover.
a look at sky vegetables site leads only to one building- from rooftop gardening source's site- on a school in the bronx. i have been there- it is nice, but is possible due to the buildings there being built to handle a snow load of 70lbs/ sq ft.
buildings are not built that way out here. new construction is a different story, and the greenhouse picture on sky garden's site is only possible with new construction or a lot of reinforcement. a greenhouse is very heavy.
i believe strongly in the growing of food very close to the distribution site. this is a great idea. as i said on the train, in nyc we wanted to do the same thing and one big perk is the constantly running refridgeration that condenses water out of the air for a pure water source. we know that tap water for extended periods of time is not ideal for plants.
maybe the folks at sky vegetables and myself should get together and figure out how to make this work.
Fish poop alone...hard to believe... every hydroponic greenhouse I've visited or heard of are little more than a chemistry laboratory with the end result being a product that resembles a vegetable. The ones that sprang up here and in Colorado eventually went out of business and required huge tax payer dollars to set them up. Not sure exactly what the problem was, one extension agent said it was all just a scam by Dutch greenhouse
companies...??
Good Idea. Horrible implementation.
Sky vegetables is a pipe-dream. There is NO WAY that they can produce a "supermarket" volume of produce based on the floor plan of the their physical markets. It is impossible. Even they know it. They might supplement it, but they could never supply it (in that space, for a competitive price).
check out this link:
http://www.hydroponics.com.au/php/viewtopic.php?p=333
This critical discussion published in Hydropoinc Greenhouses magazine has a section regarding rooftop applications of this kind.
The authors seems not only much more credible but actually have the scientific background and experience to speak with authority about such things.
Keith Agoda has ZERO education and experience in food production systems. Also, his ground-breaking idea is old hack, its just new to the USA. Ideas are easy, reality is much harder.
I recently came across your blog and have been reading along. I thought I would leave my first comment. I don't know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.
Ruth
http://fendisite.com
Post a Comment