Build a Geodesic Dome Solar Greenhouse to Grow Your Own Food

Click here to view the slide show and follow along.

Photo credit: Jim Dunn

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SLIDE 1

What do you do when you want to grow your own food, but live here? That's the question my dad wanted to answer when he started this project about a year ago: Living at 7,750 feet above sea level, with a summer growing season of 80 days, at best, between killing freezes, how can you grow your own food? The answer, as it turns out, is pretty cool: A geodesic dome solar greenhouse.

Click through to see what it's like to build one for yourself, and how the garden grows inside once you're done.

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SLIDE 2

Here's Dad's garden, prior to the greenhouse. It's on a south-facing slope, behind the house, which is good for sun, but the direct sunlight during the middle of the day caused a lot of wilting in the lettuce and spinach and such that he liked to grow there. Plus, the local elk, deer, and rabbits who frequent the backyard would also make short work of eating everything -- hence the elaborate and quasi-functional netting system over top. All of this, plus the short growing season, meant that these raised beds weren't really cutting it.

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SLIDE 3

After some research, Dad decided that a greenhouse would be a good way to extend the growing season, and that a geodesic dome would be a good shape to get the most out of the southern exposure (Bucky Fuller would probably agree) and maximize the solar energy from the 300 days of sun in Colorado. As it turns out, a company called Growing Spaces -- TreeHugger Sami spied them recently -- builds kits for just such a situation. So here's the proposed spot for the dome.

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SLIDE 4

The local Home Owners Association was quite interested in his plan, and not in a good way, unfortunately. After several rounds of proposals, some less-than-polite exchanges, and a few compromises -- the trees on the left side of the photo had to be added, to help the dome "blend in," for example -- the HOA bought it and he was allowed to break ground.

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SLIDE 5

The proposed spot is on a bit of a slope, so some excavation was required to flatten it out. The extra soil, piled off to the side, was saved to be added to the beds inside the greenhouse, upon completion.

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SLIDE 6

A layer of rodent wire goes down before the foundation, to help keep any unsavory characters from tunneling up into the warmth and potential food supply that'll soon be inside the domed walls.

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SLIDE 7

A dump truck arrived with a load of gravel that was to become the foundation for the structure. Though the domes can be built on anything from a poured concrete foundation to a flattened patch of dirt, Dad chose gravel because it was easy to move, work with, level, and it drains well.

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SLIDE 8

The laser level came out to get the foundation flat and level. As with most construction, it's important to get it level; since this is essentially a prefab kit, it's especially so: An unlevel surface would put undue stress on one part of the structure that's designed to sit on a level surface.

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SLIDE 9

With all that complete, it was time, finally, to start the actual construction. The dome from Growing Spaces comes pretty much as a prefab, so the on-site construction is sort of like an advanced version of Legos, consisting of mostly following the directions and bolting things together. Dad was able to do the outer walls, shown here, by himself.

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SLIDE 10

Now the dome is really taking shape. Bolting the dome's structure together takes four hands, for a bit, but, with some help from my mom, Dad was able to get from the leveled foundation to this skeletal structure in three days' time.

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SLIDE 11

For the first time, the dome actually looks like what it's supposed to when it's finished. This illustration highlights some of the finer points of the design.

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SLIDE 12

Dad was starting to get tired of doing all the work himself, so, thankfully, his brother and sister-in-law showed up to help put the first glazing on. This was the first part that he really couldn't do by himself.


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SLIDE 13

One of the benefits of the dome architecture is that it's extremely strong, especially considering the construction materials used. That's me up on top, helping put the finishing touches on the outside structure so it'd be weatherproof when it started to snow.

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SLIDE 14

With the outside buttoned up and ready for winter, Dad was able to start with the inside work: Building the perimeter and interior growing beds; installing the water tank for thermal mass; wiring a variety of solar gadgets and other operations needs, like the ventilation fans. Right now, though, it's mostly just a pile of stuff on the ground.

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SLIDE 15

His buddy Paul came by to help install the thermal mass water tank; at 600 gallons, it provides a substantial amount of thermal mass -- it absorbs heat during the day and radiates it out at night, keeping the interior of the greenhouse at a warmer and more constant temperature. It's on the north-facing side of the dome, beneath the shiny stuff, which is called Reflectix, a brand of aluminum-coated insulation/heat reflector that covers about 20 percent of the interior. It's an optional feature, and can just be stapled to the inside of the glazing.

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SLIDE 16

The perimeter beds go about three-quarters of the way around the interior wall of the dome -- the last quarter or so is where the thermal mass water tank sits. Dad sited it so that the perimeter beds are on the south-facing side of the dome, to best take advantage of the sun's position and solar energy.

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SLIDE 17

With the perimeter beds in, it's time to install the interior growing bed. This is a good shot of the undersoil heat pipes that live under each growing bed, helping regulate the soil temperature for optimal growing conditions. And I think he got his tools out of there first...

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SLIDE 18

Everything is installed, and it's ready for planting. This is early February, just over three months from when he broke ground. The box on the interior growing bed is the air intake for the heat pipes; a fan in the box, wired directly to a small solar panel on top of the greenhouse, blows the warm interior air down into the pipes to help keep the soil temperature up.

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SLIDE 19

In the meantime, a pretty typical Colorado winter was dumping snow outside. This photo was taken on March 28, and it would be months until he could have planted anything outside...

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SLIDE 20

...Yet the greenhouse was looking like Spring. Some spinach and chard are growing comfortably in the perimeter beds. This photo was taken on the same day as the previous slide, with all the snow outside.

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SLIDE 21

As it gets warmer, the vents on the side help regulate the temperature inside. Just like anywhere, too much heat or humidity inside the dome isn't good for growing, so these vents are an important part of the efficient growth inside the dome.

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SLIDE 22

Here's Dad's data collection setup: The data logger on top tracks temperature, humidity, and the sun's intensity, and reports it to Dad's computer; the thermometer on the bottom is a good indication of how efficient the greenhouse is -- it's not quite 48 degrees outside, but a balmy 62 inside, even before the sun gets high in the sky, at 10am.

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SLIDE 23

This data logger report shows a fairly typical day in May in the greenhouse; the blue line is relative humidity; green is light intensity; dotted black is soil temperature; and solid black is the greenhouse's interior temperature. It's easy to see how the system works together -- water as thermal mass, air vents regulating air temperature, and so forth -- to create a more optimal growing environment than the outdoors would provide by itself.

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SLIDE 24

Fast forward to June, and you can see how well it works. The greenhouse is nearly overgrown with squash, gourds, and carrots in the interior beds, and tomatoes, green beans, and a bunch of other green goodies in the perimeter beds.

The greenhouse has been working so well that it's produced way, way more food than my parents can eat themselves, so Dad makes regular deliveries to my sisters (who live nearby) and the neighbors, who are happy to be just about the only residents in town eating lettuce, spinach, and carrots that don't come from eastern Colorado or California.


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SLIDE 25

The greenhouse garden hasn't been without a few hiccups, though. Aphids and a few other pests found the bounty inside the dome earlier this Spring, and did some pretty significant damage. Not wanting to hose the plants down with pesticides, Dad called in a cavalry of ladybugs, who seemed to really appreciate the large food supply, and are now happy full-time residents.

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SLIDE 26

All in all, Dad's biggest "complaint," after a season and a half of growing, is that the plants have done too well. He's used to a marginal success rate when it comes to growing -- the animals, climate, and weather see to that -- that is not really a problem with the greenhouse. Going forward, he'll adjust when and what he plants so that it isn't quite so overgrown, so that the plants inside have a little more room to spread out.

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SLIDE 27

All in all, it's been an overwhelming success, as he plans to go from roughly 80 days of growing season to more like 10 months; he hopes to go until the end of November this year, and will plant again next year early in February.

More about growing your own food
- How to Go Green: Gardening
- Greener Gardening: Why Grow-it-Yourself Organic Food is Here to Stay and How to Get on the Bandwagon
- TreeHugger Picks: Grow Your Own Food
- Quiz: How Green is Your Garden?

Ice-ocean processes over the continental shelf of the southern Weddell Sea, Antarctica: A review

Keith W. Nicholls

British Antarctic Survey, Cambridge, UK

Svein Østerhus

Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway

Keith Makinson

British Antarctic Survey, Cambridge, UK

Tor Gammelsrød

Geofysisk Institutt, University of Bergen, Bergen, Norway

Department of Arctic Geophysics, University Centre in Svalbard, Longyearbyen, Norway

Eberhard Fahrbach

Alfred-Wegener-Institut für Polar und Meeresforschung, Bremerhaven, Germany

AGU.org

Interactions between the Southern Ocean and the Weddell Sea ice shelves are important both to the Antarctic Ice Sheet and to the production of globally significant water masses. Here we review the interaction between the Filchner-Ronne Ice Shelf and the shelf sea in which it floats. The continental shelf processes leading to the production of Weddell Sea deep and bottom waters from the original off-shelf source waters are discussed, and a new view is offered of the initial production of High-Salinity Shelf Water. Data from ship-based measurements at the ice front, from glaciological methods, and from measurements made within the sub–ice shelf cavity itself are used to describe the pattern of flows beneath the ice shelf. We also consider the variability observed within the cavity from tidal to interannual time scales and finish with a discussion of future research priorities in the region.

Received 8 October 2007; accepted 27 March 2009; published 22 July 2009.

Citation: Nicholls, K. W., S. Østerhus, K. Makinson, T. Gammelsrød, and E. Fahrbach (2009), Ice-ocean processes over the continental shelf of the southern Weddell Sea, Antarctica: A review, Rev. Geophys., 47, RG3003, doi:10.1029/2007RG000250.