Edge of the Outback

What is a seawater greenhouse?

(A General Description)
First and foremost, it is the intellectual property of Seawater Greenhouse Ltd., a London-based company founded by the seawater greenhouse inventor, Charlie Paton. Whatever I say about seawater greenhouses is nothing more than what you could learn should you become curious and peruse the web. With that said, let us go on to the meat of the matter.

The seawater greenhouse is as its name might imply: a greenhouse that uses seawater. It is highly energy efficient, and the only energy demands that are not met passively are from: 1) water pumps, 2) fans, and 3) monitoring equipment. Water is distilled by the sun, the greenhouse is kept cool by evaporative cooling, water is collected by a water-cooled condenser for irrigation, and the plants require less irrigation due to optimal internal humidity and temperatures. Air that leaves the greenhouse is cool and moist relative to the external air, and can be circulated through an outside growing area to improve growing conditions for crops there planted.

The greenhouse is built of aluminum, polyethylene plastic, and a cardboard-like composite. Pipes, the greenhouse cover, and the condenser are made of polyethylene; the frame is aluminum; the evaporators are a cardboard-like composite. That’s it. The fans and monitoring equipment require other metal components, and whatever generates the greenhouse’s power will not be so simple, but overall, the greenhouse construction materials are cheap, recyclable, and easy to work with. All things considered, seawater greenhouses are not just competitive with but they are much cheaper than any other greenhouse in hot coastal desert regions.

A greenhouse’s optimized design can be determined by a modeling program called Waterworks. Waterworks takes into account upwards of ten different conditions (humidity inside and outside, temperature inside and outside, wind speed outside… etc.) and produces an optimal greenhouse design. While the system is quite effective, some changes in design can be made to better suit a greenhouse to its specific location.

Seawater greenhouses work best in hot, arid, coastal regions near deep, cool waters, but these conditions are by no means limits. Personally, I think that the potential exists to break away from the coast entirely, but that is pure personal conjecture that remains to be proven. In any case, I believe it is safe to say that the seawater greenhouse demonstrates a high potential for versatility.

I’ll leave my description of the greenhouse at that: all the sources I got this from can be found online at the company’s website, either under the various posted subsections, or in any of the files from the “downloads” section. Read them yourself if you’ve the time and the interest, and learn more about the system for yourself. If you’ve my tastes, you will find it all quite intriguing!

My first photos will be posted soon; get very excited.