SolaRoof | Tunnel Greenhouse

Hobby Farm Experimental Greenhouse

I am interested in discussing the construction an operation of a "hobby farm" type of stand-alone tunnel solar greenhouse using the working greenhouse of Ross Elliott as a starting point. This would become a retirement project for me and would be an experimental project rather than a commercial project. Ideally, I would like the greenhouse to be relatively self-sustaining from an energy standpoint using small photovoltaic and small wind systems.

The goal would be to use the greenhouse for a self-contained aquaponics system (along the lines of systems developed and sold by Backyard Aquaponics of Perth Australia---(see www.backyardaquaponics.com/designs.htm ) using the yellow perch species as the fish of choice (since it is high quality, much in demand at high prices and can handle much lower temperatures during the Winter) ---see www.ftai.com/articles/GAA Manci Dec 00?.pdf

The greenhouse size I envision would use something like the 16' x 32' Solarstar Sidewall greenhouse kit(see www.gothicarchgreenhouses.com/solarstar.htm )as a base unit. The solaroof aspects would be added to this following the design used by Ross Elliott with input from Richard Nelson. Perhaps the design used by Ross could be improved based on his experience.

While I have read most of the material available from links on the Solaroof website, a number of issues concern me at this point: 1. The need for multiple mechancial devices (multiple water pumps, bubble generators) all of which are subject to temporary failure which would serious compromise the success of the green house if temporarily disrupted. This in turn implies that even a small greenhouse needs constant monitoring in cold weather even with automated process control devices in place. 2. The need for a large subterranean water storage tank for heat storage and side storage tanks to store the bubble solution. Assuming these were made of concrete from an excavated area, this could add considerably to the capital cost. Would buried poly tanks be a viable alternative? 3. The high cost of the bubble generators $8,000 for 2. Is 2 really enough? What if one fails on a cold winter night? 4. High humidity problems in Winter----how is this dealt with when the greenhouse is more or less sealed on cold Winter nights? Could provision be made for bringing in a constant supply of fresh 'earth tempered" air? See www.thenaturalhome.com/earthtube.htm for a discussion of this aspect. 5. Why has this technology not taken off? It appears so promising on paper. Is it too subject to mechanical failure? Several commercial ventures in the late 90's and early 2,000's in Alberta and Quebec have seem to come to naught. Why? What are the problems?

My sense is that the current high cost of energy is not going to go away but intensify. Therefore, this technology will become more and more viable with time if the bugs can be worked out.