Last year when we were still house hunting, one of my requirements (pretty much the only one, aside from having a sufficiently large yard to have a garden) was to have a southern exposure capable of building a lean-to style greenhouse/sunroom. A walk out basememt was preferred. Between those requirements and my wife's (post-1979 construction, updated kitchen/baths, main floor den, no pedophiles in a 5 mile radius, enclosed yard, close to shopping, priced under 70% of what I considered my budget, but value at 200%), and the Denver real estate market that shifted toward the sellers early last summer, it took us a full 9 months to find a house. The house we found is nice enough, good deal, good neighborhood, good condition, with almost a half acre on a cul-de-sac. It was a bit of a compromise, however in that not only does it not have a walk out basement, there is NO southern exposure. The front of the house is oriented toward the southeast, with NO basement windows on that side. While not ideal, there is one 4'x4' window on the the southwest side in a deep window well.

Pretty much the only requirements for an aquaponics set up are:

• power (for running pumps), and
• light (for, hello, growing plants)

I've discovered since moving in and attempting to germinate plants there, that the lighting from that window will be wholly inadequate for any substantial plant growing. This was not completely unanticipated, and allows for some needed engineering development in a tangential area of interest...

Consider that any off world habitat will likely be without the benefit of Earth's thick atmosphere and magnetosphere. The simplest solution to shielding from radiation in space is to put at least a meter of regolith between space and the habitat interior (ice would also work well, but for melting and sublimating under the sun's rays). Unfortunately, sunlight does not penetrate regolith any better than it penetrates my basement. So, if I can solve the problem for myself, perhaps there will be generations of grateful space colonists indebted to me.

Rather than immediately resorting to grow lights (still plan B), I'm implementing mirrors. Afterall, no grow light is as efficient as the sun (plants have, to-date, mostly evolved for sunlight), and any sustainable power generation in solar space must basically come from the sun anyway (interstellar space is another story). Photovoltaics are at best 30% efficient. Add in the losses of power storage and the lighting itself, and the mirrors start to become more and more appealing. Besides, Colorado is the sunniest state in the US; it'd be a shame not to put that to use.

Plan A:

1. Obtain mirrors
2. Orient mirrors
3. Expand window well
4. Reorient mirrors as needed
5. Build hothouse/greenhouse over window well
6. Reorient mirrors as needed

Plan B:

1. Install grow lights

The problem with mirrors is that the sun moves (relative to my window, for you astronomical nitpickers out there). I'm mainly going to want morning sunlight as it is best for thermal management (warms things up after being in the dark overnight), and it is the component I get the least of currently. For morning sun, I will need at least 3 mirrors (labeled 1, 2, and 3 in the diagram).

I have so far obtained most of the needed mirrors through my wife's garage saling efforts. I've placed them in approximate locations, with 1a and 1b hanging on my fence, 2 on the side of the house above ground, and 3 angled inside the window well. I've been casually observing reflections at various times, and it seems to be an improvement. Since the light will be much more critical in the winter months, and at a lower elevation in the sky, I haven't put much effort thus far into optimization.