In my last post, a prime wheel-based architecture option entailed separating the complementary-sloped roof patterns of cube-based shelter and setting whatever was sculpted from them atop 3D rectilinear annexes appended to WPA’s south and north walls. Then it was suggested that although the equatorial-facing roof had limited area, it was still optimally oriented for a smaller scale solar system.
The reason I think it would be worthwhile to go for a smaller system is that I believe the common “all-or-nothing” mindset in replacing nuke, coal, or fracked gas power generation with renewables is a false choice.
As a semiconductor-based proposition, photo-voltaic electricity generation should have grown hand in hand with the escalation of electronic goods. However it did not, and its primary role was off the planet powering spacecraft for a long time. Even now, despite the rush of popularity in recent years, PV pitifully represents less than 1% of the electricity generating pie.
The situation can and should be righted by first scaling a PV system to the electricity needed for a home’s consumer electronics – computers, radios, stereos, TVs, etc., and lighting with the advent of light emitting diodes (LEDs). Such a system might be separate from grid electricity to avoid rate arguments and what not. Grid power would be utilized for motorized appliances like refrigerators, fans, washing machines, microwaves, etc.
Here’s an example of how a WBA porch roof would play out. For simplicity, the roof over a 7 X 12 porch at 30° latitude is sheathed by three 4 X 8 plywood sheets. In this area, one 4 X 8 PV panel is placed lengthwise such that 2 feet surround it on all sides.
This area might be characterized by substantial trim to soften the roof-as-appliance appearance, and/or be used for albedo compensation. To be mature and real about it, PV should admit its own heat contribution to both local warming (under the roof and inside the house) as well as global entropy and proceed accordingly. Happily the PV negative of waste heat production is easily neutralized by including sufficient white roof area around the panel.
The 32 square foot panel equates to about 600 watts. Next, a modest average of 3 hours of nearly direct sun per day is assumed for a total of 1800 daily watt-hours.
That’s a pretty nice chunk of a home’s power needs met by the panel. If the waste heat generated by the panel (9600 watt-hours) could be tapped for heating water – all the better. An added virtue of the WBA solar alternative is that more space is allowed for trees.
Such an approach would represent a good first step in giving the institution of utility monopolies some healthy competition. When I biked across North America to Alaska years ago, I found attacking the halfway points of hills where their maximum slopes lie was more effective both physically and psychologically than worrying about the top of the hill. I believe the same approach would work well with homegrown electricity generation.