How can the mounting hardware cost as much as the panels? How do you work around it?

I've been trying to come up with the ultimate, optimal design for an energy efficient house. While location, climate, and desired architecture are all factors some designs are probably optimal if you simply focus on efficiency.

First, insulation :
These concrete geodesic domes with R-36 foam all around are probably close to the most efficient choice for structure available. Underground houses and ones built in dirt might be more efficient, but those are site-specific. (so are these, I suppose - got to get the locals to sign off on one). I'm thinking a house built from a single dome (a separate one for the garage) with a few sealed skylights. Most windows would be non-operable, conservative in size with careful placement, with double or triple paned glass. Built right, this place would be insulated significantly better than most freezers.

Well, if you start with one of these I'm wondering how to mount the PV array. None of the faces point precisely the same way. A second factor is that you need occasional access to the surface of the dome to repaint it, an every 5-7 year project. (one of the few maintainence tasks this type of structure needs, they are supposed to be maintainence free in most other respects).

Poles would work, but they are rather pricy. A 3000 square foot home would need at least 3 of these systems : http://sunelec.com/index.php?main_page=pv_systems&id=1050&type=GT

To mount all those panels on poles (the base of each pole would fit into a mount that would be either bolted to the dome or to the ground) would cost about $13,000. That's half the price of the rest of the system! It might actually be a better idea to buy more expensive and more efficient panels just to get the same output using fewer panels and/or expensive mountings.

At these prices, are sun trackers even worth bothering with? If the bare panels cost this much, I shudder to think of the cost (and maintainence requirements) of a big electric motor/sensor system to move the array every day.


Another thing I wonder about is how multiple systems fit in. For this "ultimate efficiency structure" it would use an indirect solar hot water system, fed by both a rooftop box with the piping AND a desuperheater off of a geothermal system. And what the heck, might as well add in a drain heat recovery system and use a gas fired on demand heater as the last stage of the heater. That's 4 different systems just to heat up water. The cost of each additional system might not be worth the dimishing payoff. Just a gas fired on demand heater boosts efficiency by ~19% compared to a tank system. Drain heat recovery supposedly recovers about 50% of the heat. At that point it's probably not worth the cost to add a solar system and the desuperheater.

Similar arguments apply as to whether it's worth it to use geothermal heat and A/C for a dome when heating and A/C demands are so low anyway. You'd need a smaller geothermal system for a dome than a conventional structure but there's fixed costs in drilling the wells for a system. (though the kind that use trenches are probably not too unreasonable in cost. A DIY kit is about 5 grand)

My thinking is unclear, here. Now that I look at these words, I realize that I'm not trying to envision the most energy efficient structure possible - I'm trying to factor in economics as well. Alas, if I think about it too much, I realize that the most energy efficient and economical structure is an apartment in a beehive. Shared walls, ceilings, floors - can't beat that reclaimed energy with fancy tech.