Buildings in cities have lots of vertical surface area, but relatively little horizontal surface area (roof area).
Therefor, it's likely that the best place to place a solar collector, would be on the side of a building.
That might be fine for hot water and heating, but not necessarily for power.
That's because to generate solar thermal power, some distance is needed between the reflector(s) and the collector.
This solution is easy if you have access to two buildings. Specifically, build solar reflectors on one the south facing wall of one building, and a solar collector on the north facing wall of a building to the south of the first one.
To reduce loss of light for the building on which the reflectors are built, the concentrators could be made from dielectric mirrors which allow visible light to pass through, but reflect ultraviolet and infrared.-- goldbb, Jul 07 2009 Boiling Fountain Skyscraper Sculpture Boiling_20fountain_...scraper_20sculptureSimilar concept, but in the interest of art, religion and gratuitous danger. [bungston, Jul 08 2009] French Solar Collector http://en.wikipedia...solaire_odeillo.jpgThere are others, but this is the coolest, er... hottest. [neutrinos_shadow, Jul 08 2009] :( second bit of "deja posting" I've gotten today... can't find it though. Maybe this is me posting from the future.-- FlyingToaster, Jul 07 2009 [FT], what will next week's weather be like?-- swimswim, Jul 07 2009 If you''re in Manchester, same as always - "Rain. More rain later"-- 8th of 7, Jul 07 2009 Not bad. Cheaper than coating an entire skyscraper with PV materials, that's for sure. And if the mirrors are angled correctly, they would be equivalent in collection area to the entire shadow of the building on the ground.-- BunsenHoneydew, Jul 08 2009 We could call it: bake a pedestrian.
el dueno-- el dueno, Jul 08 2009 Proving the theory that everything was invented by someone French, see link for (sort of) this, but not really... well, it is two buildings, but they were designed and built for this porpoise, rather than 'commercial building first, solar collector also'.-- neutrinos_shadow, Jul 08 2009 The solaire odeillo is very cool, but not only are the buildings not "commercial buildings first," but they aren't commercial buildings, at all -- they're solar power research buildings.
Furthermore, it's clear from the linked image that the mirrors are perfectly ordinary focussing mirrors, reflecting all colors of light (you can see the reflection of the landscape in them).
If they were "hot mirrors," then in an ordinary photograph, the mirrors would appear to be clear glass, showing the surface of the building they were mounted on.-- goldbb, Jul 08 2009 To adjust for the sun's movement, you'd need to either move the mirrors, or the receptor (not as good, true focus is only achieved for one point in an unmoving mirror array). If you move the mirrors (windows) this might be just as, or even more complicated than coating the building in PV-cells. If you move the receptor, you have no means of shutting off the array, so a problem in moving the receptor means cooking the building it's mounted on. On the other hand, it would be paradise, with roasted birds falling from the sky, and streams of milk and honey all around (purchaseable add-on feature)-- loonquawl, Jul 10 2009 Dunno about you, but I was assuming tracking mirrors from the beginning. The amount of energy required to move them is miniscule compared to the energy gained- that's why even PV installations use tracking panels sometimes.
This could easily be retrofitted to existing towers too, as sunshading. For starters, that's going to save you a fortune on cooling. Doesn't even need expensive curved mirrors- flat is fine, as long as the receiving surface is the same size as the individual mirrors. Stick the hot spot and gen plant up on the roof of another tower.
In fact, I wonder if you could use electrostatically driven mirrors, like in DLP systems. Slice up some mylar, print conductive ink circuitry onto a plastic backing sheet, heat bond them together, and run it off by the meter.
Can you imagine how much power downtown Dallas, Texas could pump out? This is looking more and more like a stroke of genius.-- BunsenHoneydew, Jul 11 2009 random, halfbakery