More Solar House Advances

Technocrat

More Solar House Advances

zogger

Fri Jun 01 22:18:29 -0700 2007

Science.

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One of the better venues to see out of the box thinking in solar home design is the annual Solar Decathlon. One of the entrants this year is from the University of Cincinnati, where they are incorporating some unique designs, including an evacuated tube solar thermal system which provides hot water or air conditioning and dehumidification.

.."In an attempt to maximize energy pulled from the sun, the use of evacuated tubes (“tubes within tubes” in which the innermost tube contains water) is proposed. These 120 tubes are actually used to form a patio fence on the south side of the house. When the sun hits the tubes and heats the water on the inside (even while the tube exteriors remain cool to the touch), it will produce enough energy to air condition the house and to produce all the home’s hot-water needs for washing, dishes, laundry, etc. The tubes’ hot water is then moved through a heat-exchange system where it would vaporize lithium bromide gas. The gas then moves into another chamber where it would become a cool liquid under high pressure that serves as something of an “aerosol can” that, when released from high pressure, would be used to create cold air to cool the house as necessary. The “battery” for storing all of this thermal energy consists of two cisterns (holding a collective 600 gallons of water) placed beneath the foundation of the house."..more there, images and a short video

More Solar House Advances

Charles E Hill

Sat Jun 02 07:43:05 -0700 2007
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In other solar news...

Scientists from Spectrolab, Inc., a subsidiary of Boeing, have recently published their research on the fabrication of solar cells that surpass the 40% efficiency milestone—the highest efficiency achieved for any photovoltaic device. Their results appear in a recent edition of Applied Physics Letters.

The Spectrolab group experimented with concentrator multijunction solar cells that use high intensities of sunlight, the equivalent of 100s of suns, concentrated by lenses or mirrors. Significantly, the multijunction cells can also use the broad range of wavelengths in sunlight much more efficiently than single-junction cells.

And for practical information on saving energy, including building your own basic heat-exchanger, I highly recommend Dr. Alan Zelicoff's book Saving Energy Without Derision. It is available from his website in PDF form for $10.

More Solar House Advances

Matt Fulkerson

Sat Jun 02 16:44:30 -0700 2007
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Thanks for the tip. I might be buying a house without A/C installed in Maryland. I'll check out Zelicoff's book.

rural DIY AC

zogger

Sat Jun 02 21:50:23 -0700 2007
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The last place we lived out in the sticks had a local country store that was airconditioned with the nearest creek! The guy took a junker window ac unit, and instead of pumping gas around, it just diverted cool creek water in and out, with the normal squirrel cage fan blowing in the cooled air. I noticed it one day when I saw a small line going down to the ground from the window unit, then walked over to the creek that direction it went and saw how he did it. It blew some pretty cool air, given it was a mountain stream.
I keep meaning to build something similar using our cold well water when we water the garden, but so far haven't found the appropriate roundtuit to get me motivated. But the theory is pretty simple and sound.