Archive for February, 2009

Building Materials Certifications

February 28th, 2009 by Seldom

We have FSC for wood, but what about the remaining building materials?

There are no requirements or incentives of any kind that a purveyor of steel, aluminum,
concrete, plastic, glass, bamboo, or any material other than wood demonstrate environmental
and social responsibility in management or resource extraction, despite the fact that substantial
environmental and social impacts are associated with production of all of these materials.

It is now time to begin moving toward certification of all materials used in construction. The
responsibility for initiating such change lies squarely with the leaders of green building
programs, executives of the largest building materials distributors, environmental
organizations, and environmentally concerned citizens.

:: Certification of Building Materials: Important or Not?

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How Many Gallons of Fuel Does it Take to Go 350 Miles?

February 27th, 2009 by Seldom

:: Flowing Data

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PV Under $1 per Watt

February 27th, 2009 by Seldom

First Solar announced that they have reached $1/watt for solar panels, within spitting distance of grid parity.

First Solar’s eventual goal is “grid parity,” a phrase that refers to making solar power cost the same as competing conventional power sources without subsidies. Right now the cost of making panels accounts for a little less than half the total cost of installation. The company estimates that it needs to get manufacturing costs down to $0.65 to $0.70 per watt, and other installation costs down to $1 a watt in order to reach grid parity—goals First Solar plans to reach by 2012.

The question, though, is whether First Solar or any other solar manufacturer would be able to handle the flood of orders that would ensue if they reached competitive cost. At that point, it comes down to a matter of having enough of raw materials. That is where the real limitations come to bear, according to a paper that will appear in the March issue of the journal Environmental Science & Technology. In the paper, Wadia and colleagues Paul Alivisatos and Daniel Kammen evaluated the global supplies and extraction costs for 23 promising photovoltaic semiconductor materials and found that the three materials that currently dominate the market—silicon, CdTe and another thin-film technology based on copper indium gallium selenide (CIGS)—all have limitations when ordered in mass. While silicon is the second-most abundant element in the Earth’s crust, it requires enormous amounts of energy to convert into a usable crystalline form. This is a fundamental thermodynamic barrier that will keep silicon costs comparatively high. Both CIGS and First Solar’s CdTe rank poorly in abundance and extraction cost, with CdTe ranking dead last in long-term potential based on current annual extraction rates.

Nanosolar also said they were able to produce their panels for $1/watt when they debuted last year.

:: Popular Mechanics

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Permaflow P-Trap

February 26th, 2009 by Seldom

$45 vs about $5 for a standard PVC P-trap.

PF Waterworks

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Insulation Relative Cost per R Value

February 25th, 2009 by Seldom

From the Superinsulated Home Book, 1985:

The relative prices should still be close.

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Concrete Components

February 24th, 2009 by Seldom

:: cement.org

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Concrete Countertops

February 24th, 2009 by Seldom

There are some good pictures in here.

Find more photos like this on Concrete Countertop Forums

Blueconcrete.com
has a lot of information.

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The last run of logo variations

February 24th, 2009 by admin

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Effect of Moisture on Straw Bale Wall R Value

February 23rd, 2009 by Seldom

This explanation of the wide range of R values found for straw bales makes sense to me. Dry bales have a higher R value than wet ones because a lot of the heat transferred to a straw bale with a high moisture content is used to evaporate the moisture.

:: Straw Bale: What’s the R Value

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Low Mass Sunspace

February 21st, 2009 by Seldom

A low mass sunspace is meant to serve as a heater, not a greenhouse for plants or a comfortable place for humans.

William A. Shurcliff:

It is hard to think of any other system that supplies so much heat at such low cost…

One could shorten the warm-up time of the enclosure and increase
the amount of heat delivered to the rooms by making the enclosure
virtually massless–by greatly reducing its dynamic thermal capacity.

This can be done by spreading a 2-inch-thick layer of lightweight
insulation on the floor and north wall of the enclosure and then
installing a thin black sheet over the insulation. Then, practically
no heat is delivered to the massive components of floor or wall;
practically all of the heat is promptly transferred to the air.

And since the thermal capacity of the 100 or 200 lb. of air in
the room is equal to that of one fourth as great a mass of water
(about 25 to 50 lb. of water), the air will heat up very rapidly.
I estimate that its temperature will rise about 40 F. degrees in
about two minutes, after the sun comes out from behind a heavy cloud cover.

At the end of the day, little heat will be “left on base” in the
collector floor or north wall and, accordingly, the enclosure will
cool off very rapidly.

New Inventions in Low Cost Solar Heating–
100 Daring Schemes Tried and Untried
Brick House Publishing, 1979

This works well with airflow between the sunspace and living space
during the day and no airflow at night.

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