Posted by Bill on April 28, 2008, 7:22 am
I think Table 1 below provides strong evidence tar sands, oil wells,
biodiesel, electric utilities, and ethanol fuels should be abandoned
and we should go 100% solar. At least the government should require
all new housing to have 1000 square feet, or 50% of the foundation,
installed with photovoltaics. As for heat we could store summer heat
underground or in ponds, or transport heat from the mid-ocean ridges,
tropics, or across hemispheres via pipeline. Oil, coal, and nuclear
are a waste of time and money.
1. Energy per Acre per year (Gallons of Gasoline equivalent)
a. 17 watts per square foot (could potentially be 35 watts per square
foot with 40% efficient cells). 43,560 square feet in a acre. 5 sun-
hours a day (7 sun-hours a day in Inyokern California). 250 WHrs/mile
for a Prius. 30 miles in a gallon. Do the math you get 493 gallons of
equivalent gas in a DAY. In a year, you get 180,000 equivalent
gallons per acre. Furthermore, the panels can be put on building
roofs killing 2 birds with one stone. With all the black solar panels
covering a large area this may increase global warming. For fun I
decided to calculate using optimal conditions of 35 watts/ft2 cells
(40%) and located in inyokern.
b. For ethanol we produced 285 gallons per acre in 1995 using corn.
In 2004 we produced 385 gallons per acre. There are estimates by 2015
yield will be 600 gallons per acre. Furthermore there is cellulosic
ethanol with estimates as high as 1500-2000 gallons per acre
c. Actual production was 60 gallons for soybeans. In 2008, it is
pushing 100 gallons per acre. to a high of 150 for high yield
rapeseed. It should be noted the highest yield of biodiesel
comes from algae at 1000 gallons per acre or more. The diesel engine
comparing identical cars results in about 20-30% increased mileage.
d. If you install one 3.5 megawatt windmill on an acre, you will get
876,000 equivalent gallons per acre.
Posted by Tony Wesley on April 28, 2008, 3:22 pm
Do the math. From http://www.gizmag.com/sce-65-million-square-feet-solar-pa=
it costs 875 million dollars to build 65 million square feet of solar
panels. Tht's about $3.50 per square foot. At that rate, your
43,560 square feet is going to cost just under 600,000 dollars.
Posted by daestrom on April 28, 2008, 11:04 pm
But you can't scale up windmills at the rate of one per acre on a larger
site. They must be spread further apart than 1 per acre. Something like 1
per 40 acres. So your 876,000 gallons is created from a one-windmill,
40-acre site for an equivalent of only 21,900 gallons per acre.
Or go to a nuclear site like Nine Mile point (900 acres) with three plants
(621 MWe, 1135 MWe, 840 MWe with capacity factors of 80.1%, 83.9% and 94.4%)
for a generation of 21.8 GWhrs per acre in 2003. In your terms, that would
be 2,910,456 equivalent gallons per acre. (better than 100X what your wind
farm can do)
Posted by Kitep on April 29, 2008, 12:08 am
Your table lacks one really important stat - $/kwh.
Posted by Mauried on April 29, 2008, 1:09 am
On Mon, 28 Apr 2008 20:08:40 -0400, "Kitep"
Im still waiting to see a Base Load Solar Voltaic Plant in commercial
operation thats making power at night.