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re: against renewable energy
31 may 1997
raul almquist loudly proclaims:
>(paul f. dietz) wrote:
>>(1) because of the low energy density of many renewables, they require
>>the use of large areas of land.
> partially true.
>
> pv farms do not have to be at ground level...
perhaps when you say "energy," you mean "electricity,"
a minor and shrinking part of our energy needs, imo.
>...flat roofs which have gardens on them would be exceptions...
good idea. flat roofs with food- and heat-producing greenhouses, even :-)
>>(2) low power density also means renewables require a great deal of material.
or, "low power density means renewable systems need to use a small amount of
material, comparable to the yearly value of the energy gathered, at today's
oil and gas prices."
> sorry. but again, the pv farms already exist.
pv farms. oh yes, electricity again, of which the price/kwh seems to be
dropping as deregulation and cogeneration catch on, and of which we can
so easily use less with cfs and more efficient appliances. but what about
space and water heating, which consumes 2-3 times more energy today, in most
us houses? (about the same in hawaii, about 5 times more in vermont.)
>...so the material argument is non-logical, unless you only apply it
>to ground level installations...
the more interesting material may be the pv cells themselves, if a 1-watt $5
cell (not counting installation labor and hardware, inverters, etc.) produces
4 watt-hours per day or 1.5 kwh/year worth 15 cents at today's electric rates,
for a simple return on investment of $5/0.15 = 33 years.
>...it just amazes me that such a statement could be used by anyone as any
>argument against hydroelectricity!!!
electricity again? that's a molehill. i thought we were talking about energy.
> sure i could make energy cheap, if i had subsidies and i was able to
>steal what i needed to make it available.
gee, maybe you should be in the pv business :-)
> sure renewable energy tech is expensive...
i disagree. renewable electricity is fairly expensive, but solar house heating
technology is over a hundred years old, and it can be very inexpensive these
days, using standard greenhouse hardware costing about $1/ft^2, returning on
the order of $1/ft^2/year of heat energy at today's oil and gas prices, as
well as adding floorspace to an attached house, unlike pvs or windmills.
this keeps improving with better techniques and materials, like bayer's
((412) 777-3837) very clear dureflex thermoplastic polyurethane greenhouse
film, which costs more than 5 cent/ft^2 greenhouse polyethylene film, at 36
cents per square foot, but comes in rolls up to 15' wide (for now) with a
10 year guarantee. it's been tested on greenhouses for 3 years now, and the
brochure says "the film has survived snow, ice, hurricanes and intense
ultraviolet rays. one greenhouse was destroyed by inclement weather except
for the dureflex film, which was reused once the greenhouse was rebuilt."
a user says "you can punch a hole in the film, and it has such good memory
that it closes back up to almost 100 percent."
> 1st get rid of all subsidies, especially those to mature energy
>technologies, make it a level playing field instead of an artifically
>mountainous one which has the preference for the mature energy technologies
>(technologies which should by then be paying 100% of their own ways).
sounds good. solar house heating is a mature technology.
greenhouse growers pay their own way...
gulf wars subsidize oil companies...
> 2nd, put into growing energy technologies all that $ which used to
>support the false pricing of the mature energy technologies...
you mean subsidize them? :-)
>to help get the growing energy technologies turn into mature technologies,
>then wait about 20 years and try your comparisons and see where it gets you.
i sense a guarded prediction. are you suggesting we subsidize pvs, a
technology over 60 years old, to make cheap pvs, "just around the corner,"
while still burning so much oil, and fighting expensive middle-east wars
to keep the street price of oil low?
nick
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