Re: Jackson Browne & Solar?

[RuthWeiner@AOL.COM]

In a message dated 4/25/02 8:42:39 AM Mountain Daylight Time, rorthen@EARTHSCIENCES.NET writes:



> What are the environmental impacts associated with "intercepting" radiant
>
> energy normally incident on the earth's surface by a solar thermal
>
> absorption and photovoltaic device farm of sufficient size to power a
>
> population now supplied by your nuclear or fossil boiler of choice?  I'm not
>
> talking about the obvious aesthetic and land use commitment ones, but rather
>
> the long-term thermodynamic detriment associated with such a "shielding
>
> effect" at the earth's surface.  Is the shielding (or perhaps more correctly
>
> stated, diversion) effect a valid concern for long-term sustainability of
>
> the land?
>
>
> * Is there an analogous situation with wind farms?
>
>
> * What air quality concerns would exist when a photovoltaic array is
>
> vaporized by lightning?


This is just an opinion: it seems to me that the major environmental impact of the area needed is that the area covered by solar cells is then taken out of agricultural production.  If 3 MW takes 160 acres, 1000 MW about 50,000 acres.  Since we are really in the infancy of this kind of electric generation, it is possible that the efficiency could be doubled or even maybe tripled, reducing the needed acreage to about 18,000 acres.  The solar "farm" could have strategically placed lightning rods to minimize lightning damage.


It's not that it can't be done, but this is not a good use of solar energy.  Solar energy is best employed passively, for direct heating (space heating and hot water).  My old thermodynamics text by F. T. Wall pointed out that the most efficient use of energy is to match the temperature of the energy source to the temperature of the energy use.  Using electricity, especially thermally generated electricity, for space heating is very inefficient.  


I think wind farms can still be used as agricultural land.  I wonder what they  do to downwind rainfall and weather patterns.


Ruth Weiner, Ph. D.

ruthweiner@aol.com