alt.energy.renewable

"Roland Mösl" wrote in message
news:cd20b$47047742$557f97f0$27118@ ...
> >> One squaremeter photovoltaic delivers enough fuel for
> >> a medium sized car for 1000 km a year.
>
> >boy, that just sounds, wrong.
>
> A medium sized car needs around 15 kWh/100km
>

Does it ? Where did you get this number ?
Very quick calculation :
Medium sized car at 30 miles/gallon uses about 83kWh gasoline energy per 100
km.
At 30% efficiency (about right for an average engine) that is 25kWh electric
per 100 km.
That is assuming electric motors run close to 100 % efficiency.

> This are 150 kWh for 1000 km.

250 kWh for 1000 km...

>
> Modern photovoltaic has up to 160 Watt peak per
> squaremeter.

16 % efficiency ?
Where did you get this number ?
Isn't it closer to about 8 % ?

>
> So it's right in Germany.
>
> When You live much more south than Germany,
> it's wrong. In southern California
> up to 1500 km per squaremeter and year

How did you get to that number ?
The 160 Watt peak per square meter is already assuming 1000 W solar radiance
at 16 % efficiency. Cannot get any more than that, no matter where you are
on the planet.
160 Watt peak with 150kWh per year you seem to assume about hours of
full sun per day. I have to assume that that is pretty average.

More realistic : 8 % efficient solar panels, 250kWh per 100 km, makes about
square meter panels for 1000 km per year. Assuming average drive of
15,000 km/year, that would require about 52 square meters of panels to run
an average car. 52 square meters panels is (at 8% efficiency) about costs
about $50,000.- installed. This as opposed to about $1000/year in gasoline
(at $3/gallon) to drive the same 15,000km/year.

I still like your calculations (expressing car power use in terms of square
meters of solar panel). But I think your numbers are a bit too optimistic.
You are a factor of 3 or 4 off.

>
> Compare the insane military budget of the US
> with some squaremeters photovoltaic to maintain
> mobility with cars.

$50,000/car. US military budget of about $100 billion /year could sustain 2
million cars/year. Not bad. Unfortunately, there are about 200 million cars
in the US. So US military budget could only sustain 1 % of solar panel
driven cars per year.. Still not bad, but it does put things in perspective.

>
>
> --
> Roland Mösl
> http://car. cars and traffic
> http://live. building and live
> http://www.
>
>
>