Re: (ET) Fwd: [EVDL] The Case for the Electric Tractor

[robert winfield <winfield100 yahoo com>]

I agree with Chris about thin film amorphous vs Poly
crystalline vs single crystal.

I have 32 BP amorphous 43wt PV panels @ 3.5%
efficiency after 8 years for 11% of my total yearly
electrical useage

they cover 298sq ft of roof

I could use 6 of the Sharp 185's that cover 60sq ft to
get the equvalent power out


--- Christopher Zach <cz alembic crystel com> wrote:

> David Roden wrote:
> > On 24 Aug 2007 at 15:11, Darryl McMahon wrote:
> > 
> >> solar panels are the most efficient way of
> converting
> >> radiant sunlight energy into electricity
> (approaching 20% vs 1% or
> >> much less for plants). 
> > 
> > Where do they get this number?  I think I've read
> that mass-produced PV is 
> > around 10% efficient at normal operating
> temperatures.  
> 
> It depends. Thin film is about 7% efficient,
> polycrystaline is around 
> 14%, single-crystal about 18%.
> 
> I have 1.8kw of single crystal Shell 75 watt panels
> on the house and 
> about 800 watts of Solarex polycrystaline on the
> shed. The Solarex 80 
> watt panel is *much* heaver and larger than the
> Siemens 75, and the one 
> thin film panel is bigger than both and only 43
> watts.
> 
> > I may have missed it, but they also don't seem to
> have figured battery 
> > amortization into the operating costs.  For road
> EVs, this is the largest 
> > contribution to per-mile expense, and I'd bet that
> this will also be true 
> > for an electric tractor in daily service.
> 
> Mmmm. Maybe. If you get 8 years out of a set of
> T105's, that's not 
> unusual for an Elec-trak with a stupid charger. How
> long does the 
> average B&S engine last these days (seems to be
> about 6-8 years)
> 
> Chris
> 
> 
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
>
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>