sci.energy

Don W wrote:
...
> There can only be one logical explanation for solar PV amounting to an
> insignificant portion of the energy supply.
...
> It's because building and installing enough solar PV to make even a minor
> contribution to the energy supply is a foolish allocation of resources.

It's because solar PV is currently very expensive. Pure and simple.

It has nothing to do with how much energy a solar PV panel produces
compared to how much it took to make (energy payback period). It
certainly has nothing to do with how much it cost to produce all the
PV panels ever made compared to the price of the electricity they
have all made up to this point in time. (Don Lancasters net energy).

I don't think PV panels will remain expensive forever. PV technology
is still developing and the price has been decreasing. Todays low
price is $3/watt. Next year outfits like Nanosolar may be selling
at $1/watt. Perhaps it'll become cheaper than that in a few years.

How cheap would PV have to be for the big utilities to get involved?

Say a single watt of PV lasts 25 years (it's warranty period) and
is put on the grid in the southwest United States on a tracker.
According to NRELs PVWATTS calculator it's estimated to put on the
grid some 2346 watt-hours/year or kWh over 25 years.

/solar/codes_algs/PVWATTS/

Say they sell electricity at 10 cents/kWh for a 25 year total of
$. Let's say the utility wants twice their money back at the
end of the 25 year period. This means the total system can't cost
more than ($/2) $/watt. Let's say the inverter/tracker
and rest of the system costs $2/watt (not unreasonable). The PV
itself would have to cost $.93 or less.

It sounds like $1/watt is the price where utilities will find it
profitable to start investing in PV in a big way.

Then again, prices in many areas are already 15 cents/kWh and
could be expected to more than double in 25 years. At an average
price of 23 cents/kWh the 25 year total becomes $ and the
PV could be as much as $/watt and they'll still double their
money.

Anthony
--
This is, of course, a vastly oversimplified and 'back of the napkin'
analysis. Better numbers are available at a reasonable cost.