Debate Summary - SPS vs. Wind/Solar/Hydrogen

>
>>Man, I hate having to do the thinking for my opponent. Let me
>>explain the calculations for you. If the power is coming from the
>>SPS, then the utility doesn't have to maintain other baseload
>>generating capacity as it does with solar/wind. SPS IS BASELOAD
>>
>So what? solar/wind with hydrogen storage and fuel cells or turbines to
>convert hydrogen to electricity is also baseline capable -- as well as
>also being useful locally without a grid. So it is more flexible
>technology than the SPS+grid.
>
I've been working on some economic analyses of these issues. The major
problem is capital cost. The cheapest PV systems are roughly
$2500/kWpeak right now (price has dropped about a factor of about 4 in
the last 20 years). The cheapest energy storage system seems to be
large-scale compressed-air storage in deep salt mines (no that's not
local, but it's a heck of a lot cheaper than H2 generation and storage)
at about $100/kW-hour. For a base-load supply of 1 kW, even for PV
installations in the sunlit desert areas of the US southwest,
winter-time insolation requires provision of at least 5 kWpeak for 1 kW
steady (24x365); you also need roughly 20 hours of storage, so that all
adds up to about $15,000/kW (baseload). Today's best reversible fuel
cells for hydrogen production and utilization are at least $5000/kW.
Since they would have to run at about triple that power level in reverse
during the daytime, using H2 storage would at least double the total
capital cost to something on the order of $30,000/kW (baseload).

For an SSP solution, if the transmisison efficiency is equivalent to the
loss of solar energy in the atmosphere (25-30%), you only need 1 kWpeak
for 1 kW (baseload). Can space solar panels be as cheap as terrestrial
ones? Right now they seem to be on the order of 1000 times more
expensive which doesn't help - but production volume is very low, and I
don't see any fundamental reason they should be more expensive. Then,
additionally, you have launch costs, and costs for the transmission and
receiver systems. If we could get the PV cost to, say, $3000 and the
launch and other costs to no more than double that, that leaves us at
$6000/kW (baseload). That should beat terrestrial solar for baseload
power even with another decade's improvement in PV costs; however, we
would have to do even better than that (or have other subsidies or
motivators) to beat an expansion of nuclear power or some of the
proposed coal + carbon sequestration approaches.

Costs and losses in the electric grid are certainly issues, but much
smaller scale than these basic capital cost numbers.

Arthur