SSPS for Hydrogen Economy

>
>> Here is an excerpt from Nature.Com:
>> http://www.nature.com/news/2004/041004/full/041004-13.html>
>
>> Can anyone calculate or guesstimate, or opine on how large of an
>> SSPS project would be required to achieve the same thing? Is this
>> a more palatable solution than 1,000 nuclear plants?
>
>Well, a nuke plant produces 7.9 billion KWh in one year - enough to
>supply electricity for 773,000 households.
>http://www.nei.org/
>
>Powersats produce more electricity the bigger they are, and the
>standard seems to be 5 GW. But what is that in KWh?

Back of the envelope: a GW is a billion Watts, or a million KW. There are 8760 hours in a year so one GW full time would produce 8760 Billion Watt Hours or 8.760 billion kWh. So a 5GW SSPS would essentially produce a little more than about 5 nuke plants. If that's correct would need just under 200 SSPS to power a hydrogen based transportation economy instead of 1,000 nuke plants.