SSP estimate for UK power grid

I think you need to factor in economies of scale on the solar panels.
Also you seem to be assuming that you have to buy all the satellites
and then launch them, in reality you probably set up a production line
and start launching, and get money back very early on in the project
which will help finance the later satellites. That way you only have
to borrow a few billion, maybe $5-10 billion.

On 15/03/2008, ANTIcarrot wrote:
> Well, a back of the envelope estimate at least. It's a lot of money, but a
> lot of savings too; and the basis for my 500-Prize proposition. Probably
> significantly in error, but the economics seem to make sense at twice the
> price. Any feedback welcome,
>
> John
>
> SSP 'back of the envelope' study for the UK grid.
>
> 10GW satellite weighs 100,000 metric tons with 1980s tech; same as a Nimitz
> aircraft carrier.
> Assume a transmitter twice as big, which produces a rectenna half the size.
> Assume $10B for material and assembly costs; as for a Nimitz.
> Launch costs for 100kT @ $500/kg = $50B
> Assume Rectenna costs $10B.
> Total per satellite: $70B
>
> The UK uses 372.6 billion kWh
> Hence average consumption is 42.5GW.
> Meter price of electricity is 0.1 or $0.2 per kWh
> Assume 50% of this translates directly as cost of coal/oil/gas.
> Hence fuel bill for power stations: $37.26B
>
> Five 10GW (or 10 5GW) satellites would cost $350 billion
> 2x Orbital construction yards (LEO & GSO): $10B (each)
> Cash prize to bring launch costs down to $500/kg: $10B
> Purchase launch fleet: $10B
> Equatorial land lease for launch facility: $10B
> Total costs: 200 billion = 11 years fuel costs = 33% of the British annual
> Budget. (618B)
> Cost to grid: 0.013/kWh - 0.026/kWh
> Space capacity: 7.5GW (Air conditioning for the underground, free electrical
> heating for the elderly, export, etc)
>
> The LEO construction yard would pass over an equatorial launch site 16 times
> per day
> If half these are used for launch, and the other half for recover, that's 8
> slots per day.
> DH-1 = 20MT per day & 7,305 MT per year - 60 years to completion. (not
> practical)
> DC-Y = 80MYT per day & 29,220 MT per year - 15 years to completion. (5 day
> turn around)
>

--
-Ian Woollard

We live in an imperfectly imperfect world. If we lived in a perfectly
imperfect world things would be a lot better.