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EADS? Egads! January 21, 2010

Posted by Maury Markowitz in solar power satellites.
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Who’s the latest company to float the space power trial ballon? That would be EADS Astrium, with another hand-waving article about IR lasers and space power. Sigh.

Here’ lets do the math people…

The panels I use are 220 W each, and weight 20 kg. So each 1 kW of installed system needs 90 kg of panels.

Here in Toronto you’ll get about 1250 kWh of power for every 1 kW of panels you install. So divide that through to get 13.88 kWh per kg per year. Those panels will last about 25 years, on average, so over their lifetime you’re looking at 350 kWh of electricity, per kg.

So far so good?

Now take that panel into space. In space there’s no night, no clouds, and good pointing angles. This means you’ll get about 8,750 kWh per kW of panels you install. However, those panels are subject to a constant rain of particles, and generally only last 12 years. So that means every 1 kW of panel gets you 105,000 kWh of power. Sadly, as much as half of that is lost in transmission, but I’m going to completely ignore that for now.

So, that same 90 kg of panels is now going to generate 105,000 kWh of power, which is a hair under 1200 kWh per kg over their lifetime.

At this very second, baseload power is selling in Ontario for 3.3 cents a kWh. At 350 kWh per kg, in Toronto you’ll get $11.55 per kg. The same panels in space at 1200 kWh will produce $39.60. So that means the economic benefit of placing them in space is $28 per kg.

Current launch rates to GEO are $12,000 a kg. So in order for space-based power to get to the break even point, let alone being worthwhile, launch costs have to fall by three orders of magnitude.

The math is inescapable. Futz with your favourite technology and run the numbers yourself. Remember that anything that improves the price/performance or weight/performance of the panels also improves the economics of the same system on Earth, the only place you can get these three orders is from the launchers.

Talk about the space cannons and electro-pults all you want, none of those actually exist, and even their proponents only suggest two orders of magnitude improvements.

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Comments»

1. Ivan - January 22, 2010

I agree with your points – somehow all those semi-tech articles always focus only on the transmission aspect, as I guess the concept of blasting a microwave at Earth is the lowest hanging fruit in there (is it going to fry the geese that fly through it, har-har?)

But one thing I don’t understand is why everyone keeps on jumping on that same bandwagon. Clearly, for the researchers, it’s about governments throwing money at you to play with lasers and satellites. It doesn’t get much cooler than that. There seem to be, however, many large companies also involved, and they seem to be spending some of their own money. On a project that doesn’t break even before a multiple orders of magnitude miracle. Is there some sort of a patent race going on?

Maury Markowitz - January 23, 2010

I think the important thing to note is who keeps jumping on the bandwagon. In every single case, it’s a company that builds rockets, or someone who formerly worked in the aerospace industry. This is all just an excuse to build more rockets.


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