Monday, October 15, 2007

The Solar Power Satellite Gets a Good Second Look

Here's the executive summary of the National Space Society report on space-based solar power (SBSP.)

I've been in favor for a long time: SBSP would be environmentally friendly (or at any rate, friendlier than burning fossil fuels), and it would provide such a vast amount of power that raising the entire world to western standards of living would be enormously easier.

But sadly, it's a sign of the times that the penultimate paragraph also plays to the usefulness it would have for empire-building:

For the DoD specifically, beamed energy from space in quantities greater than 5 MWe has the potential to be a disruptive game changer on the battlefield. SBSP and its enabling wireless power transmission technology could facilitate extremely flexible “energy on demand” for combat units and installations across an entire theater, while significantly reducing dependence on vulnerable over-land fuel deliveries. SBSP could also enable entirely new force structures and capabilities such as ultra long-endurance airborne or terrestrial surveillance or combat systems to include the individual soldier himself. More routinely, SBSP could provide the ability to deliver rapid and sustainable humanitarian energy to a disaster area or to a local population undergoing nation-building activities. SBSP could also facilitate base “islanding” such that each installation has the ability to operate independent of vulnerable ground-based energy delivery infrastructures. In addition to helping American and allied defense establishments remain relevant over the entire 21st Century through more secure supply lines, perhaps the greatest military benefit of SBSP is to lessen the chances of conflict due to energy scarcity by providing access to a strategically secure energy supply.

One thing the report doesn't mention - and something I hadn't given much thought to until recently - was that beamed power offers a great method of control, one that is in fact very similar to the water economies of ancient kingdoms. Basically, in a heavily irrigated agricultural system, where there is little rainfall and most water comes from a single source, he who controls that source is the absolute ruler of all. If there's a rebellion in province A, but provinces B and C are loyal, guess who gets cut off when there's a 'drought'? Regions with such a geographic curse inevitably turned into mass dictatorships, with small elites lording it over hordes of ant-like subjects who were little better than slaves. In contrast, areas with rainfall, where farmers could make their living more or less where they pleased and not have to worry about water, slave-states had a harder time getting a foothold. Political evolution was slower, but when it came it was forced to accommodate more local and personal autonomy, and in the end that led to more effective societies.

For all of the other flows on which our lives depend - those of money, information, food, and water - the flow of energy is the most crucial. Cut it off, and every other flow is interrupted; before long life becomes impossible. It's our civilization's equivalent to the water of the ancient world.
Now, if the main source of energy for most of the planet is a giant swarm of SBSP satellites beaming power down to the world, whoever controls that power controls the world. Like the kings of old, people or cities or countries could be shut off at will. On top of that, there's the weapons systems this will make possible (orbiting fortresses that can project force anywhere on the Earth in a matter of seconds, and of course, never need to come down). It's easy to see how an empire would rapidly build itself around control of an SBSP.

An empire isn't a foregone conclusion. For one, actually building an SBSP is likely to be a multidecade project (with a large part of the progress being towards the end, perhaps in the midst of a stock-market bomb and the consequent spike in infrastructure construction.) The number of participating organizations, at least initially, is likely to consist of a large number of small private companies. So long as ownership of the swarm does not at some point devolve into the hands of a monopoly, the possibility of an empire is much reduced. Unfortunately, current economic practices tend to produce monopolies - or cooperating oligopolies - across a wide range of corporate endeavor, with market share and capitalization tending to concentrate as an industry matures.

Another factor is that, just because there's a massive SBSP swarm beaming down cheap power, it doesn't mean other sources of power generation disappear. Much of the infrastructure might: all the old coal-fired and nuclear plants would likely be phased out. But nothing would prevent people from setting up their own, ground-based renewable energy systems (rolling out a tarp of solar collectors, deploying a wind turbine kite), or storing energy up against the possibility of the beamed power being interrupted. Still, the limits on the growth of beamed power are pretty forgiving (see: Dyson Sphere) so relying on whatever one can gather on Earth's surface will, over the long run, be an emergency measure upon which economies cannot

Of course, geosynchronous orbit or a Lagrange point - and the Earth's surface - aren't the only place to collect solar power. You can start building collectors on the moon, for instance. Or, if you were really ambitious, Mercury, where there's a nice big, low-gravity source of great building material, and a solar energy flux of 9.13 kW/m^2, which compares nicely to Earth's 1.37 kW/m^2 (and that's in orbit, not the piddling .68 on surface, during the day, when it isn't raining.) If we ever get into space, I guarantee a war will be fought over Mercury ... though that will be a war fought by machines, the beings that will ultimately colonize the world. It's utterly unfit for human habitation (I'm not so pessimistic about the rest of the solar system. My main beef with Mercury is it's complete lack of the volatiles needed to sustain complex organic chemistry.) At any rate, a rush to colonize Mercury - and the rest of the solar system - would be an effective counteragent against empire ... assuming, of course, it were allowed to happen. Earth would become a single state, but it would be just one of many.

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