Distant Future CleanTech: Where Will The Energy Come From?

Right now, humanity is worried about energy. Not only do we need more of it to meet growing needs, but we also need to address climate change. So we are in the process of a monumental effort, an effort that’s basically the whole point of CleanTechnica. But just because we’re in the midst of such a huge challenge doesn’t mean we can’t look forward to cool things in the future, and even future challenges our descendants will face.

The Kardashev Scale & Its Problems

People have been looking at the distant future of energy use for a long time. Soviet astrophysicist Nikolai Kardashev even came up with a way to categorize advanced civilizations based on their energy consumption (The Kardashev Scale):

  • A Type I civilization can use as much energy as is available on its whole home planet, and store it for productive use.
  • A Type II civilization can use as much energy as produced by its star.
  • A Type III civilization can use the energy of a whole galaxy’s worth of stars.

Where does humanity lie on the scale? We’re definitely not anywhere near even Type I. Some people have estimated that we’re a Type 0.6 or 0.7, but keep in mind that the scale isn’t linear. Type 0.6 isn’t six tenths of the way to Type I, because each step up (I, II, III) is millions of times greater than the step before it. So, we’ve still got a looooong way to go before Type I.

But there are two problems with the scale.

First, it’s rooted in mid-20th century assumptions about energy use. Both the United States and the Soviet Union used the same basic industrial technologies, with the latter purchasing much of the former’s equipment prior to World War II. During the Cold War, the First World War, the Second World War, every developed Third World country (this really makes sense if you know what Third World really meant — it’s not a synonym for “poor” or “developing country”) only advanced by using more and more fossil fuels or nuclear power.

But now, we’re seeing that using more energy doesn’t necessarily mean a technology or the people using it are objectively better. In fact, being able to do more with less energy is the better approach for sustainable development. So, it’s entirely possible that the descendants of humanity (who may or may not really be very human) or alien civilizations don’t climb an insane ladder of energy use as Kardashev thought.

A related question is whether a civilization is doing something useful with its energy. One blogger estimates that the human civilization depicted in Pokemon uses a lot more energy than the human civilization depicted in Star Trek, giving it a higher Kardashev number. While I think capturing and training magical animals is a cool concept, doing that is probably a lot less useful than interstellar travel, saving millions of lives, and otherwise spreading truth, justice, and the Starfleet way. But that’s just me.

It’s entirely possible that an advanced civilization with a religious fetish for wasting energy (kind of like Republicans and Hummer EV drivers, but on much larger scales) could achieve an impressive Kardashev number while doing nothing useful or good.

The second problem with the Kardashev Scale is that achieving certain milestones may be too destructive. Let’s do what we always do, and use humanity for our example (it’s the only sample in our set, unfortunately). If we were to generate the energy that falls on our planet by burning fossil fuels, we’d both run out of them and quickly destroy the planet’s systems, causing our extinction. If we were to capture all of the energy that falls on the earth with solar panels, we’d lower the earth’s albedo to the point where we absorb too much energy, produce too much waste heat, and roast ourselves out even worse than with fossil fuels. Even then, we wouldn’t achieve Kardashev Type I. Damn.

Here’s a good video that explains the problems in more fun ways than I can here:

Becoming An Insanely Advanced Civilization Means Leaving The Planet

As the video points out, we’re not going to be able to even get to Type 1 as a species if we’re all on Earth. We’d destroy ourselves with the waste heat alone, and that’s before we consider climate change. Even now, our waste heat (the heat that comes off of vehicles, air conditioners, and everything else) that’s produced just by the buildings in cities measurably affects the climate hundreds and even thousands of miles away from major cities.

The effect of waste heat is small compared to climate change, but it would still become a problem if we were to urbanize too much of our planet, even if those mega-megacities were powered completely by renewables. So, no matter what, we’d better have space colonization in our future if we want to keep multiplying and growing our population.

But, that still leaves questions of how to get energy off-world. Space probes that we’ve sent far from the planet (by present-day standards) have historically been powered by some kind of nuclear reaction. More recently, we’ve been incorporating solar panels on space probes, Including using them to power a small helicopter on Mars. So, having at least some energy isn’t going to be a problem.

Other possibilities include Dyson Spheres, or containers for stars that collect all of their energy, and exotic things like matter-antimatter reactions. These each have their own challenges and problems, and in the case of antimatter energy, it’s tough to make and store the stuff.

But, if we decide it’s necessary to generate even more insane amounts of energy away from Earth, we’re going to need to start thinking bigger than solar panels, wind turbines, and other sources of energy that ultimately come from stars or the formations of solar system.

One Idea To Get Insane Energy: Steal It From Black Holes

A couple of videos from the Cool Worlds YouTube Channel give us a possible way to get as far as Kardashev Type III, which is really unimaginable in many ways. But, just because something is unimaginable doesn’t mean we can’t run the numbers on it.

The videos’ creator first tried to come up with a method of interstellar travel. If you came close enough to a black hole and fired a laser in just the right spot to the side of it, the black hole’s gravity would cause the light particles to “slingshot” around it and come back to you, like a boomerang. The light is already going the speed of light, and can’t go any faster, so the extra energy the light picks up would change its wavelength. This means that you’d get more power back than you sent out.

This wouldn’t be a perpetual motion machine, as the energy does come from the black hole. If you drew enough power from it in this way, you could theoretically use the same energy as a Kardashev III civilization for 1,000 years before the energy runs out and the laser stopped coming back with greater energy. If you were to draw a lot less energy, you could run a Kardashev I or II civilization for millions of years this way.

You could also create an “interstellar highway system” with possible speeds of 20% the speed of light using technologies possible today. If future humans/transhumans came up with something like a warp drive, they could use this energy to go much faster. Problems would have to be solved, especially the fact that the laser beam would push you away at great speeds.

But, if we could solve it, there’s not much reason humanity couldn’t achieve insane levels of development in the future–if we survive to get that far. But, as many black holes as there are, there is still a finite number of them, and a future civilization could potentially mine them all out of energy. So, sustainability is a challenge our descendants will deal with far into the future.

Feature image by Indif, CC-BY-SA 3.0 License.




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