Cleaning Up Our (Power) Act
The world needs carbon-free power, ASAP. Solar power, wind, wave, tidal, hydro, geothermal, — these are ways of generating power that don’t produce greenhouse gases. The problem is getting enough of it in the right place in the right amounts at the right time. Coal, oil, natural gas — they can be collected and transported to power plants located where there’s demand, and supply power when needed, as much as needed.
Wind, wave and solar are carbon free — but they’re intermittent and diffuse. Obtaining power from these requires large collection installations to ensure there’s always enough power being generated from some part of the system to meet demand — that and supplementing it with some other power sources for when the wind dies or the sun goes down. Additionally, finding ways of storing power at low demand times is one way to have power ready when demand picks up.
Geothermal doesn’t have the intermittency issue, but like hydropower, and tidal there’s only so many places where conditions are right to tap it. Hydropower is also problematic in other ways; heavy rains can force dams to release water at a time when flooding downstream is already a problem. Extended drought can mean there’s not enough water to generate power, as Venezuela is finding out.
Still, carbon-free means of power generation are gaining because the costs of solar and wind generation are coming down, and storage technologies are developing that make them more versatile.
And Then There’s Nuclear
All current nuclear power is based on the controlled breakdown of uranium atoms (or other heavy elements) which generates enough heat to boil water for steam turbine generators. This is called nuclear fission AKA atom splitting. It’s been around for decades, it’s carbon free, and it can be ramped up and down as demand fluctuates.
It also requires heavy shielding because of radiation, creates long-lived radioactive waste, is unforgiving of operator errors or accidents, and is also affected by climate. Siting and building nuclear power plants is complex, expensive, and takes years, although newer reactor designs are supposed to mitigate some of these issues. There’s also the risk of nuclear power programs becoming nuclear weapon programs and targets for terrorists. Uranium isn’t all that plentiful either, and mining it has a whole raft of problems associated with it. Which leads to…
Fusion — the OTHER Nuclear Power
Where fission releases energy by splitting atoms from heavy atoms like uranium, fusion works by fusing small atoms into bigger ones — and some of the mass of those atoms ends up getting released as energy in the process. The sun and the other stars we can see are giant fusion reactors; they’re big enough that their gravity is enough to squeeze smaller atoms together, while keeping them from being blown apart. The high temperatures found in stars also contributes to the process. The Sun is turning hydrogen into helium.
Humans have been able to do fusion as well — but not as a power source. The Hydrogen bomb uses an atomic fission bomb as a trigger; the heat and pressure generated by the atomic bomb is what — briefly — provides the energy to create a fusion explosion. Trying to do it in a way that can be harnessed to generate power is difficult. Heavy atoms like uranium spontaneously fission on their own — the trick is to keep them from doing it too fast. Light elements like hydrogen are extremely resistant to being squeezed together — it’s an uphill battle all the way.
Nonetheless, fusion power is attractive because suitable fuels are readily available, and there’s little danger of a runaway reactor because fusion is so hard to do in the first place… IF you are using heat and pressure to do it. It’s actually easy enough to do by alternative means that high school students and hobbyists have built working fusion reactors that can fit on a table top. Alas, Farnsworth type fusors consume more power than they create in the process. Still, they demonstrate there’s more than one way to fuse atoms together, and there’s increasing interest in developing some kind of practical fusion power plant.
An international consortium is working on the ITER fusion project. It’s based on a tokamak design, which has been around for a while. The project is way over the original budget, years behind schedule, has the expected international bureaucratic complications — and no one yet knows how well it will work. The key test for a fusion reactor is the so-called break even point. That’s when the power it produces matches the power it takes to operate it. Getting past break even — and at an effective cost — is the big obstacle. They hope ITER will make break even, and pave the way for working fusion reactors.
Others are looking at alternatives. The BBC has a report on some projects being funded by an eclectic mix of very wealthy people.
General Fusion is just one of a pack of private fusion firms to catch the attention of physicists and investors. Unencumbered by red tape, these venture-backed companies believe that they can find a faster, cheaper way to fusion than government-sponsored projects, and some very influential people agree: besides Bezos, Microsoft cofounder Paul Allen and PayPal cofounder Peter Thiel are also backing firms at the forefront of fusion development. Some of these enterprises have operated almost entirely under-the-radar until recently: the company Allen is invested in, Tri Alpha, didn’t even have a website before last year.
The combination of wealthy moguls and fusion is curiously reminiscent of the 2012 Batman movie ‘The Dark Knight Rises’, in which Bruce Wayne’s company builds a fusion reactor behind closed doors. The movie wouldn't win any awards for scientific accuracy, but it got at least one thing right: this world-changing technology may indeed be ushered into existence by a moonshot-minded magnate.
They’re pursuing several different approaches; one that’s been under development for a while by a different route is the Polywell reactor.
Funded as a U.S. Navy research program for some years on a shoestring budget, the team behind it has made a lot of progress. Alas, the contract ended in 2014. It's a rather annoying paradox; the technology they've developed is designated too sensitive to be shared with foreign investors, yet the government won't fund it.
(There’s also suggestions that the Department of Energy thinks THEY are the ones who should be doing fusion research, not the Navy, and they’re loaded with people who are heavily committed to a different fusion technology.)
Still, the EMC2 company thinks they're finally close to getting permission, and could build a working scaled down prototype in 3 years for only $30 million, a bargain by fusion research standards. They think the design is efficient enough that it could operate on a proton-boron fusion reaction, an ideal choice of fuel for a variety of reasons.
Still, why would anyone invest in fusion power when other carbon free technologies have made such progress? Part of it is flexibility. A working fusion reactor doesn’t depend on natural conditions to generate power. It can generate it as needed, when needed, and doesn’t require large amounts of space like a wind or solar panel farm. It’s easier to connect into the grid when you can leverage the existing network built around current generating plants. Assuming it’s not something as huge as ITER, you can build the fusion reactor next door, then throw the switch and turn off the old carbon emitters. The radiation, waste, and terror risks are minimal.
There’s an old joke that fusion is the power of the future — and always will be. Well, the future may finally be getting here, and not soon enough!