A Serious Solution to Carbon Emissions
As I’ve made clear before, I remain skeptical that carbon emissions pose a significant marginal threat of climate change. The likely climate sensitivity to CO2 is substantially less than the natural variability over human timescales. Seeing as how temperature trends over geologic time scales are currently downward, I don’t think it’s worth wasting much effort on CO2 reductions.
However, let’s assume for a moment that I’m wrong. What should we do? I don’t think we can actually decrease our energy usage very much and support our civilization. So we have to find non-petroleum energy sources. Biofuel technology doesn’t look very good at the moment. Scaling will require major land use changes that I contend are probably a net negative environmental impact. The cost-benefit for solar does look better, especially in certain geographic areas. But it seems to me the only massively scalable solution at our current level of technology is nuclear fission.
From an engineering perspective, this looks like a pretty obvious conclusion. The problem is that standard light water reactor (LWR) technologies have some serious drawbacks: (1) they don’t scale down well so you need to build big installations, (2) you can’t easily turn them on and off quickly so they typically only supply your base load, and (3) they generate a substantial amount of radioactive waste that we still haven’t figured out what to do with long term. So even if we can overcome the ideological resistance to nuclear power, there are also some serious fundamental economic issues to overcome as well.
Enter the thorium fuel cycle, from which you can build a Liquid Fluoride Thorium Reactor. It essentially solves all these problems and they are simpler to manufacture because you don’t need giant pressure vessels. They can scale down to 5MW. If you’re willing to run them at only slightly lower efficiency, you can use them for load following and peak reserve roles. They generate about .1% of the long term radioactive waste as standard LWRs. It’s also incredibly difficult to reprocess fuel into weapons-grade material.
The coolest part is you can mass produce the components and then assemble them on site so we could actually get these babies up and running quickly. For details, see the Energy from Thorium blog and site (I recommend starting with the former and moving on to the latter’s discussion forums and document repository if you want gory details).
Run your Tesla on clean, reliable thorium power!