Weird Science posted a response in our back in forth on future energy. Bruce at Weird Science has some fundamental inconsistencies in how he views the future which are problematic.
Contradictions and Inconsistencies and Unjustified Criteria
Weird Science talks about accepting fossil fuels for 70 years and wanting a future energy source to last for 700 years. These are just numbers that are pulled out of the air or are guesses based on simplified assumptions. Plus the timeframes are so long and sweeping that any analysis requires a laundry list of assumptions and predictions about that the many different 70-700 year scenarios are. I occasionally write about the far future but the farther out you go then the upside scenario becomes trying to get the right century or millenia when humanity might move into a new kardashev classification. The variance can become billions of times different depending upon how things play out. The downside scenario becomes we are all dead.
Fossil fuels could last 200 years or an aggressive program and good technology could cause a major shift from fossil fuels within 50 years.
Displacing coal and a lot of Oil over 50 years
Deeper burn could allow uranium to be used 50 times more efficiently (use all uranium isotopes and use most of the 65% of heat that is not utilized). Instead of using 68,000 tons of uranium to provide 17% of world electricity or 7% of total power needs (including transportation and industrial uses.) you could use the same annual amount of mined uranium to provide triple the worlds electricity and double the industrial heat. This would mean getting up to around 60% conversion of heat to electricity and utilizing the rest of the heat for industrial. Electrification of transportation would allow a lot of the oil to not be used.
Factory built deep burn nuclear fission could be a part of displacing coal. Hyperion Power Generation making thousands of uranium nitride and then uranium hydride reactors could have a major impact from 2013-2030+. China pebble bed reactors starting with HTR-PM will be continuously improving major system. Liquid flouride thorium and accelerator based nuclear reactors could be developed 2025-2035.
Basically consistency for a 70 year forward scenario would say that the future energy source has 20-50 years or so to perfect itself and then 20-30 years to be deployed and be ready for the handoff. China is planning to have nuclear breeders fully ready and deployed in 2050. My scenario about ffactory built deep burn reactors has several active projects actually succeeeding. However, the Weird Science analysis assumes that nuclear fission technology and their economics stays static for 70-700 years.
I do not concede Another 70 years to Fossil Fuels
70 years of using coal and oil the way we do now would mean over 200 million premature deaths from air pollution.
I do not concede that Uranium from Seawater will Remain Uneconomical
Here is some cost analysis of uranium from seawater
Uranium from seawater could provide poewr now if we were willing to pay 50% more per kwh for electricity
There are several ways to scale up the lab work to commercial scale for uranium from seawater
Weird Science quoted one proposal that said “only” 6 tons of uranium per year could come from a continuous uranium from seawater process, but that was only one proposed setup. This is like you can saying you can only get 6 tons of fish from one fishing line from one boat. You can have tens of thousands and even millions of boats and lines or alter a process to have big boats and drift nets. How many assembly lines are there for cars and computers ? Not just one. 1 million uranium lines would mean 6 million tons per year. It is the whole civilization we are talking about. So I do not support the claim that seawater process is uneconomical or unable to produce the volumes needed. The processes will of course be improved to reduce the costs. Plus even at $200/kg the fuel costs of a nuclear reactor are small. Especially a breeder reactor that has deep burn. Full burn uses 50 times less fuel to generate the same power. Fuel costs can then go up 50 times and still be the same fraction of electricity cost.
There has bee no analysis of what Japan is planning to do. The large scale growth of bioengineer seaweed for both biofuel and uranium from seawater extraction. This is one of the proposals that is the closest to moving forward.
The effect of Removing Uranium from Seawater
River runoff adds 6,500 tons per year of uranium into the oceans. Integral fast breeder reactors or other deep burn reactors could provide double the current world electricity usage from that uranium. There is about 3.5 billion tons of uranium in seawater. Humanity could remove 1.7 billion tons to get the concentration down to half. Plus the number of years this took would add back in 6500 tons of uranium each year from runoff. 1.7 billion tons of uranium would last far longer than 700 years in almost any scenario.
Thorium Starts boosting Fission fuel Supplies starting in 2020
There is also the thorium in the earths crust. Three times as much as the uranium. How thorium becomes uranium in a reactor is explained here.
India is working to use thorium in reactors. A couple of startups are working to produce thorium fuel rods for existing reactors. They target 2020-2025. They are funded and doing experiments in actual reactors.
Accelerator driven reactors also have complete burn. It is getting cheaper and cheaper to make neutrons. With neutrons you can convert uranium 238 to plutonium 239 and again achieve complete burn.
Uranium from Phosphate has been done for decades. A few thousand tons of uranium per year. There is over 6 million tons of uranium in phosphate in known reserves.
Far Future Speculation
What is my speculation on what will happen to humanity and its energy needs for 70-700 years in the future ?
This is becomes totally disconnected from current technology.
We will probably have :
dyson shells swarms, molecular nanotechnology, Extreme AGI, control of casimr forces, mach effect
control of casimir forces is already starting
including repulsive sasimr forces
Accessing the mach effect for power generation or propulsion would also be a fundamental pivot for future possibilities.
I forecast a technological singularity by 2060 at the latest and radical changes before then. So discussing energy in the 70-700 year timeframe is like a debate about modern energy by cavemen.
Energy because it can take currently take 40 years to make a major shift in the energy generation mix lets you try to plan out for 100 years but you have to expect to be wrong. You just have to be less wrong then someone elses assumptions and plans and provide a better path forward. Even energy planning beyond 100 years is just nuts. Even population projections beyond 50 years are whack. The rate of making babies shifted a lot from 1960 to today.
I believe we will have full blown diamondoid nanofactory molecular manufacturing in 30 years max.
Bruce have not acknowledged my points about breeders etc… You said no tech and I pointed out that breeders exist and operate fine and there will about dozen or a lot more (with hyperion power generation and the Russian 100 Mw version) very soon.