SEP 22, 2016 @ 12:32 PM
We Could Power The Entire World By Harnessing Solar Energy From 1% Of The Sahara
Could the world feasibly switch to all-nuclear power generation? If so, would that be a good counter to global warming?originally appeared on Quora: the knowledge sharing network where compelling questions are answered by people with unique insights.
Answer by Mehran Moalem, PhD, UC Berkeley, Professor, Expert on Nuclear Materials and Nuclear Fuel Cycle, on Quora:
I have taught courses in Nuclear Engineering and a few seminar courses in alternative energies. I also worked for two years starting up six solar factories around the globe. In spite of my personal like for nuclear engineering, I have to admit it is hard to argue for it. Here is the simplified math behind it.
The total world energy usage (coal+oil+hydroelectric+nuclear+renewable) in 2015 was 13,000 Million Ton Oil Equivalent (13,000 MTOE) – see World Energy Consumption & Stats. This translates to 17.3 Terawatts continuous power during the year.
Now, if we cover an area of the Earth 335 kilometers by 335 kilometers with solar panels, even with moderate efficiencies achievable easily today, it will provide more than 17,4 TW power. This area is 43,000 square miles. The Great Saharan Desert in Africa is 3.6 million square miles and is prime for solar power (more than twelve hours per day). That means 1.2% of the Sahara desert is sufficient to cover all of the energy needs of the world in solar energy. There is no way coal, oil, wind, geothermal or nuclear can compete with this. The cost of the project will be about five trillion dollars, one time cost at today’s prices without any economy of scale savings. That is less than the bail out cost of banks by Obama in the last recession. Easier to imagine the cost is 1/4 of US national debt, and equal to 10% of world one year GDP. So this cost is rather small compared to other spending in the world. There is no future in other energy forms. In twenty to thirty years solar will replace everything. There will still be need for liquid fuels but likely it will be hydrogen produced by the electrolysis of water and that powered by solar. Then tankers and pipelines will haul that hydrogen around the world. One can also envision zirconium or titanium batteries that store large quantities of hydrogen.
By the way, note that the cost of a 1 GWe (Gigawatt electric) nuclear plant is about three billion dollars. the cost of 17.3 TW nuclear power will be fifty-two trillion dollars or ten times that of solar even if all the other issues with safety and uranium supply are resolved.
All that said, there is a niche application for nuclear power....
Not a deep analysis, but an interesting recitation of a widely held conceptualization of how the transition might proceed. The problems aren't insurmountable, but I'd expect such a centralized model would have (too) high distribution costs and be too subject to disruption as an outcome of normal cussed human in-fighting.
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