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The question isn't, "what's the cheapest fuel at the moment?" The question is what's the cheapest carbon-neutral power source that could scale up to meet future

The question isn't, "what's the cheapest fuel at the moment?" The question is what's the cheapest carbon-neutral power source that could scale up to meet future global demand? Daniel Nocera has been arguing for years that using solar energy to split water into hydrogen (ie. the "artifical leaf") is the best strategy. Not even nuclear can scale to meet global demand[1]. But solar devices can be mass manufactured and distributed to the point-of-use (leap-frogging the need for massive infrastructure investment).[2] 1. http://web.mit.edu/professional/pdf/DGN_Daedalus.pdf http://web.mit.edu/professional/pdf/DGN_Daedalus.pdf > "Delivering this TW-value with nuclear energy would take the construction of eight thousand new nuclear-power plants. In other words, over the next forty-five years, we would have to construct one new nuclear-power plant every two days." 2. https://www.youtube.com/watch?v=12VPW-wS8yc https://www.youtube.com/watch?v=12VPW-wS8yc

darkmighty 12y ago
If a 'artificial leaf -> fuel cell -> power' is less efficient than 'photovoltaic cell -> battery -> power' and the cost is comparable, I don't see how your point is valid. Yes, we'll need a lot of energy, but note that that figure is for the whole world. I think it's doable. Hell, it's the best alternative so 'doability' doesn't really matter, but I guess we'll see how close we'll get (with nuclear+solar). Note that china alone has 200 nuclear plants in project right now [1]. [1] http://nextbigfuture.com/2015/02/china-could-build-200-nuclear-reactors.html http://nextbigfuture.com/2015/02/china-could-build-200-nucle...
- baddox 12y ago
  It depends how you're calculating efficiency. If you're talking about solar input to usable output, I contend that efficiency doesn't actually matter that much (at least until we start using a sizable portion of Earth's solar input). What matters more is dollars per watt. Last I checked (several years ago), simple solar heat engines were considerably cheaper per watt than photovoltaics (for generating electricity), even though photovoltaics were considerably more efficient by the former metric.

darkmighty 12y ago

If a 'artificial leaf -> fuel cell -> power' is less efficient than 'photovoltaic cell -> battery -> power' and the cost is comparable, I don't see how your point is valid. Yes, we'll need a lot of energy, but note that that figure is for the whole world. I think it's doable. Hell, it's the best alternative so 'doability' doesn't really matter, but I guess we'll see how close we'll get (with nuclear+solar). Note that china alone has 200 nuclear plants in project right now [1]. [1] http://nextbigfuture.com/2015/02/china-could-build-200-nuclear-reactors.html http://nextbigfuture.com/2015/02/china-could-build-200-nucle...

baddox 12y ago
It depends how you're calculating efficiency. If you're talking about solar input to usable output, I contend that efficiency doesn't actually matter that much (at least until we start using a sizable portion of Earth's solar input). What matters more is dollars per watt. Last I checked (several years ago), simple solar heat engines were considerably cheaper per watt than photovoltaics (for generating electricity), even though photovoltaics were considerably more efficient by the former metric.