Thursday, February 18, 2010

Innovate to Zero - an energy imperative

The necessity for carbon-free energy
Bill Gates' incisive talk on energy was one of my favourites this year. His acute analysis went step by step through his thinking with startling clarity. (In fact, if you want a template for a perfectly formed presentation, you could do worse than use this model.)

The Gates Foundation is working on vaccines and seeds. But climate is more important to the very poor than anything else. And the price of energy is critical to them too. In order to arrest climate change,we need to do more than just reduce carbon - we have to Innovate to Zero, from the current 26B tons of carbon/year (of which the US is responsible for 20B tons).

Carbon math is inescapable

Carbon = Population x Services/person x Energy/service x Carbon/unit of energy

Gates dryly pointed out the simple mathematical fact - if you want carbon to go to zero, then one of the terms of this equation has to go to zero. We can take the terms one at a time. Population is going to rise to 9B before leveling off. Services per person are rising as huge numbers reach for the middle class. Efficiency can drive down Energy per service, but realistically, not to zero. That leaves Carbon/unit of energy as the only factor that can be driven to zero. That requires a miracle. And we need to achieve that miracle by 2050.

Next, Gates identified five candidates for that miracle:
  • carbon capture and storage
  • nuclear
  • wind
  • solar photovoltaic
  • solar thermal.
Each approach has unsolved problems and concerns, and would take major breakthroughs to deliver the miracle. We need thousands of people working on all these challenges and he exhorted that work to begin.

The potential of nuclear
Gates pointed to nuclear as a strong contender in this race. The current technology in nuclear power plants dates back to the 1950s and uses rare enriched uranium. Furthermore, the process is quite inefficient and produces a lot of waste, without a sound plan for its disposal.

Gates disclosed that he is backing an initiative out of Intellectual Ventures, run by his friend and former CTO of Microsoft, Nathan Myrvold. Terrapower's uses U25 (i.e. spent uranium that is now considered nuclear waster) as fuel, rather than U28. It has the potential to use all that nuclear waste we now worry about so much. Even better, the process takes place in a sealed reactor in the ground, which you fill once every 60 years, eliminating the risks of accidents associated with refuelling. This approach has the potential to meet the deadline, through 20 years in development and 20 years for wide deployment. (Gosh, as much as I admired Gates' analysis, I wouldn't go so far as to put him in charge of a deadline!!)

The Gates talk is one of the first to go up on here. It's well worth watching.

Other TED talks on nuclear

Nuclear wove its way through a couple of other TED talks. Stewart Brand, an early environmentalist and creator of the Whole Earth Catalog has come to the conclusion that nuclear is the only answer. The risks of nuclear are less than the risks of climate change. And TerraPower's approach reduces those risks further. He outlines his reasoning in his new book Whole Earth Discipline: An Ecopragmatist Manifesto. He participated in a debate about nuclear power against Mark Jacobson, a Stanford civil and environmental engineer, whose most persuasive argument against nuclear power was that it couldn't come online fast enough to make a difference, mostly because of regulatory delays. That's the 20 years Gates allows for deployment after development has proven the concept.

And of course one couldn't help but link the Countdown to Zero movie (described in an earlier post) with Innovation to Zero. Using nuclear power creates a market for the uranium in all those weapons that should be dismantled).


Rod Adams said...

Lib - You made a small error - U-235 is the rare isotope of uranium at 0.71% of naturally occurring uranium. It is the material that most often fissions in current generation reactors.

U-238 is the far more abundant isotope at 99.29% of naturally occurring uranium. It makes up the vast majority of the material that is left over after use in a current generation reactor and is considered by some to be a waste product. (There is more than a million tons of U-238 in storage as a material called "depleted uranium" meaning that the U-235 was taken out in an enrichment plant.)

U-238 can fission - it just takes two neutrons instead of one to make that happen. The first neutron converts U-238 into Pu-239 (via a couple of nuclear reactions) and then the second neutron fissions Pu-239.

Gates's TerraPower has a reactor concept that makes good use of the ability of U-238 to fission slowly. It is sort of like the fission equivalent of a good fire that uses kindling to get started and then slowly burns up sizable, but difficult to ignite, logs.

Rod Adams
Publisher, Atomic Insights
Host and producer, The Atomic Show Podcast

Lib Gibson said...

Thanks for the clarification. I was taking notes as fast as I could, but obviously missed a key fact.

Lib Gibson said...

Thanks for the clarification. I was taking notes as quickly as I could, but obviously missed something.