Green Energy, Tidal, Solar, Nuclear

Lynne Kiesling

There’s an interesting Slashdot thread today about EPRI’s offshore wave power demonstration project. What’s interesting to me about the thread is not just the feasibility report, but the information about various other “green energy” technologies that is contained in the comments. This commenter points out that all of those appliances that we take for granted are the source of residential energy demand, not computers. Another commenter says that burning coal creates more radioactivity than nuclear energy (in addition to the traditional pollutants), a point argued in this article from Oak Ridge National Laboratory. The ORNL article references a 1978 paper that finds

Former ORNL researchers J. P. McBride, R. E. Moore, J. P. Witherspoon, and R. E. Blanco made this point in their article “Radiological Impact of Airborne Effluents of Coal and Nuclear Plants” in the December 8, 1978, issue of Science magazine. They concluded that Americans living near coal-fired power plants are exposed to higher radiation doses than those living near nuclear power plants that meet government regulations. This ironic situation remains true today and is addressed in this article.

The fact that coal-fired power plants throughout the world are the major sources of radioactive materials released to the environment has several implications. It suggests that coal combustion is more hazardous to health than nuclear power and that it adds to the background radiation burden even more than does nuclear power. It also suggests that if radiation emissions from coal plants were regulated, their capital and operating costs would increase, making coal-fired power less economically competitive.

Interesting; I did not realize this!

The thread also has a lot of generally sensible and insightful comments about nuclear energy, the replacement of fully depreciated old reactors with new pebble-bed or pressurized water reactors, etc.

I was also struck by this commenter’s calculations of the land area that would have to be covered by solar panels to power world energy demand. His “back of the envelope” calculation suggests that rather than paving 1/3 of the world’s land with solar panels, it would require only 2%. This comment is a nice example of how well the Internet facilitates this kind of conversation, and how easy is makes for him to support his argument with authoritative links. I would challenge one crucial assumption he makes, though, which is that solar panels are 20% efficient. That is an overestimate, and it biases his result downward. This Wall Street Journal article from November 2004 about Konarka, a company that uses nanotechnology to make solar energy strips, suggests that 17% is currently only achievable with the mainstream technology under optimum conditions. That claim is consistent with other sources I’ve read and talked to.

One thing in the way this commenter phrased the end of his comment made my ears perk up:

There needs to be a 10X reduction in the price/energy ratio of photovoltaics. Do that, i.e. reduce the cost of the solar energy to meet the world’s needs to an investment of about $100 trillion, amortize it over 30 years, and I’m sure we can find the money and land to do this.

I do not know what the commenter’s intent was in that sentence, but in me it triggered a visceral reaction of “what, you think we can reduce the cost of solar energy auto-magically?” I find that sometimes when discussing economics with energy scientists and engineers I encounter a mindset of “well, just make it cheaper and people will adopt it and all will be hunky dory and in accordance with my theory/model/simulation”. My question is, what is the process by which we make things cheaper? How quickly can that happen? What are the costs and benefits of artificially accelerating that process? We can’t just snap our fingers or pass a new law and make solar energy “cheaper” in any kind of truthful, meaningful, realistic, long-term sense. Sure, I’d love to, just like I’d love to snap my fingers and have every house, store, and office outfitted with a smart 2-way communications-enabled electric power meter.

Wishin’ don’t make it so. Thought, creativity, initiative, drive, persuasion, investement, research, and striving do. But those take time and resources.