Wednesday, May 23, 2012

A rosy look at energy future

kw: energy, speeches

I have been out of pocket a few days, at a company conference. I was particularly interested in today's keynote speech, given by Dr. Stephen Chu, the Nobel laureate physicist who is the Secretary of Energy. The opening section of his address was the most compelling case I have so far seen supporting the theory that humans are at least partly responsible for the current climatic warming, AKA "global warming". While he acknowledged that scientists are still uncertain about all the parameters, that uncertainty is a scattering of opinion around a very bad prognosis. For example, the carbon dioxide proportion of the atmosphere has varied quite a lot over the past million years, but has not exceeded 350 ppm. The present level is 420 ppm, and the debate is whether, by the year 2100, it will be closer to 550 ppm or 900 ppm. There is no realistic scenario of future energy use that predicts a level below 500 ppm.

Much more of his talk was devoted to some hopeful trends. The best batteries now used in hybrid and electric autos have a performance factor of about 200, which I think is in w-h/kg. 200 something, anyway. Prototypes in the lab right now are performing in the 400 range, and technologies being studied promise to push energy densities into the 600-800 range. That means a battery pack for the Chevy Volt, which can drive the car about 60-80 miles between charges, might one day be replaced with one that can take it 250-300 miles, yet be recharged in less than an hour. That's great, as long as you don't have to replace a $5,000 pack every year or so. They need to last ten years, like the rest of the car.

He also showed a number of "experience charts", showing how the price of an item drops as manufacturers get more and more experience making it. For certain appliances, such as refrigerators, not only has the cost of making them gone down, but the imposition of standards for energy use have made their lifetime cost go down even more, yet the purchase price has continued to fall. Compared to 1975, a refrigerator is twice as large, costs less (in constant dollars), and uses one-third the energy. Other appliances have followed a similar path.

In answer to a question, he said that the level of energy per capita translates into GDP in an almost linear fashion, up to a point, then levels off. That means that many of the world's poorest couple of billion people can be brought to a much more prosperous level with an increase in energy use that is quite modest, compared with the "western standard".

I am inclined to take another look at the speech, which was recorded, and take notes. I want to check some of the rosy predictions he makes. If enough of them bear up, I will have a greater level of comfort that the world we are leaving to our children and grandchildren may not be the dystopian nightmare so many of my contemporaries predict.

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