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(originally published by Booz & Company)


Energy Policy by the Numbers

A Cambridge scientist says it will take better arithmetic and less passion to replace fossil fuels by 2050.

There is more than enough analysis and positing these days about energy costs and policies, the impact of global warming, cap and trade, sustainability, alternative sources, and the like. But most of this posturing, says Cambridge physicist David MacKay, is merely “hot air.” 

Fed up with the cacophony, MacKay assembled a rational, non-political, “pro-arithmetic” analysis of what can be done to wean energy users (businesses and individuals) away from fossil fuels by the year 2050 — an ambitious goal he strongly believes is technically feasible. The book, Sustainable Energy — Without the Hot Air (UIT Cambridge, 2009), is available in bound form or as a free PDF download and is endorsed by such disparate players as Royal Dutch Shell and Friends of Earth. It is rapidly becoming essential reading for anyone serious about crafting reasonable energy policies.

MacKay’s idea is simple: To realistically examine energy policy alternatives, passion and hyperbole must be eliminated. Instead, only the numbers need add up for rational trade-offs between different forms of energy and conservation to be made. For example, if every inch of the United Kingdom were covered with wind farms, fossil fuel consumption would fall radically, he writes. But that’s not possible. How about 10 percent of the country, adding up to an area the size of Wales? That’s aggressive, McKay says, but doable. The problem is, such a project would contribute only about 5.5 percent of daily average energy use across the U.K.; in other words, a long way from solving the problem.

In similar fashion, MacKay explores the limits of each form of alternative energy — how many rooftops could be covered with solar panels and what could they produce; how many wells could be dug to draw out geothermal energy and how much energy they could generate. Then he stacks the answers up in a bar chart placed alongside another bar chart that shows energy consumption at current levels. The conclusion: Plenty of sustainable energy is available to replace fossil fuels without a major change in lifestyles. Recently, MacKay spoke to strategy+business about his novel ideas and the political, economic, and social will it would take to implement them.

S+B: What do you mean by hot air?
MacKay: Hot air is the twaddle that many companies, campaigners, politicians, and journalists emit when they are discussing how to solve our energy problems. Insignificant gestures are dressed up as “green initiatives,” as if they’re going to make a big difference. The latest example of that was in a recent newspaper article about a supermarket in England that is installing speed bumps to convert the motion from customers’ cars into energy; that’s supposed to power all of the checkout tills in the store. I did a calculation of how much energy you could plausibly get from an arriving car and it amounts to 1/4,000 of the energy used during the car’s trip to and from the supermarket, assuming it’s three miles [4.8 kilometers] to the supermarket and three miles back. This is just a tiny, tiny amount.

S+B: But doesn’t every little bit help?
MacKay: Not really. Say you’re trying to raise money for a hurricane victim and a million people each give one dollar. You would end up with $1 million for the one victim — so yes, in that case, all these little contributions add up to a lot. Not so with energy. The difference is that we all use energy; if everyone does a little and saves 1/4,000 of his or her energy use by driving to a green supermarket, it adds up to 1/4,000 across the board. You can multiply it up and make it sound big by saying 300 million people are doing it, but still all we’ve saved is 1/4,000 of the energy consumption.

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  1. David J.C. MacKay, Sustainable Energy — Without the Hot Air (UIT Cambridge, 2009): An examination of the fiction and truth about a carbon-free future.
  2. Business Roundtable Web site: A site for corporate leaders on energy policy.
  3. International Energy Agency Web site: An essential source for global energy statistics.
  4. Sustainable Energy — Without the Hot Air Web site: David J.C. MacKay’s sustainable energy blog.
  5. Sustainable Energy — Without the Hot Air Wiki: An open-source wiki based on the book.
  6. U.S. Department of Energy Web site: Official data about energy use, trends, breakthroughs, and concerns.
  7. WattzOn Web site: Among other things, a tool to quantify, track, compare, and understand your energy consumption.
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