A Quantitative Look to Energy Sustainability
Booz, Inc’s strategy + business has an interview with Cambridge University’s David MacKay about his recent book taking a quantative approach to energy sustainability: “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.”
“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.”
The executive summary of the book is available here.
What I advocate is that each country produce a road map, based on the consensus of, say, a group of 60 business leaders, engineers, and political leaders, for what actually adds up, what actually can be accomplished, respecting the laws of physics, the laws of economics, and the financial and political reality.
A few sacred cows skewered by Taylor:
Bad: Hydrogen-powered vehicles are a disaster. Most prototype hydrogen-powered vehicles use more energy than the fossil-fuel vehicle they replace. The BMW Hydrogen 7 uses 254 kWh per 100 km (while the average fossil car in Britain uses 80 kWh per 100 km).
Good: In contrast, prototype electric vehicles use ten times less energy: 20 kWh per 100 km or even 6 kWh per 100 km. Electric vehicles are far better than hybrid cars. Today’s hybrid cars, which are typically at best about 30% better than fossil cars, should be viewed as a brief helpful stepping stone on the way to electric vehicles.
Bad: Decentralized combined heat and power is another looming mistake. Yes, combined heat and power (that is, putting individual power stations in each building, generating local electricity and heat to keep the buildings warm) can be a slightly more efficient way of using fossil fuels than the standard way (that is, centralized power stations and local condensing boilers). But they are only about 7% more efficient. And they use fossil fuels! Isn’t the goal to get off fossil fuels?
Good: Heat pumps are back-to-front refrigerators. Powered by electricity, they pump heat into the building from the outside – either from the air, or from the ground. The best heat pumps, recently developed in Japan, have a coefficient of performance of 4.9; this means that using 1 kWh of electricity, the heat pump delivers 4.9 kWh of heat in the form of hot air or hot water. This is a far more efficient way to use high-grade energy to make heat, than simply setting fire to high-grade chemicals, which achieves a coefficient of performance of only 0.9.
Bad: Roof-mounted micro-wind turbines are an utter waste of resources. They never pay for themselves.
Good: In contrast, roof-mounted solar water heaters are a no-brainer. They really work: even in Britain, where the sunniness is only about 30%, a modest 3-m2 panel can supply half of a typical family’s hot water.
Bad: Turning phone chargers off is a feeble gesture, like bailing the Titanic with a teaspoon. The widespread inclusion of “switching off phone chargers” in lists of “10 things you can do” is a bad thing, because it distracts attention from more-effective actions that people could be taking.
Good: Turning the thermostat down is the single most effective energy saving technology available to a typical person – every degree you turn it down will reduce your heating costs by 10%; and heating is likely to be the biggest form of energy consumption in most British buildings.
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