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  • Eli is a contributing correspondent for Science magazine.
 

Texas = Energy Efficient?

21 October 2009 6:18 pm
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Results are out today from the American Council for an Energy-Efficient Economy's yearly report card of states' energy-efficiency policies. No surprise: California leads the way, same as last year. Overall, states are adopting better standards; the average score rose from 15 last year to 17 out of 50. But the main problem with the rankings is that they include few data on actual energy saved.

Until now. This year the council included a new effort to look at state-by-state energy efficiency by analyzing household energy use per person. The biggest surprise: Texas was second only to Washington state in efficiency improvement between 1997 and 2006, the most recent data. The results say a lot about making policies actually pay off—and how far the U.S. has to go to improve its energy efficiency.

The state efficiency performance data, which was not factored into thethis policies scorecard, looked at residential energy use per person. It's next to impossible to compare absolute amounts of per-person energy use between states because of differences in weather. Comparing chilly Wisconsin's per-person energy use to balmy Arkansas's, for example, may unfairly advantage the warmer state, not to mention economic differences. Richer states would also tend to use more energy per person than poor ones.

To get around these problems, the council looked at the improvement of states over a 10-year time span for per-person energy use. What they found was pretty "terrible," admits energy policy analyst Arne Jacobson of Humboldt State University in Arcata, California, who did led the analysis. All but six states of the 48 he analyzed, he told ScienceInsider, had become less efficient over the 10-year period that started in 1997.

But in Texas, the average person used roughly 200,000 BTUs less energy in 2006 than in 1997—roughly a day and a half's worth of residential energy consumption. (That may not seem like a lot, but Texas has 24 million people.) Texas's energy-efficiency policies on the main scorecard are much worse than California's—it scored a 16.5 out of 50 versus California's 44.5. But Texas and California improved by about the same amount in residential use over the 10 years.

So how did Texas improve so much while the rest of the country was sliding backward on energy efficiency? Jacobson's team is still crunching the numbers—and the data have yet to be peer-reviewed and published—but he thinks the reason is that Texas is building so many new homes as its population increases. The state has "only decent" building codes, he says, but the codes get enforced for new construction, which can lead to improvements in efficiency. (The same can be said about Nevada, which also scored highly on Jacobson's improvement ratings.)

By comparison, New York ranked fifth on the scorecard for its policies, but its citizens used 300,000 BTUs more energy per year in 1997 than they did a decade before—putting it at number 17 on Jacobson's list. Building codes are only one element of residential energy use—another important one, of course, is appliances—but although New York has more stringent building codes than Texas, there aren't as many new homes. So better codes have less of an impact.

The take-home message, says Jacobson, is that the U.S. has a lot of improvement to make: 42 out of 48 states were moving in the wrong direction as of 2006. But he feels that the steadily improving state policies should yield real energy savings in the future. That's why per capita energy use in California, with tougher efficiency laws, has remained flat, while the rest of the country's has gone up by 50% over the last 35 years.

And, of course, residential energy use is just one part of total energy efficiency. All told, European citizens use about half the energy U.S. citizens do.

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