Tuesday, May 25, 2010

Zero-energy buildings: We have the technology

Last week Maggie Koerth-Baker from Boing Boing spoke with Kent Peterson, past president of the American Society of Heating, Refrigerating and Air Conditioning Engineers. This was a lot more exciting than it may sound. ASHRAE standards on energy efficiency end up written into our building codes, which means the organization plays a big role in influencing the shape of energy policy in this country. She talked to Peterson to find out whether zero net energy buildings—buildings that produce as much (or more) energy as they use—were really a practical goal. His answer might surprise you.
"We have studies that show [zero-energy buildings] are practical for approximately 62% of buildings in the U.S., based on technologies we have today," he said. "That's mostly one and two-story buildings and still leaves out a lot that can't reach it, but those buildings can be low energy.
In fact, Peterson said that currently available energy efficiency technologies alone (not even looking at generating power from wind or solar sources) could reduce the amount of energy used by the total U.S. building stock by 50%.

The catch: Hitting that 50% energy reduction goal—let alone getting to zero-energy buildings—means more than buying a better boiler. The environmental systems in buildings—the lighting, heating, cooling, etc—are already pretty efficient, Peterson says. When your heating system is 80% efficient, you can't get a 50% reduction in overall energy use by focusing on squeezing out the last few drops there. Instead, Peterson says we have to put more thought into reducing "plug load"—a fancy way of talking about all the gadgets and appliances we plug into sockets.

Think of all the stuff you leave plugged in all day. Like the microwave. It's nice having that clock function, and it really doesn't take much energy to run. But over the course of a year, all the electricity you used to run that microwave clock ends up being enough to power 30 hours of microwave cooking time, Peterson says. All the little "phantom" draws add up, and they bite us hard.

Automation is the muzzle. I've gotten pretty good about remembering to shut lights off in rooms nobody's using, but expecting me (and millions of Americans like me) to thoughtfully and correctly power down every electronic device they aren't using even half the time is about as unrealistic as expecting Anna Karenina to become the movie blockbuster of the summer. Instead, we can rely on "set it and forget it" systems that turn off unused devices while we're at work or asleep based on timers or occupancy sensors. Peterson already has something like this in his house.
"It's just controlled by my computer in my house, and it cuts power to specific outlets either by timer or click of a button. So I can cut power to my TV overnight, and automatically reduce phantom loads. That system had a bigger impact on my home energy use than all my other energy saving projects combined."


  1. Hello,
    My name is Arturo Uribe I live in Mesquite, NM. I live by these dairy's. I was looking for old pics of Tony Alva and came across your pics and found this website that has a letter you wrote to Tony Hawk about his Milk deal. I don't drink milk. My kids do when they have cereal but it's not a lot. I will probably be more cautious now because of the info you gave to Tony Hawk. I then just googled your name and found this post. It's amazing to me because we are working with folks from Sierra Club and with others on changing these codes and it's about going green and saving or using less energy. I know it's late but as I look at your pics I remember growing up listen to punk rock, rap, and skateboarding. Reading magazines and appreciating your pictures. Thank you. I am working hard with members of my community to make it a better place. Dairy issues are a concern but they have big time money and lobbyist. I was recently sued by a chemical company. I lost but I grew up never backing down from a fight. I'm appealing the decision. We have a hard road ahead of us but I appreciate how you put it. I was down and sometimes I want to give it up , but tonight you gave me a boost. I just wanted you to know.
    Arturo Uribe