California regulators have established an ambitious policy goal: Beginning in 2020, all new homes in the state must be designed for net-zero-energy operation. (GBA has published at least four news stories on California’s net-zero target: here, here, here, and here.)
At the recent Better Buildings By Design conference in Burlington, Vermont, the keynote address was given by Ann Edminster, an architect, green building expert, GBA blogger, and board member of the Net Zero Energy Coalition. Her presentation, titled “Zero: The Cinderella of Energy Efficiency,” focused on the growing interest in net-zero-energy buildings.
Edminster lives and works in the San Francisco Bay area. She dates the beginnings of the net-zero-energy home movement to 2000, but her chronology is a little generous. Although researchers were indeed discussing the idea of net-zero-energy homes in 2000, no one had successfully built one until late 2006. Before then, all of the so-called “net-zero-energy homes” used more energy than they produced.
In a July 2004 article I wrote for Energy Design Update (“Getting Down to Zero”), I reported that most of the touted “net zero” homes of that era used natural gas, propane, or firewood to provide some of the home’s energy, making no attempt to offset these fuels with electricity production. Of the two all-electric homes that self-identified as “zero energy” homes in 2004, one had a PV array that provided only 66% of the home’s electricity use, and the other had a PV array that provided only 20% of the home’s electricity use. At that time, the number of “zero-energy” homes that could demonstrate net-zero performance was zero.
In the pages of EDU, I announced a challenge. I promised to hail any builder, designer, or researcher who could provide 12 months of monitoring…