Exporting Energy in the Rockies

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The Lovinses' new house/office includes an array of state-of-the-art technologies. The result?

What sort of house do you build when your profession and passion is convincing people that energy efficiency and renewable energy sources can help cure our ailing economy, remedy a host of environmental ills, right social injustice, and make people happy? One that proves the point, of course. Which is just what the home/office/indoor farm of Amory and Hunter Lovins does. (The Lovinses are the subjects of this issue's Plowboy Interview on page 16.)

Today, even though the energy systems aren't complete, the building's performance already indicates that it is one of the most efficient in the world. With R-60 ceiling insulation, R-40 walls, earth berming, extensive R-5.3 glazing, an integral solar greenhouse, and a natural air infiltration rate of fewer than 0.2 changes per hour, the massive, super insulated structure has no need for auxiliary space heating. Indeed, Hunter and Amory describe their home's design as more than 130% passive solar, meaning that it's intentionally configured to receive, capture, and store more solar input than should be necessary to heat the structure completely.

In their view, it's better to vent heat than to run short. The wisdom of this overkill approach became apparent last fall, when Hunter, Amory, their dog, Nanuk, and several staff members of the Rocky Mountain Institute faced weather conditions that were unusual even for 8,900-degree-day Old Snowmass, Colorado. During a 39-day period in the late autumn, while they were still closing in the dwelling, they saw only three hours of sun, and temperatures ranged from 10° to -40°F. Despite numerous holes yet to be plugged, they were able to keep inside temperatures in the 50's and 60's by operating two woodstoves a third of the time. And once the building was sealed up and the roughly 1,000,000 pounds of cold-soaked masonry began to warm and dry, they were able to stop firing the woodburners. By the first of January, indoor temperatures held between 65° and 70°F, and the warmth evenly permeated the draft-free structure.

Eventually, as the time and money become available and technologies mature, enough solar equipment will be installed to make the Lovinses' 4,000-square-foot home and operations center for Rocky Mountain Institute a net energy producer. (It's already the sort of building that Amory describes as a habitable oil well, saving the equivalent of half a barrel of oil a day.) Even in the month of January, they'll have kilowatts of excess heat to offer perhaps to neighbors-for space heating. And photovoltaic panels will supply all of the building's meager electrical requirements. Think about it: Their house will actually be able to export power!