During the first six months in their special, new, four-bedroom home in suburban Maryland, the Nisters, a prototypical family of four, earned about $40 by exporting 328 kilowatt hours of electricity into the local grid, while meeting all of their varied energy needs.

Furthermore, these virtual residents of the Net-Zero Energy Residential Test Facility (NZERTF) on the campus of the National Institute of Standards and Technology (NIST) didn’t have to skimp even a bit on any of the creature comforts of 21st-century living. Their amenities ranged from indoor temperatures maintained between 21.1°C and 23.8°C (70°F to 75°F) to a complete array of modern-day kitchen and laundry appliances, and from personal computers, a video gaming system, and two TVs to a pair of stereos, a hairdryer, and curling and clothes irons.

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