An especially cold and snowy winter was no match for green energy this past year. The aptly-named net-zero energy test house is run by the National Institute of Standards and Technology in Washington, D.C. The house is used to vet various green energy implementation methods with the aim of establishing a model that would make utility bills a thing of the past. The experiment comes as the importance of green living is more evident and widespread than ever, largely driven by increasing brown energy costs and the effects of global warming coming home to roost.

The D.C. home reached its one-year anniversary at the beginning of July and did so with some startling results. Despite five months of below-average winter temperatures and two times the normal snowfall in the area, the virtual family of four living in the all-electric abode was able to end its year with 491 kilowatt hours of extra energy, which it exported back to the energy grid.

In fact, the home’s engineers may want to consider renaming it the “net gain house,” given how much energy it conserved. An average Maryland home, for example, would have required about $4,400 in utility bills to keep it running over the course of the year. The net-zero house saved that and then some, actually earning money in the form of rebates for its contribution back to the grid.

The challenge for engineers now will be figuring out how to roll out the home’s technology more broadly and affordably to the national market. There are heavy incentives to do so, as well, such as in California, where all new homes will be required to be net-zero-ready by 2020.

Fortunately, doing so shouldn’t be terribly challenging. The D.C. home was outfitted with many easily-implementable features, like LEED-certified energy efficient bulbs and appliances and affordable energy-generating features like solar water heating and a solar photovoltaic system.

All told, the house’s success holds great promise for green living across the board. Not only does it demonstrate how cost-effective sustainable buildings can be, but the costs it recoups can be used to pursue other green living implementations as well. A perfect example? The net-zero home’s energy surplus last year would have been enough to power an electric car on a round trip to Chicago, some 1,400 miles with energy left to spare.