UPDATE at end of 2011 -- A decade's worth of energy produced in four years,
and still going strong.
Utility bills confirm that ten years worth of energy was produced by Suncroft House during the first four years of residence. These results were achieved for a family of four (including two teenagers), with no burning of any kind (wood, fossil fuels, etc.) The combination of energy efficient design, energy conservation in practice, and rooftop solar panel generation resulted in Suncroft House sending over twice as much electricity into the grid compared to what the house took from the grid.
Suncroft House continues to provide potable rainwater for all household uses during much of the year.
UPDATE (early 2010, after two years) – still achieving better than net zero energy!
Suncroft House, an all-solar net zero energy home in Eugene, Oregon, is producing significantly more energy than it consumes.
For 2008, electricity production was 271% of the amount consumed.
For 2009, electricity production was 273% of the consumption.
(This is more than twice the energy production required for a net zero energy home.)
These results were achieved for a family of four (including two teenagers), with no burning of any kind (wood, fossil fuels, etc.)
Energy data (verifiable from utility bills):
2008 -- 2113 kWh consumed, 5731 kWh sent into grid
2009 -- 2155 kWh consumed, 5896 kWh sent into grid
This extra energy could be used to power an electric car over 10,000 miles per year.
The net cost of the solar panels that make this possible is about the same cost as an SUV.
For the same budget as a conventional house of 1,500 square feet, a net zero energy home of 1,000 sf can easily be built (Suncroft House is 912 sf).
Potable Rainwater Update -- Zero contaminants
During the past two winters and springs, our family of four has used rainwater as our sole source of household water (for drinking, bathing, etc.) without any problems.
We have this purified rainwater tested for many contaminants (bacteria, mercury, lead, etc.), and the test results show no measurable levels for any of these potential contaminants.
In June our water storage level gets low, so we turn a couple valves to switch over to city water for the dry summer until the rainy season arrives again in the fall.