Net zero homes – do the math

Gary and Bobbie Worker from Portland, had their heart set on an energy neutral home that was as financially-efficient, as it was ecologically effective. “We wanted it to make sense,” said Gary. “And we wanted to approach it from a standpoint of return on investment.” A typical family which clears its electric and water bill and uses an electric car to avoid filling up at the pump, will save more than $800 a month.

Their 2 acres outside Portland has an underground heat pump to heat their space. It also powers AC and ventilation. But they also have an electric car, which sometimes donates energy to the home and sometimes uses it, courtesy of the array of solar panels. At first, they used to see it as a backup power unit but increasingly they depend on the surplus energy it gives them when they drive it home at night after a day charging up in town.
And its proving a worthwhile investment.
Water is not a problem in the house which has no access to any utilities. The Workers have a 40,000-gallon water tank, more than enough, which catches the rain as it ;ands on their roof – its called a rainwater-harvesting system and provides water for the home and landscaping.

Their “net-zero” home, produces more energy than it requires, and should reduce utility bills to a few bucks a month, at least int he summer.
Their contracter says locals are approaching this subject as environmentalists but also as economists.One local has calculated that it will take only a few years for the investment to recoup itself, accounting for conventional utility bills, federal tax credits for solar and geothermal systems, investment in energy upgrades and the cost of adding more solar panels to charge an electric car verses gasoline for 2,000 miles of driving per month.

The federal tax credit is available through 2016 and gives homeowners a 30 percent credit for the cost of a geothermal system, solar array or residential wind turbine, as long as it is for a primary residence (and not a vacation or investment home).

Its unlikely the Workers will ever run out of water.After federal rebates, it costs a family an additional $42,000 on top of the cost of more conventional systems to invest in solar, geothermal, rainwater harvesting and other energy saving measures such as LED lighting.

And some of the cost might be tax deductible because interest on loans taken out can sometimes be reclaimed.

Like other off-gridders, he would like to see large builders create entire neighborhoods of energy-producing homes. “We need to take these houses and put them into production,” he said. “Sooner or later, it’s the math that’s going to work on that level.”