Net zero homes – do the math

Larry and Debbie - happy together
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.”

3 Responses

  1. Why is the above comment related to the Texas Hill Country but the location of the article in Portland Oregon? Did someone have a mistype? Also I think you should have your editor proof read the article before posting “but they also have n electric car” lol.

  2. To answer that question, Geothermal HVAC,can be installed in any part of the country. In the case of the Fulton’s home the bore holes that make up the heat sync are 300′ deep. After federal rebates for the system it is on par with a high efficiency heat pump. But the energy saved is 60-70% with a warranty that is 2-3 times longer. Another point not mentioned is that this system produces all the hot water for 7-9 months out of the year another savings. We have 5 more of these homes being built now,with a subdivision on the board. Homes as a generation station are here for good. This a green everybody believes in

  3. I agree that it is economics that is driving this for so many, myself included. It’s great that the house was designed to minimize energy usage…a critical consideration when you have to build generating capacity. I know of no easier way to make the numbers work. People who live in areas of the country with more consistent rainfall patterns could probably save a ton on rainwater storage. 40,000 gallons is huge, and necessary in no small part because it might not rain for months. What prompted the choice, and is the payoff there? Many thanks for an informative article.

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