An article taken from worldofrenewables.com, titled ‘feeding into the grid by going green’
A pair of Flathead Valley homes designed by a trio of young builders could soon begin making changes in the local energy grid
USA – Marty Beale, Jason Pohlman and Dave Radaiti, through their Evolution Homes business, first designed and headed up construction this summer of a straw-bale home in Pleasant Valley near the Lost Prairie skydiving field.
Now, the walls are going up at a second “green” home they designed to be tucked behind a field and in front of a stand of trees at the junction of Twin Bridges and Lodgepole roads northwest of Whitefish.
Both homes are plowing new ground with their energy-production systems that will feed at least some power back into the grid.
At the Lost Prairie home on Friday, solar panels that will produce a good chunk of the home’s energy needs — during sun-drenched months, probably more than its needs — were plugged into the Flathead Electric Cooperative grid.
Eventually, the “banked” kilowatt hours — that over-production from the sunny months — will be stacked against the home’s energy use in low-producing winter months, netting a lower electricity bill.
It’s only the second home so far to tap into Flathead Electric’s net metering program. The first, on Spotted Bear Road near Martin City, has been online just a couple of weeks, Flathead Electric Director of Energy Services Ross Holter said.
But Lincoln Electric Engineering Manager Jamie Stark said the home the crew is building outside Whitefish is on schedule to be the first to feed energy back to his cooperative’s power grid.
Going solar is a decision the three designers and builders came to as a matter of conscience and practicality.
“It’s only smart,” Beale said, sweeping an arm across the landscape on a crisp, sunny morning at the Twin Bridges home, where sawing and pounding served as his backdrop. The sun isn’t going away, he reasoned; its power is there for the using.
“You might as well work with all this around us and not shut it out.”
All three are college-educated. Radaiti studied sustainable housing issues, his lifelong friend Pohlman was in business and economics, Beale hit environmental studies and delved into government energy research documents as he studied off-the-grid homes.
They worked two years in construction on Nantucket Island off the Massachusetts coast, then five years ago headed west to Montana. They began by offering conventional siding packages for high-end homes, working as subcontractors through Mindful Designs, Inc.
They grew the business into a general contracting company with a green focus. In 2005 they formed their own environmental consulting business, Evolution Homes, to take a project from site design to the preconstruction phase.
“It’s ‘evolution’ because it’s just a matter of time,” Pohlman said. “We want to build smarter, build a better future.”
“The underlying idea is to make the project as green as the project allows,” Beale said.
A lot of that green ethic comes in with the initial site design, they said, fitting the home with the land and working on a tight team holding to the same ethic.
When the team got started on the Lost Prairie home, they signed up with a dream situation.
Rick Stern and Val Edwards own the home, which combines passive solar heating, solar panels and straw bale insulation. Stern once directed the Missoula Urban Demonstration project, a nonprofit formed to teach sustainable living practices.
Together, Mindful Designs and Evolution Homes worked out a photovoltaic system (converting light into electricity) with Stern and Edwards that they expect to make the home energy-neutral.
Holter said the Martin City home also uses a photovoltaic setup to feed power back into the Flathead Electric grid.
“We refer to it as net metering,” Holter said. “If they produce excess power over what they use with us, the meter effectively goes backward and they build up the credit” to apply the wattage toward future energy bills.
It’s the same idea at Lincoln Electric Cooperative for the Twin Bridges home.
Under its net metering policy developed last year, Stark said the co-op requires any generating source to be at least one- and no more than 10-kilowatt rated capacity.
“We saw this coming,” Stark said. “We said let’s be proactive and get this policy in place.”
Even so, Beale said, the home is pushing the envelope as design and construction move forward with the cooperative still developing software to handle the arrangement.
Photovoltaic energy production through capturing the sun’s rays helps avoid a massive battery bank where power is stored. Battery banks in general, Beale said, are one of the most expensive, least environmentally friendly and most maintenance-intensive parts of a self-powered home.
So the Twin Bridges home will use a minimal battery bank that goes into service only rarely, when the entire grid goes down. The infrequent recharge cycles will prolong the life of the batteries, he said.
It also is using a geothermal heat source system, pumping groundwater that is heated farther from the solar panels through radiant floor-heating tubes to heat the home. The geothermal system also raises the starting temperature for domestic water, requiring less heat to bring it to usable temperatures.
It’s typically more expensive to build power set-ups such as these two homes use, but a private solar consulting group is offering a small buy-back fee for those who feed into the power grid.
Combine that with the power-use offset from the two cooperatives, and people who are installing such systems begin to see a bit of monetary recognition for their efforts. It will take many years for it to pay for itself — the U.S. average for geothermal pay-back is seven years — but, Beale said, “we have unlimited storage potential without the need for any new waste, because we’re not creating any new storage.”
And legislation is forcing commercial electricity suppliers — cooperatives are exempt — to provide more of their power through renewable sources. Holter said in Montana the goal is 15 percent by 2015.
“We expect down the road our whole load growth will be augmented by solar systems,” Holter said. “Someday, if every house had a solar array on it and offset some of what they use, we would not have to provide so much new energy.”
The solar and geothermal systems at the Twin Bridges home are just part of an overall design to build it green.
Beale recited other green features there — 80 to 90 percent recycled material in the insulated concrete forms, higher concentration of fly ash in the concrete frost walls, passive solar through features such as window placement, and acid-washed concrete floors that absorb and release more of the sun’s heat, a pond that is part of the geothermal heating system and will be used for watering the horses and landscaping, roof-water runoff capture and reuse, wall framing that is two feet on center to use less wood, engineered lumber containing recycled material for the headers, insulating foam made with sugar beets, formaldehyde-free batts, insulation outside the framing to cut heat loss, gravity-fed water storage to reduce pumping needs.
The list goes on.
It’s a team of green-minded designers and builders working with a green-minded homeowner, a team that ultimately could serve as a demonstration of how practical green construction can be.
“We’re giving you a chance to move to Montana and not destroy what you moved here for,” Beale said. “It costs five to 20 percent more to build green. But think beyond five years, and it’s a question of what makes sense.”