Net Zero Home

Net Zero Home

Solar panels were just “icing on the cake” for Jeff Herr when he designed and built his super-
insulated, passive-solar home in lower Rossland in 2010, but 4-kilowatts of photovoltaic icing
should tell you something about the cake.

PASSIVE SOLAR EFFICIENCY

“When we built this place, our goal was to make the best envelope possible,” said Herr, who
worked with his father to build his home with 12-inch walls, triple-paned windows, and lots of
“thermal mass” (such as polished concrete floors) to hold a steady, comfortable temperature all
year long. In summer, long eaves shade the south-facing windows and keep the floors cool. In
winter, the low sun streams in those same windows, heating the floor and filling the house with
light.

Passive solar — using sunshine to heat heavy objects in well-insulated buildings — is the
primary source of heat in Herr’s 1200 square-foot house. He supplements this with the heat
equivalent of a big pickup load of firewood. “The huge benefit of good sealing and insulation is
the comfort of the house,” Herr explained. “There are no drafts, no cold spots, and no hot spots.”

There are limits. “The most efficient design is a square building with no windows at all,” Herr
laughed. Even triple-paned windows are “basically holes in the wall” that lose more heat at night
than they gain during sunny hours. But few people, even the most energy-obsessed, care to live
in a box. Design decisions have to balance many needs.

LIFESTYLE EFFICIENCY

To that end, Herr steadfastly refuses to discuss “cherry on top” solar panels until he’s talked
about “the important stuff.” Typically half of a residence’s energy is spent on space heating, and
appliances and hot water each take another quarter. So, whether for a new build or a renovation,
Herr’s recipe is simple: seal and insulate your home as well as you can, and monitor your energy
use to eliminate waste.

Herr used to operate a solar installation business, but he spent most of his time convincing
people to prioritize basic insulation and energy savings before spending their money on panels.
It’s good advice, so good that he claims he talked himself right out of business!

“Most of us know the miles-per-gallon of our car,” he said, “but how many of us know the
kilowatt-hours-per-day of our home?” Herr started to save money the moment he installed a
simple “Neurio” meter to track power in his house, identifying a wasted 800-watt load and
helping to keep his day-to-day power consumption in check.

“It’s just like budgeting calories for weight loss,” he said. “You can see that, yes, turning off
your computer at night really makes a difference.”

SOLAR PANELS

Herr installed 18 solar panels to his south-facing roof and connected them to his electric meter,
spinning it backwards. For 8 or 9 months each year, the panels produce more than enough
electricity for his home, with extra power feeding the large basement workshop where Herr
makes his living bringing mechanical ideas to life. This summer, wildfires cut his solar
production in half on smokey days, and very cloudy weather can have a similar impact, but
Rossland’s typically clear skies make photovoltaics a winner.

Living with solar is easy. “Really, you have no idea you’re living in a solar house,” Herr said. “It
makes no difference. You only notice it when you open your Fortis bill.”

Tying into the grid avoids batteries or charge controllers, often the most expensive and short-
lived part of an off-grid system. Including installation, grid-tied homeowners can expect to pay
about $3.50 per watt, so a 4-kilowatt system comes to about $14,000.

Panels install easily on many kinds of roof, including asphalt like Herr’s. Standing-seam steel
roofs are another option that make installation a snap. Snow loads, however, are a major
consideration. “Get the max,” said Herr, who purchased panels rated to 113 pounds per square
foot.

Maintenance is simple too. Most panels are performance rated for 25 years and will probably last
much longer. Every 10 or 15 years, a replacement is likely needed for the inverter (a box-on-the-
wall that converts the panels' power into regular household voltage) but otherwise there’s not
much to do.

“I haven’t been up there since I installed them. I should be out there wiping dust off from all this
construction,” Herr said, nodding to crews installing pipes and pavement on his street, “but the
snow will do it this winter.”

That’s right, Herr doesn’t even clear snow off his panels. “It’s not worth the effort,” he
explained. “There’s more bright sunshine in September than in November, December, January,
and February combined. Just optimize your summer angle and forget about the winter.”

Herr has similar “keep it simple” advice for trackers, contraptions that turn like a sunflower to
face the sun. “People love trackers,” he said, “but if you used the extra cost to buy more panels
instead, you’d be ahead in energy production and have none of the trackers’ maintenance issues.”

THE ENERGY BUDGET

In the big world of energy efficiency, Herr keeps it real. “I wish those solar panels did more to
offset the trip I just took to New Zealand,” he laughed. “I’m as guilty as anybody doing whatever
the heck I want, and flying and transportation are a huge part of our carbon footprint. A big
carbon impact of this house was keeping me too busy to fly anywhere for four or five years while
I built it!”

Joking aside, Herr’s super-efficient building will have a substantial effect over its lifetime. In the
US, buildings account for half of all energy use, and Herr thinks its worth the effort to learn more
about our impacts, especially the energy we use day to day.

“Everyone should go online and calculate their carbon footprint,” Herr suggested. “We run
around in circles talking about climate change, but most of us don’t even know what we do or
how we contribute.”

– Article By Andrew Bennet