Page 3 - GB Building Science Ebook 2019

SOLAR PANELS

NEEDED FOR HOME

TO ACHIEVE ZERO

ENERGY

Avg. Estimated Premium
System
Ach Annual Kwh Number of Panels
Size
Production Solar Panels Square Ft.
.6 3.5kW 4,954 14 160
2 5 kW 7,161 20 224

3 7kW 9,909 28 330 SOURCE: HTTPS://NEWS.ENERGYSAGE.COM/HOW-MANY-SOLAR-PANELS-DO-I-NEED
3.6 10kW 12,165 40 448
4.5 12kW 16,987 48 540
5 15kW 21,234 60 672
Note: Based on average U.S. home, or annual demand of 12,000 kWh.

No Contest. Given that most new homes are built in the 5 air
changes per hour (ACH) range, you can see the added value in a net
zero home (2 ACH or better). You can heat/cool and power the
entire home with a solar array one-third the size.

IMAGE SOURCE: CITRUS COUNTY CHRONICLE (CHRONICLEONLINE.COM) optimizing envelope tightness. This foreshadows the fact that we’ll

be using renewable electricity for heating, cooling and every other
mechanical function of the home.
The fact that living in a zero net energy (ZNE) home is a good
Florida Awakens. After decades of resistance to
solar energy, the Sunshine State is going all in. This investment and a necessary step toward curbing C0 2 emissions
site near a nuclear power plant in Crystal River will doesn’t guarantee that they will become the new normal. But other
field hundreds of PV panels, producing 150 forces do. These include a vast labor shortage, a rapidly tightening
megawatts of renewable energy. code landscape, and, as mentioned above, the frightening effects
of Climate Change in the form of wildfires, extreme heat, monster
storms and so on. We’ll touch on many of these factors in this
special building science update, from the editors of Green Builder
HE PRICE OF SOLAR PHOTOVOLTAIC PANELS magazine, and Codewatcher.us.
has now dropped to a price lower than any fossil The age of “nothing but ZNE homes” is just around the corner.
fuel, including (in most regions) natural gas, and California is leading with Title 24, plus a new solar mandate and
solar’s rise from an early adopter experiment other regulatory changes. But many other states—plus the large code
to our primary source of global power seems agencies— have similar trajectories.
imminent and foregone. Unless scientists make Result: new products; new ways to increase the performance
a stunning breakthrough in nuclear fusion, no of old products, and frankly, a new, more urgent attitude from
other power source seems likely to outpace it. And municipalities and planners. “Sure, you can build it,” they’re
Tanxiety about Climate Change will only increase starting to say, “as long as it’s net zero.” Before we jump into some
the attractiveness of a rapid solar conversion. specific construction products and details that illustrate the sea
What this sudden price parity has done in the building industry, change toward ZNE, let’s look briefly at the current labor shortage,
when you connect the dots with a few other factors such as codes and how it too has played a role in innovation and change in the
and labor, is steer all aspects of future housing performance toward industry.

BUILDING SCIENCE SPECIAL REPORT: SIX WAYS CONSTRUCTION IS CHANGING 3