Page 36 - North American Clean Energy March April 2015

solar energy

Image 1. (Far left) he Wheelock
residence receives power from 36

mono-crystalline solar panels on three
passive solar trackers
Image 2. (Left) With the addition
of energy storage—from 16, six-volt,

lead-acid batteries—power outages
are a thing of the past

Figure 1. Wheelock’s annual power
production, with the addition of early
wakeup trackers

Living the Dream

Of net-zero energy & storage

By Mark Snyder

MILLIONS OF PEOPLE AND COMPANIES dream of never paying another electric bill. But for The road to net zero
most, the possibility of actually going net-zero remains unattainable, either because they Not one to back down from a challenge, Wheelock’s quest began with a comprehensive
don’t think it’s afordable or even possible.
energy analysis that revealed where power was going and where it was being wasted. his
Among the crowd of dreamers was Mr. Wheelock, whose 1800 square-foot home was approach helped assess and reduce the house’s power electricity demands before any major

built in the 1980s. Poorly insulated, the house had sky-high air-conditioning costs and energy changes or additional power sources were considered.
electric heating bills to match. Even in a dream, it was unlikely the house could attain At irst, older appliances were switched to Energy Star models, for example, and window
anything close to a net-zero goal, where the total amount of energy used by the structure awnings were added to block-out the summer heat. Eventually, Wheelock installed a
annually equals the amount of renewable energy created onsite.
solar water heater and solar attic vents, which have helped to keep the home cooler in

Beliefs aside, Wheelock was nothing if not determined. After paying ongoing high utility the summer. he biggest gains, however, came from upgrading the home’s ineicient air-
costs, there is one thing of which he became certain: “I don’t want another electric bill— conditioning system.
ever.”
Adding blown-in insulation boosted the attic’s R-value from R-19 to over R-50, reducing
heat losses and stabilizing the indoor temperature. Next, daytime heating was installed

to supplement the electric heating. Finally, a compressor-less air-conditioning alternative
HT Instruments America reduced Wheelock’s air-conditioning needs by nearly 90%. hese systems slashed total
electrical demand without sacriicing comfort.
Global leaders in PV Test
Diurnal (nighttime) temperature swings are key to this system. During the summer,
midday temperatures in the area hit 100° F (37.8° C). But they plummet to the 60s (far below
20° C) at night. hese temperature swings are common in coastal and mountain areas from
California up to Washington, as well as in Arizona, Nevada, Colorado, and New Mexico.

his simple ventilation/cooling system pressurizes the house to push in cool nighttime
air and drive out hot air from the house. Because the house drops to the lowest outside
temperature of the night, the building itself becomes a cooling system. During the daytime,
the house stays cooler because the attic’s solar vents, insulation, and cold air from the

night before prevent any heat buildup.
As a result, the system doesn’t have to cool incoming air with power-hungry
compressors—it only brings in pre-cooled air—eliminating 90% of air-conditioning needs
by using just 700 to 840 watts of power.

At this stage of the eiciency upgrades, Wheelock’s overall electric usage was down
almost 50%. But, he wasn’t done. To reduce the amount of heating done by the house’s
electric heat strips, daytime hot-air heating was also installed for the winter months. he
system delivers enough warm air on sunny days to heat the whole home.

HT Instruments is now offering the most complete line of quality • IV Curve tracers starting at $3,495
Moreover, the compressor-less cooler system is capable of reversing the direction of its
PV Test Tools for Installation, Auditing, Troubleshooting and • Installation Testers at $1450
airlow to also work during the colder months. Even on winter days, the air is often warmer
Performance Monitoring. Our products are speciically designed • Power Quality Analyzers starting at $4,995 during the day and colder at night. Although technically a cooling device, the system can
for the needs of the PV Professional and deliver QUALITY (with a pull in the warmer daytime air from the outside, warming the house to 70° F to 75° F (21°
3 year warranty!), ease of use as well as affordability.
• .adding more to the affordability promise
C to 24° C), and reducing nighttime heating needs.
he PV system gets its power from 36 mono-crystalline solar panels on three passive
HT Instruments America
solar trackers. And, the grid-tied system sells back additional power.
After this irst project, the Wheelock residence was net-zero for 2009, 2010, and 2011.
[email protected] | http://www.ht-instruments.com
732-952-2111
But, after adding a welding studio to his home (he’s an artist who does metal scroll work in
wrought iron), Wheelock was about to lose this status and have electric bills again, unless
he generated more power.

36
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