Page 9 - Green Builder Magazine Jul-Aug 2021

Most American Homes Now Rooftop Solar

Have Some Air Conditioning Could Be

Only 1 in 20 U.S. homes lack environmental control, Shared With
vs. nearly 1 in 2 in the 1970s.
Neighbors’ PCs
As of 2020, 95 percent of single-family residences had some type of air conditioning, up
from 46 percent in 1975, according to U.S. Census Bureau data and a report from home
remodeling site FIXR. The biggest lifestyle change came in the Northeast, where only Excess energy from a
13 percent of residents had A/C back when Gerald Ford was president. Fast-forward
45 years and that total rises to 89 percent. Meanwhile, the Western U.S. climbed from homeowner’s PVC system
29 percent to 86 percent. Distribution is far from uniform, however. Only 44 percent
of Seattle homes have any form of A/C. can be drawn off the grid by
The West’s growth in A/C use was largely due to increased unit availability and afford- other computer users.
ability, which helped bring people into areas that were too hot to live in year-round,
according to FIXR. Hot climate homes featuring second stories and windows facing Researchers from the Universitat Oberta de
the sun could now have their temperatures “mitigated with fresh, conditioned air,” Catalunya (UOC) in Barcelona have designed
the site notes. a prototype that allows a homeowner whose roof
Innovation has mitigated the additional energy demands of home cooling to some receives direct sunlight to install a photovoltaic
degree. Heat pump technology and more-efficient compressors have made possible system and become a potential supplier of
wider use of A/C without overloading power grids. computing power. According to a UOC release,
participants with the necessary physical
resources—such as computer hardware—
1975 can store excess energy for their own future
personal computing needs, or “inject it” into
the electrical grid.
Meanwhile, software installed on a potential
grid user’s computer can place their machine
in sleep mode and awaken the unit if there is
enough excess energy available, according to lead
researchers Borja Martínez and Xavier Vilajosana.
“Right now, the conditions are right to create
a critical mass of producers—the providers
of computing resources—and consumers, the
persons and businesses who could lease these
resources,” notes Martínez and Vilajosana.
A study on the project appears in the journal IEEE
2020 Transactions on Sustainable Computing. GB

Feeling blue.
Air conditioning
wasn’t a sure
thing in 1975, but
by 2020 much of
the nation had Sun sharing. PC-designated solar energy in
caught up with the residences can help people elsewhere power their
Southern U.S. computers, thanks to a new device from Barcelona-
SOURCE: FIXR AND U.S.
based researchers. CREDIT: MARUFISH/FLICKR
CENSUS BUREAU
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