Environmental Engineering Reference
In-Depth Information
year, and the difference between a vehicle that gets
miles per gallon of fuel and one that gets
mpg
amounts to about
gallons per year. When gas was
$
.
per gallon the cost difference was
$
. It is even
more signi
cant to the economy as a whole. The total
miles traveled in the United States by light vehicles in
were about
trillion, and for that the difference
between the
mpg and
mpg vehicle
eet amounts
to
billion gallons of fuel. At
$
.
per gallon that
amounts to
billion.
In buildings the situation is very different. It is dif
$
cult,
sometimes impossible for the individual to
nd out what
the savings might be from more ef
cient systems. Often
the savings for the individual are small while the savings
for society may be large in both cash and greenhouse gas
emissions. Here is a sampling from the APS report [
]on
barriers faced by consumers, manufacturers, builders, and
designers of products to making them more energy
ef
cient.
Not knowing: You may know your total utility bill, but
you do not know the contribution of each device that
uses energy without some sort of required labeling
system.
Not caring: If the energy saving is small enough, the
individual may not care about its cost. In
TVs used
a standby power of about
or
watts. Over a year that
amounts to about
$
.
worth of electricity per TV,
but over the
hundred million TVs it amounts to
$
million tonnes of greenhouse gases
from our present mix of electricity sources. The new
standard set by the federal government will be
.
billion and
watt.
