Energy and Changes in the Environment - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 64

Impact assessment requires knowing which materials, processes,
or components may be toxic and their impact on the environment and
health which varies according to the amounts involved. Disposable or
rechargeable batteries require weighing performance (battery-charge life)
against toxicity.
More companies are incorporating life-cycle costs and life-cycle
assessment into their operations. The U.S. Air Force has developed a
computer-aided software-engineering tool, for defining the complex sets
of interacting activities in the life cycle of an aircraft.
LCA emerged to analyze the manufacturing of toxic chemicals,
but now it even affects electronic and other manufacturing sectors. The
energy-efficient Green PC is an example. Computers account for about 5%
of all commercial energy in use today, and this could soon double. Standby
or idle power for some products like telephone-answering machines are
greater than the power consumed during operation.
LCA encloses the entire life cycle of a product from raw-material
extraction to end-of-life management alternatives including landfilling,
incineration, and recycling. Customer use of a product is a major
contributor to smog, nitrogen oxides, acid rain, and carbon-dioxide release
all stemming from a product's energy consumption.
In one study of the energy consumption of a portable telephone,
the energy spent in production was found to be greater than lifetime
use. The energy expended in production included that required for not
only material transformation but also the energy needed to keep workers
comfortable such as heating and air conditioning.
Hewlett-Packard and Xerox are recycling their hardware in Europe.
Xerox reprocessed copiers yield 755,000 components (51% by weight), and
recycled 46% by weight into reusable materials. This left only 3% of the
parts for disposal. All plastic parts should carry recycling symbols and
making parts from fewer material types and reducing paint, platings, and
screws can also aid in recycling.
Replacing older inefficient electricity-generating plants with much
more efficient new plants could save large amounts of energy. Some of the
older plants lose two-thirds of the heat energy as waste heat at the site.
Replacing these plants with those with more efficient boilers, controls and
turbines would reduce the lost of heat energy to about half. The plants
could also switch from coal to natural gas which could greatly reduce acid
rain problem while cutting CO 2 emissions in half.

Automobile emissions are being decreased with improvements in the