Environmental Engineering Reference
In-Depth Information
Picture 15.1
A 10-kW wind power system at Kettle Foods in Beloit, Wisconsin.
Courtesy Kettle Foods, Inc.
The motor is coupled to a pump that has an efficiency of around 75 percent, which delivers to
the liquid at the pump outlet roughly 20 units. Then if flow control valve systems are in place
(
20 percent),
the fluid gets around 11 units of energy from the 100 consumed initially at the power plant.
Electricity is a high-quality form of energy because it can be transformed into any other
forms. However, at industrial and consumer levels, besides electricity, energy is also needed
as heat. For this purpose, fossil fuels are burned to produce heat for processes, hot water, or
buildings and household heating. If power plants would be more strategically located, the 66
percent rejected heat could be used for industrial and district heating purposes. A second
option that was covered in Chapter 11 is the on-site generation of heat and power, which can
produce mechanical or electrical energy and heat for heating applications with overall effi-
ciencies from 75 to 90 percent.
Chapter 11 presents several suggestions to improve energy efficiency of industrial processes
as well as several options for renewable energy. In areas of high solar insolation, even when
expensive, solar panels can alleviate the use of nonrenewable energy. Similarly wind power,
which is a proven technology, could be added to the mix in areas of steady winds. Other sources
of renewable energy include biogas from solid and wastewater fermentation and landfill gas in
the proximity of landfills. Additionally, the use of biogas and landfill gas solves the problem of
emissions of methane, which has a high global warming potential.
∼
30 percent losses), and if considering the loss to fluid friction inside the pump (
∼
Water
Water is an abundant resource on Earth, but only a small fraction of freshwater can support life
out of the oceans. Water is recirculated in the planet through the hydrological cycle. However,
water is a fast-declining resource because the use surpasses the rate of replacement. The most
