Environmental Engineering Reference
In-Depth Information
At the plant gate:
33 units
Conversion losses:
66 units
Transmission and
distribution
losses: 3 units
Consumed by power
plant: 1 unit
Power plant fuel:
100 units
Energy delivered to the
fluid after valve:
14 units
Delivered to the fluid
at the pump outlet:
20.25 units
V
P
M
P
L
Delivered to
customer:
30 units
Effectively delivered
to the fluid: 11 units
Factory
M: Electric motor, 90% efficiency
P: Pump, 75% efficiency
V: Control valve, ~30% losses
P
L
: Pipe losses: ~20%
Figure 15.2
Energy losses from power generation to final delivery to a fluid in a typical pumping
system.
large areas to grow; and needs a long times to develop. From the solar-energy-capture point of
view, solar panels are much more efficient than plants. However, solar energy capture is effec-
tive only when the sun is shining and massive accumulation devices are not available.
The reality is that now there are no technologies available to substitute for the declining
carbon-based sources as a whole. Short-term remedial actions are conservation, optimization,
and use of the few renewable energy sources that are available.
Energy is wastefully transformed and used today. Electricity, for instance, when produced
by burning fossil fuels has a conversion efficiency between 30 and 40 percent. This means that
between 30 and 40 percent of the energy contained in the fuel is transformed into electricity
and the rest is lost as heat to the atmosphere. And losses do not end here. In addition, some of
the energy generated is used by the plant and then there is transmission and distribution losses.
Figure 15.2 illustrates the journey energy takes from a typical power plant to a pump system
in a factory. For every 100 units of energy contained in the fuel, 66 are loss as heat during
conversion into electricity and 1 unit used by the plant, thus leaving 33 units available at the
power plant gate. From those 33 units, 3 are loss to transmission and distribution, therefore,
delivering just 30 units to the customer. At the customer facility, an electric motor takes the
electricity and converts it into mechanical work with a loss of conversion of around 10 percent.
