Page 96 - Piston Engine-Based Power Plants

CHAPTER 9 9

The Economics of Piston Engine Power Plants

The economics of power generation based on reciprocating engines
depends to a large extent on the use to which the engine is to be put.
Small electricity generators based on piston engines are relatively
cheap: for intermittent use these may be ideal but they are not designed
for continuous use and if exploited in this way will soon reveal their
limitations. As a backup generator for a domestic household or as a
portable source of electric power such a device may be ideal. For an
engine of this type, the up-front or capital cost will be the most
important factor determining choice.

Smaller engines that have been designed specifically for power gen-
eration tend to be much more expensive but equally much more reli-
able. These may be used for commercial backup systems in which case
reliability and capital cost are likely to be the deciding factors.
However many of these engines will also be used for distributed power
or heat and power generation. Some recent small engines systems are
aimed at domestic combined heat and power (CHP). The cost equation
then becomes a matter of comparing the cost of electricity from an
reciprocating generator to the cost of grid power, or to the cost of
alternative distributed generation technologies such as micro turbines.
The economics of a distributed generation CHP power system will be
different to those of a unit that is for power generation alone. The cost
of fuel will also begin to enter the economic equation.
Larger engines, of 100 kW or more, are often designed for base-load
applications. Such engines are expected to be able to operate round the
clock (but with regular maintenance intervention) for 20 years or more.
These engines are likely to be used in commercial and municipal institu-
tions as well as for industrial applications. Engines in this size range are
also suitable for grid support. Cost is high but the relative cost will
depend upon engine size. Larger engines tend to offer better economics
and lower unit capital cost. Fuel efficiency is important too and the
choice of fuel, and fuel cost, will be an important part of the equation.

Piston Engine-Based Power Plants. DOI: https://doi.org/10.1016/B978-0-12-812904-3.00009-4
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