Page 182 - Applied Photovoltaics

Their advantages include:
x availability of power on demand
x mature technology with service support usually readily available
x good output AC waveform with little or no distortion
x good voltage regulation
x can be used to charge batteries via a battery charger
x wide range of models available up to quite large currents
x good temporary overload characteristics
x low capital cost for the power produced.

Disadvantages

There are some major disadvantages to diesel-only power systems, which explains the
keen interest in RAPS systems. These disadvantages include:
x high operating and maintenance costs
x need for fuel delivery and storage
x noise (especially troublesome for night-time operation) and smell
x emissions of potentially dangerous exhaust fumes, which necessitates care in
siting, and of greenhouse gases
x need to be run near full load (80–90% of rated power) for maximum
efficiency (see Fig. 9.4) and reduced maintenance costs
x reduced efficiency for up to half an hour, until properly warmed up
x need for periodic operation, typically a minimum of four hours every two
weeks.

Figure 9.4. Diesel generator efficiency as a function of load.

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