Alternating-current RAPS systems

Stand-alone diesel generators have been a popular choice in the past and can still be cost-elfective given the following (i) the load curve is relatively constant, i.e., the load factor of the diesel is kept above 50-70% (below this, the efficiency of the generator decreases markedly and maintenance costs increase, see Section 14.2.2)  

RAPS systems that incorporate a component of renewable energy generally require battery energy-storage. Examples of such systems, together with their application and associated service, are summarized in Table 14.1. 

Design B a renewable energy source, a battery, a controller, and an inverter. The renewable energy can be derived from a PV array and/or a wind generator and/or a hydro-generator. A PV-battery-inverter system is a common option in areas where insolation is plentiful. The capacity of such systems usually ranges from 0.5 to 2 kWh per day. Often, these systems provide a.c. power for household appliances as well as 

Design C a diesel generator, a battery, a controller, and an inverter. Such a configuration is useful in systems where high peak/base-load ratios are experienced (i.e., the majority of applications). This option is commonly used for sites with energy requirements that exceed 2 kWh per day, provided site access is adequate and maintenance and diesel fuel costs are reasonable. As the battery and inverter component can supply the load independently, operation of the diesel generator can 

Isolated homes with low energy consumption 0.2-0.5kWh per day 

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