Users Guide to off Grid Energy Solutions

What is Generating Sets - Gensets


Generating sets supply more off-grid electricity than all other sources of off-grid generation combined. Generating sets (commonly referred to as "gensets" and in North America as "gennys") are usually powered by either diesel fuel or petrol/gasoline. They are usually rated in either kVA (kilovolt ampere) or horsepower (HP), although some people refer to the power rating in kilowatts (kW).

Gensets range in power from the smallest, a couple of hundred Watts, to very large, e.g. 10 MW. What characterises a generating set in common usage is that a genset is portable. That is, it can be moved from one place to another. While the concept of moving a 10 MW genset stretches the definition of "portability", gensets usually can be moved, and are generally not built permanently into a structure such as a power house or station.

The smallest systems are simple machines that are air-cooled, and should not be run as base load (i.e., to generate electricity around-the-clock). The smallest units are petrol/gasoline-driven, and operate at high rpms (rotations per minute). They get hot very quickly, and, if operated frequently, or as base load, their lifetimes are very limited (perhaps in terms of months).

Diesel generators are generally more robust pieces of equipment. Diesel gensets have been built and operated all over the world for most of the 20th Century. They can be found virtually anywhere in the world. Some of the world's best-known diesel genset manufacturers (or companies that now own them) have supplier networks all over the world.

Diesel gensets provide the advantages of ease of operation, ease of repair, generally plentiful spare parts, and an army of technicians and mechanics who can operate them and repair them. This explains, in very large part, why gensets are so popular. They are also almost always "off-the-shelf" (i.e., can be purchased without special ordering), and can be shipped anywhere in the world. Industry analysts estimate that, in Africa alone, over 100 MW of gensets are purchased each year, while in Asia, the figure is closer to 300 MW. They are doubtless one of the world's preferred off-grid electricity solution, and they are more often than not integrated as back-up electricity supplies for larger PV and wind electric systems.

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