Diesel engine powered electrical generators (diesel gensets) are used both for primary power delivery, and as a back-up supply that can deliver electrical power in the event of a mains failure. Good reliability, ease of maintenance, and abundance and relative cheapness of fuel mean that diesel generators are a common choice for these applications.
The decision to install a back-up supply will depend on the importance of maintaining supply during mains power outages. Mains failure can be a result of external issues with the grid, or could be faults within the consumer’s own electrical supply. The effect of an outage can range from being a nuisance to having significant implications with safety and revenue at risk.
For data centres, hospitals and other sites with critical applications, an emergency supply is clearly essential. At other sites, back-up power may still be required for safe evacuation or for firefighting.
Loss of revenue during outage, and the costs of process start-up, might be sufficient to justify the cost of a standby power supply. In addition, the loss of reputation for failed delivery, and the general nuisance to operations, can help to make a diesel genset an attractive option where power outages are likely.