Power generators: Which generator set for which application?

Whether it's a building site or a detached house, a farm or an event, electricity is needed almost everywhere these days. But what if there is no power connection or the power suddenly fails? In such cases, a generator can be a valuable aid: The genset's engine, which is usually powered by diesel, converts fuel into kinetic energy, which is then converted into electrical energy in the generator. This means that a genset can be used to provide electricity at almost any location.

Why is the right size of generator important?

The correct dimensioning of a generator is a decisive factor in guaranteeing a reliable power supply to a home or business. Generators that are too small in particular can become a safety risk: If the output of the generator is too low, it may not be possible to supply all appliances with power. In this case, forcing the generator to produce power beyond its load limit can lead to automatic shutdown or even overheating of the appliance - a worst-case scenario. However, a generator that is too large is not ideal either: both purchase and maintenance costs can be disproportionately high here and thus have a negative impact on the profitability of the power generator.

Which parameters are important for a generator set?

If you want to purchase a generator, you should first get an overview of which parameters are particularly important to consider when selecting one. Depending on the area of application and task for which the generator is intended, different requirements may be placed on frequency, voltage and power. For this reason, it is particularly important to find out which parameters the generator should definitely meet in use before purchasing a generator.

Which emission level does my generator need?

Generally speaking, there are often two different exhaust gas stages for power generators: Stage IIIa (3a) and Stage V (5). The emission stages regulate the amount of pollutants that may be emitted by the power generators. The higher the emission stage, the stricter the limits. This means that a generator with a Stage V emission level emits fewer emissions than a generator with Stage 3a.

Generators with emission stage 2/3a:

In Germany, stationary generators have had to meet the Stage 2/3a emissions standard since 2013. Generators with Stage 2/3a are therefore ideal for the emergency power supply of buildings, such as retirement homes or clinics, but also for agricultural businesses or for municipal connections. Exhaust gas aftertreatment is not as complex with Stage 2/3a as with Stage V generators in the same power class, which makes the price much more attractive. 2/3a generators are therefore an ideal solution for anyone looking for a stationary device with a good price-performance ratio.

Generators with emission Stage V:

Since 2022, non-stationary generators may only be produced with emission stage V - emergency generators that run for less than 500 hours per year are exempt from this rule. So if you are looking for a generator for construction sites, events or rental, you should opt for a mobile generator with emission stage V. However, exhaust gas stage V can also be useful for stationary use: Especially in environmentally sensitive areas (e.g. nature conservation zones or inner cities), Stage V emission level generators are more suitable thanks to their lower emissions.

Appropriate frequency: 50 Hz or more?

The German power grid usually operates at a frequency of 50 Hz - which is why the majority of gensets for the German market also supply this value. Generators with a frequency of 50 Hz are therefore ideally suited as emergency power generators for households or businesses whose appliances are otherwise supplied via the normal power grid. Anyone working with machines from abroad, on the other hand, should take a closer look at the rating plate or data sheet of their appliances. Devices from the USA or Asia in particular may require a power frequency of 60 Hz.

Voltage: 230 volts or 400 volts?

When planning an emergency power generator, the voltage is also of crucial importance. As a rule, a distinction is made between 230 volts (household current) and 400 volts (heavy current or industrial current). Most household appliances, lighting systems and smaller power tools run on conventional household current. For construction sites, agriculture and industrial operations, on the other hand, it is essential that 400 volt high voltage current is available to supply larger machines and systems. For particularly sensitive devices (such as computers, milking systems or automatic feeding systems), you should also make sure that reliable voltage regulation is available, as otherwise voltage fluctuations can cause damage.

Power: decisive criterion

The output of a generator is the parameter in which generators differ the most: Small generators, for example for camping, are available from an output of 2.5 kVA. Larger generators can have outputs of 750 kVA or more. How high the output of a generator needs to be depends in particular on the intended use: industrial plants need significantly larger generators than a single-family home. To define the appropriate output of a generator, you need to add up all the loads that are to be connected to the generator. At the same time, you need to consider which appliances will be operated at the same time and whether machines have high starting currents that require a higher output than in continuous operation. It is best to consult an expert to create a detailed load profile and thus select the optimum generator.

Operating time & location: perfectly matched

Two other important features that should be considered when choosing a generator are the operating time and the location for which it is to be used. For example, an emergency generator that is only intended to step in if the power grid fails at short notice may be designed for a shorter operating time than a generator that is intended to supply an event or construction site with electricity on a permanent basis. The ratio of fuel tank to consumption is particularly important here, as this determines how often the generator needs to be refueled when it is in use. Another important point is whether the generator is to be used as a stationary or mobile unit. Stationary appliances are particularly suitable for supplying power to houses, stables or industrial plants, as they often have a fixed location here. Although stationary appliances can often be transported with a forklift truck, the generators are not designed for frequent relocation. In this case, mobile or rental generators are more suitable: As they are designed for frequent transportation and relocation, they are ideal for construction sites, events or supplying power to emergency services in the field.