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What are the different applications for generators?

In very broad terms, generators (also known as gensets) perform two types of roles. Firstly, generators can be employed to provide electrical power at sites that do not have a grid connection. These are known as prime power generators. Secondly, they can be employed as backup units where there is a grid connection so that continuity of electrical power can be maintained when the grid fails. Gensets for backup are usually deployed where having electricity at all times is critical. Facilities such as hospitals, communication hubs, fire stations, and server farms are examples of such facilities. In a country like South Africa, backup gensets have become important for a much broader spectrum of power users due to the deteriorating reliability of the grid, which has led to frequent grid outages, both scheduled (load shedding) and ad hoc (technical failures). Prime power gensets are designed to run continuously and to accommodate variations in load. By definition, prime power gensets need to be more durable than standby units and have design imperatives different to standby units. For example, a prime power generator will need a far larger fuel tank than a standby unit will.

Generators – The Kings of Versatility

Michael Faraday’s discovery and description of electromagnetism led to his invention of a number of electromagnetic rotary devices that were the forerunners of generators and electric motors. He would probably be amazed at how ubiquitous and sophisticated modern generators and electric motors have become. Nikola Tesla, building on the work of Faraday, developed Alternating Current (AC), the standard for our modern technological society. The biggest advantage of generators is that they are incredibly versatile and adaptable sources of electrical power. Gensets generally consist of an engine and, on a unit designed to output AC power, an alternator. The alternator is what produces the electrical power when a mechanical power source turns its rotor. Power to turn the alternator can come from sources other than engines, including kinetic energy stored in water (hydro schemes), steam, wind, and wave or tidal energy.

Generators can be made in a vast range of sizes. The Three Gorges hydro-electric plant in China has the world’s largest generation capacity of any kind. It has 26 turbines, each of which produce just over 700 MW to produce a total output of 18,460 MW. According to Wikipedia, the largest internal-combustion-engine-powered generation plant is situated near Amman in Jordan. The plant is powered by 38 Wärtsilä 50DF multi-fuel engines with a combined capacity of 573 MW. On the other end of the scale is a tiny, efficient gas turbine, said to be the world’s smallest, developed by a research team at Tohoku University in Japan. The engine is just over 150 mm long and has a tiny 17 mm rotor inside which spins at up to 600,000 rpm. The power output is 2,6kW.

Due to the fact generators can be made to virtually any size, they can also be made portable. Gensets can be mounted to skids, shipping containers, trailers, trucks, trains, and ships. This allows electrical power to be provided just about anywhere.

Generators can be designed to output Direct Current (DC) or AC. They can be designed to output single- or three-phase power and three-phase units can be connected in two configurations, namely the Delta connection or the “Y” or “star” connection. In a Delta connection, the ends of the three windings join to form a closed loop, which looks like the Greek letter Delta. In a “Y” or Star connection, one end of each winding is joined together, leaving the other ends for connecting externally. This configuration looks like the letter Y or a star.

One of the phases of a three-phase generator may be used to supply single-phase loads, provided that the load does not exceed the power output rating for that individual phase. Certain gensets (ones with the reconnectable type ends) may be derated and converted from three to single phase, reducing the power output of the unit by approximately 30%.

Multiple gensets may be connected in parallel to provide redundancy or to increase the total generation capacity. Although it is possible to connect different generators together in multiples, it is better, and easier, to parallel identical generators.

Most generators will be able to output 50 or 60 hertz frequency AC by simply running the engine at 1800 RPM for 60 Hz output and at 1500 RPM for 50 Hz. There are limitations to which gensets this can be done with and specialist advice should be obtained before making any assumptions.

Strong Demand for Generators Will Continue

With the need for power outstripping the supply globally, the global diesel generator market is predicted to reach $21,37 billion in 2022. The fact that generators still provide far lower upfront capital cost and are far easier to deploy than renewable energy sources such as solar and wind, will continue to drive growth. Demand for gensets in the 1 to 350 kVA size range is particularly strong, accounting for around 49% of the market. Rapid global industrialisation in third-world countries in the Middle East, Africa, and Asia Pacific regions is expected to start driving up demand for larger capacity gensets suitable for use in mining, road and rail development, construction, and oil and gas processing. Emerging economies usually do not have sufficient grid infrastructure and grid capacity to power these operations which are often in remote, inaccessible, locations. An increase in demand for larger-capacity generators, in the 1000 plus kVa range, is consequently expected.

Choose The Right Partner

Regardless of your application, it remains critical that you engage with the right company when you decide to acquire a genset. PacB has an enviable reputation in the South African generator industry as a manufacturer of superior-quality, large three-phase diesel generators. Engaging with us at PacB will not only ensure the best outcome with regards to the cost, reliability, and durability of the solution but will also provide a one-stop experience, including design and implementation of the complete system.

PacB has years of experience in the industry and will provide expert advice on anything to do with gensets and power generation in general. The bigger and more complex the installation, the happier you will be that you engaged with PacB. The experience and expertise that a company like ours has allows us to help customers make fully informed decisions on the type of generator best suited to their specific environment. Leave questions like voltage and frequency, peak demand, harmonics, and total power required to the experts. Contact us at PacB today and get industry-leading products, advice, and service.