Single Generator or Paralleling Generator for Big Power Generator?

Buying A Single Generator Vs. Paralleling

If your power needs are large enough, you may wonder whether it’s better to go with a single, huge diesel generator, or split the burden between two or more smaller generators. For example, instead of a 1200kW generator, you could install three 400kW generators. This is called paralleling, and it can be a great option in the right circumstances. Here’s why:

1. Greater flexibility. It’s very likely the reason you’re buying a generator at all is the additional reliability, a hedge against an interrupted power supply causing a slowdown or halt to your business’s operations. With multiple generators, you don’t have to worry if one has to be shut down for maintenance. You simply shift the burden to the others and keep right on working.

 

With just one generator, if it has to stop, so do you.

 

2. Can be more cost-effective. Obviously the economics will vary widely depending on brands, new vs. used generators, prices in your geographic location, etc. But all things being equal, once you breach a certain generator size, it becomes more economical to parallel than use a single unit. Specifically, once you go over the sizes of gas or diesel engines mass-produced for use in cars, as well, those engines are harder to come by and are thus more expensive. And the engine comprises more than half the cost of a generator.

 

The threshold for diesel engines is 600kW and for gas engines it’s 150kW.

3. Can be more practical. Depending on your physical space, it may be easier to fit two or three parallel generators into a room than one oversized unit. Among large commercial generators, smaller capacities can mean the difference in 25 or more square feet per unit.

 

4. Easier on the generators. Load sharing among two or more generators can extend the life of each generator and avoid the risk of overburdening a single unit. For continuous usage, loads up to 80% generator capacity are ideal.