Are you thinking about purchasing a generator to combat load shedding but are curious about how much it could cost to operate one? This article will examine the exact costs associated with operating a generator during load shedding, including

  • Factors that influence the cost of running a Generator?
  • How to save on Generator running costs?
  • Generator Fuel usage?
  • How much does it cost to operate your generator during load shedding?

This article will focus on the cost of fuel and does not include the cost of servicing and maintenance.

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Factors that influence the cost of running a Generator?

The cost of running a generator is influenced by a number of things. Let’s quickly review some of the factors that influence how much it costs to operate a generator:

  • Maintenance and service cost –  Generator maintenance will vary depending on how often you use the generator, the size of the generator and the type of generator. Please visit our Cost of maintaining a generator page.
  • The cost of fuel – The fuel consumption of your generator will vary depending on the size, fuel type, efficiency optimization and load on the generator.
  • Hours running – A generator will consume a certain amount of fuel each hour it runs thus the more hours you run your generator the more fuel it will use.
  • Generator working load – Generators are most efficient between 50% and 95% working load. Once generators operate below 50% they become less efficient and will use more fuel to use the same amount of energy. 

How to save on your Generator running costs

There are many ways to save some money on your generator operating cost lets have a look at some of them.

  • Only run necessities when running on generator power – Your generator will use around twice as much fuel while operating at 100% load as it does when operating at 50% load. This means that using the generator exclusively for lighting and necessary appliances can help you save a lot of money.
  • Opt for a Diesel Generator – Yes the initial cost of a diesel generator is double or triple that of the same size petrol generator but with a diesel generator using half the fuel you will quickly recover the difference in price and start saving money when the generator is used frequently.
  • Keep on top of maintenance and servicing – When properly and promptly maintained, a generator, like all combustion engines, is significantly more efficient.
  • Choose optimum size generator – When Choosing a generator, select a generator of the appropriate size, generators are the most fuel-efficient when operating between 50% and 100% load.
  • Opt for a high-quality generator – When buying a generator it is often wise to opt for a more expensive generator as brand-name, high-quality generators are better optimized for fuel efficiency thus saving you money, in the long run.

Generator Fuel usage?

For optimum fuel usage, it is important to select a generator of appropriate size and selecting a generator that is too big will increase your fuel usage by a large margin. In the table below we list some generator sizes with their hourly fuel consumptions under different loads.

Generator Size & Fuel TypeFuel per hour 100% loadFuel per hour 75% loadFuel per hour 50% load
3kVA Petrol Generator 1.8 l/h1.35 l/h0.9 l/h
5kVA Petrol Generator 3 l/h2.25 l/h1.5 l/h
7.5kVA Petrol Generator 4.5 l/h3.38 l/h2.25 l/h
10kVA Petrol Generator 6 l/h4.5 l/h3.0 l/h
15kVA Petrol Generator9 l/h6.75 l/h4.5 l/h
7.5kVA Diesel Generator2.0 l/h1.5 l/h1 l/h
10kVA Diesel Generator 2.5 l/h1.875 l/h1.25 l/h
12kVA Diesel Generator 2.9 l/h2.18 l/h1.5 l/h
15kVA Diesel Generator3.6 l/h 2.7 l/h1.8 l/h

The above figures are only an indication of how much fuel a generator will use and will vary from brand to brand and under different operating conditions.

How much does it cost to operate your generator during load shedding?

With load shedding on the rise, knowing your potential monthly operating costs for a generator of different sizes at various load-shedding stages can be helpful. All the below examples are calculated at 75% load for optimal performance.

Generator l/h 75%Fuel PriceMonthly Hours Stage 2Monthly CostMonthly Hours Stage 4Monthly Cost
5kVA Petrol Generator 2.25 l/hR23.560R3175.00120R6345.00
10kVA Petrol Generator 4.5 l/hR23.560R6345.00120R12690
15kVA Petrol Generator6.7 l/hR23.560R9445.00120R18890.00
7.5kVA Diesel Generator1.5 l/hR22.560R2025.00120R4050.00
10kVA Diesel Generator 1.9 l/hR22.560R2565.00120R5130.00
15kVA Diesel Generator2.7 l/hR22.560R3645.00120R7290.00

The above figures are just estimates and will vary between generator type and brand and if the generator is run whenever there is a power failure. 

Please visit our Cost of Buying and Installing a Generator and Cost of Maintaining or Servicing a Generator to find out more about what costs you might incur when running a generator.

Or alternatively, you can contact LocaL Pros and we can connect you with a leading generator expert in your area for some great advice on what generator to choose and how to run it optimally.

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