Generator Cost per kWh Calculator

Work out what your generator costs to run per hour, and per kWh once you have a measured kWh figure, including fuel and maintenance.

Your results

The problem this solves

Many owners know what they spend on fuel but not what each unit of generator electricity costs. This calculator turns your fuel records into running costs.

How to use it

• Pick your fuel type and enter the price per litre you actually paid.
• Enter the litres used over a period you measured, and the running hours in that same period.
• Add measured kWh if you have it. This is the only way to get a defensible cost per kWh.
• Add a maintenance allowance if you want servicing included.

The formulas

• Fuel cost = litres × price per litre
• Total cost = fuel cost + maintenance
• Running cost per hour = total cost ÷ running hours
• Cost per kWh = total cost ÷ measured kWh

Worked example (illustrative)

Say the generator used 20 litres at an example price of ₦900 over 10 running hours. Fuel cost is ₦18,000, or ₦1,800 an hour, at 2 litres an hour.

If an energy meter showed 25 kWh over the same period, the cost is ₦18,000 ÷ 25 = ₦720 per kWh.

Why I do not guess kWh

A generator's kVA rating does not tell you the kWh it delivers. Output depends on the load. Without a measured figure, the calculator shows hourly cost only.

Limits

Fuel prices change, and engines burn more fuel under heavier load. Use records from a typical week. Ask an electrician how to measure kWh safely.

Related

• Deep Freezer Electricity Cost calculator shows what the same freezer costs on grid power.
• Inverter and Battery Sizing calculator helps you plan a backup that burns less fuel.
• How much does it cost to run a deep freezer? compares grid, generator and solar.

FAQ

How do I measure generator kWh?

Use a kWh meter on the generator output or your distribution board. Have a qualified electrician install it.

Is petrol or diesel cheaper per kWh?

It depends on the engine, the load and current prices. Enter your own records and compare.

Should I include servicing?

Yes, if you want the true cost. Spread service costs over the hours between services.

Results are estimates, not professional advice. See our disclaimer. Calculator and guide by Borniventure Ugochukwu Nwakamma.

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