Calculate how long it will take to cover the cost of replacing your diesel generator with solar.

It generally only takes 1-3 years of diesel cost to cover the cost of your solar system which will last you 10-25 or more years, saving you a lot of money and hugely helping the environment.

Simply complete the form below with details of your generator, usage and diesel costs to get an estimate.
If you are then interested in swapping to solar please email and we will be glad to spec out a system suitable for you. Smaller systems you may find we have a kit on the website of a size that is suitable for you, and larger ones we will probably need to design for you. We are happy to work to a suitable budget to suit your needs.

If you are unsure of your diesel usage you can use this chart to approximate it.

If your generator is 5Kw or less then you might be better to use our Solar Calculator to estimate the power you require as it you may well require a much smaller cheaper system.

Victron ‘how to calculate genset size’

The table below automatically re-calculates when you edit a value. You can use any currency, just use the same currency for all values and remember to convert the solar per watt budget to the currency you are working with.

Generator details:
Generator size in Kw
Cost per Litre of Diesel
Litres used per day
1 Gallons (US) = 3.78541178 Litres
1 Gallons (UK) = 4.54609 Litres
1 drum = 208 Litres
Hours per Day Generator runs for
Percentage load generator running at
Approx average % load generator is usually running at
% load and KwHrs will alter each other, you only need to enter one based on the info you have available.
Approx KwHrs per day being used
If you know the actual KwHrs per day used then adjust the % generator running till this is correct.
Percentage of Power used during Daylight hours
Approx % of 24hr power consumption used during daylight hours
Diesel cost per month
Diesel cost per year
Tonnes of CO2 emissions
Solar System
Overspec Percentage
Overspec to allow for cloudy days or winter periods. You many not need to overspec as you still have the generator which can be used as a backup when the batteries are low.
Solar System Size in Kw
(estimated by % of power used by day)
Or you can edit to set the size you want.
Budget Cost per watt
From the table above enter a budget cost per watt that you think is suitable
Estimated cost of Solar system
Time to cover cost
Cost saving over 10 years
saving over 25 years
Tonnes CO2 Emissions saved 10 years
Tonnes CO2 Emissions saved 25 years

This is just a simple Calculator to help you estimate the move from a diesel generator to solar. A full system will need to be spec'ed if you would like to proceed.