To make a rough estimate of the payback period, you can consider the following aspects:

1. Investment: The total cost of the charging station, including purchase, installation, and any additional costs such as network enhancement and cabling.
   
   

2. Charging behavior: The expected charging behavior at the charging station, including the number of charging sessions per day/week, the average charging time, and energy consumption per charge.
   
   

3. Rates: The energy rates applicable to charging electric vehicles, including the cost per kilowatt-hour (kWh) and any subscription or service fees.
   
   

4. Feedback: If you have solar panels and feed surplus energy back into the grid, this can shorten the payback period of the charging station, as you can use the generated solar energy to charge your car.
   
   

5. Subsidies and tax benefits: Possible subsidies or tax benefits applicable to the purchase and installation of the charging station, such as the Emission-Free Business Vehicle Subsidy Scheme (SEBA) and tax deductibility of investments.

It is important to note that the payback period is highly dependent on the individual situation and that calculating it can be complex. It is advisable to conduct a detailed cost-benefit analysis based on your specific circumstances to get a realistic estimate of the charging station's payback period.

Additionally, it is useful to consider the long-term benefits of a charging station, such as reducing dependence on fossil fuels, lowering maintenance costs of electric vehicles, and increasing the value of the home or business premises.