Once we bring our EV car home, the next logical task is to get a charger installed at home. In most cases the sanctioned load in our home may not be sufficient to meet the needs of the car charger and hence we will have to enhance the sanction and change the electricity meter along with it. Thankfully for those of us in Bangalore, Bescom has a special tariff plan - LT6 which offers electricity at a flat & lower rate for EV owners.
Like most EV owners, I too got a 7.2kW charger. The sanctioned load on my existing connection was just 2kW. So I had a choice to enhance the existing load or take a separate LT6 connection. I decided to take a separate LT6c connection and in this post I am sharing my analysis of the difference in cost between the two decisions. Getting the separate connection costed me about 35,000 in total including the deposit, new meter charges, material etc. Further below, you will find the process I went through for getting the connection as well as contact info for my electrical contractor who did the job for me. But first, the math to see if a dedicated LT6c connection is worth it.
Price comparison:
Enhancing the existing connection means a single connection of 10kW, which is 2kW for existing house load plus a 8kW additional load because of the charger. Although it might be possible to enhance the load to 8 or 9kW in total, it will mean you have to shut off all major home appliances such as heater or A/C when charging the car. Hence I was recommended to enhance to 10kW and that is what I am using for calculation. The fifth column in below table '10kW LT2 connection' is representing this number.
The fourth column 'Lt6c dedicated + current Lt2' represents the total cost incurred by both the 2kW home connection plus the LT6 dedicated connection.
To make the comparison close to real life, I am making the following assumptions :
- Car usage of 25kms per weekday and 25kms over the weekend. This would all be city usage which will require charging at home. This translates to 150kms per week or 600kms per month.
- Economy rate of 6km/kWh which is an acceptable average I have seen when driving within city traffic.
This translates to 100kW or 100units consumption per month for charging the car. House consumption column in the table below shows various consumption levels and reflects what we see in our bill. The number would naturally be higher in summers and lower in winters. But the idea is to get an idea across the board.
I have used the slabs and pricing published by Bescom here, to do the below calculation and also verified the math against our last few months bills to ensure the calculations are correct. I have also included FAC charges applied by Bescom (fixed per unit cost) but have not added taxes.