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.
The table above clearly shows having a dedicated LT6 connection results in overall lower cost even if house consumption is very low at 40 units per month. Indeed the difference only gets larger if the house consumption is larger. Extrapolating the same trend to increase our car usage, the delta gets larger as well. In summary, higher the consumption lower is the price for us with the dedicated LT6 connection. Ofcourse there is an initial cost for getting the new connection, but there will also be an initial cost for enhancing the existing connection's sanctioned load - deposit for the additional 8kW sanction plus the new meter. My electrician estimated that the cost would not have been less than 30,000 for it. So, the difference of 5,000 would be broken even in 10 months. Assuming Bescom continues to have the same pricing and rebate for LT6c.
To understand these numbers a little more, below is how I arrived at them. The first table below is calculating each of the fixed and variable cost for a 10kW sanction load. Fixed cost is the same throughout since its dependent on the sanctioned load (100 for first kW and 110 for each thereafter). Variable cost or energy consumption cost increases based on slabs and hence it can be seen increasing exponentially.
The second table below is the same view but for two connections - The existing LT2 for home use and the LT6c for car. Variable or energy consumption cost is the same for LT6c as there are no slabs for LT6c connection. Its a flat rate of Rs5 per unit.
Process of getting the separate LT6c connection
My electrical contractor did it very easy to get the connection by taking care of most of the leg work necessary. The only amount of work I did was an initial enquiry at the Bescom office to get the connection. I was told by someone that the LT6 connection is only for commercial uses. Then a friend at Bescom informed me about an amendment circular (
link) which showed that Bescom would give it for individuals too. I then contacted Arasu, my electrical contractor, and asked him to do the necessary work. He called me at frequent intervals to obtain the necessary documents such as my existing Bescom bills, house floor plan and to get the signatures. Then, once it was sanctioned he gave me the papers requesting deposit to be paid. I got the DD from bank. He then took care of rest of the work to do the wiring as per specifications given by the charger company, get in inspected and approved all the way until writing the RR number on the new meter. I am completely happy with Arasu and would recommend him to anyone. I am sharing his number below.
Arasu - +91 98451 42475
I am yet to get my first bill on the new connection, but am confident it will match my calculations above. Unless Bescom changes their tariff and removes the reduced pricing on LT6c, I will be able to have a low running cost and overall lower cost.
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