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> particularly in the developing world where they can double as general electricity storage

I am from the developing world. I am middle class. I don't care much for general electricity storage.

I do care about a decent, low cost, 120 kM or so range car that is maintenance free.

This car, with around 9000 USD in price ought to be a game changer. The article states 30 kWH capacity for the battery.

A normal house in India is built in around 150 Sq. yards or about 1300 square feet. A 350 W solar panel costs about 12,000 Rs. (~180 USD). Assuming an average usable sunlit time of about 6 hours a day, it would take 14 such panels to charge the car fully.

A 12 V, 150 Ah battery (about 1.8 kWh) costs about 10,000 Rs (150 USD). To store 30 kWh, we would need about 16 batteries.

Since the range is about 120 kM, and assuming an average run of 60 kM per day (This is my actual mileage everyday, to and from work, and by most Indian standards, I am driving a lot)

Lets fix the total mileage covered by the car is about 200,000 km (60 km a day => 20,000 km a year => 10 years operation )

So, the car runs for two days, on a single charge. There are two ways, we can go about setting up a solar charger for the car.

1. Half panel Capacity, Half battery Capacity, Charge Daily

-> 7 x 350 W panels - Rs. 84,000 -> 8 x 12V, 150 Ah batteries - Rs. 80,000 -> System setup and mounting - 10% of cost, Rs. 16,000

Total cost : Rs. 180,000

2. Full panel capacity, Full battery Capacity, Charge once every two days.

-> 14 x 350 W panels - Rs. 168,000 -> 16 x 12V, 150 Ah batteries - Rs. 160,000 -> System setup and mounting - 10% of cost, Rs. 32,000

Total cost : Rs. 360,000

Choosing Option 1, Total car ownership & solar charging cost : 12,00,000 (~ 16,000 USD)

Now contrasting this to a petrol car.

Car Cost : Rs. 500,000 (Kwid petrol, AMT, Hyderabad) Petrol Cost: Assuming an average efficiency of 15 km / litre of fuel, and total running of 200,000 km and average price of Rs. 80 per litre of petrol -

Total cost of fuel itself comes to : Rs. 11,00,000

Maintenance cost : Rs. 0.3 / kM (Maintenance charges for my vehicle, averaged over 300,000 kM, between two cars, both from same company)

Cost for 200,000 kM -> 60,000 Rs.

Total cost of ownership of a petrol car : 16,60,000 (~22,000 USD)

The economics work out better if more distance is driven.

This EV model seems very much suited to India.

Actually for India the real electric car has already arrived and it is already seeing widespread usage. It costs less than $2000 and goes around 80kms on a single charge. It looks like a narrower auto rickshaw, most of them are manufactured locally and can be see used widespread in tier-2 cities in north india.

More details are at https://economictimes.indiatimes.com/industry/auto/auto-news...

Never heard of this before, but makes sense.

I would love an all weather three wheeler that is light and efficient to travel to work every day.

You'd install solar panels solely to charge your car? You have no other uses for electricity? And you'd be content to just let the power go to waste while the car isn't at home charging?

No, Nothing like that. I was focusing only on the car part. Of course, the 15 kWH solar system in your home could power the entire home too, or be fed back into the grid, which many municipalities in India are accepting.

Since I was doing a costing analysis, I assumed the worst case possible.

Accounting for selling power to the grid when not in use, usage for home, etc, the cost advantage of an EV improves even more.

Right so consider that you could also sell spare power from your car back to the grid when demand is high and you don't need to drive. Seems like another good benefit, particularly if the grid is prone to brownout (not sure if yours is)

From the car, I am not sure.

It is an appealing idea to use the car as a battery store, however, there are a few practical issues.

1. When using the car as a battery bank, we eventually increase the charge / discharge cycles of the battery, leading to quicker need for replacement. An external solar battery is cheaper, considering it need not be miniaturized. 2. When not in use, I'd prefer the car is charged, so that I can use it as and when immediately required, say an emergency. So, using power from the car, is not appealing, to me atleast.

3. Grid is prone to brownout in India, however, most cities and towns are experiencing it less and less and these are the major markets for EVs.

I think the implication is that it would be worth it to install battery backed solar panels purely to charge the car. Of course if you had an off grid solar power system you'd use it for lighting and other conveniences as well.

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