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Tesla About To Start Battery-Swap Pilot Program
cartechboy writes: Remember 18 months ago when Tesla promised it was going to launch battery-swap stations? Well, it's finally happening, sort of. It seems Tesla's about to announce a battery-swap pilot program that will launch next week. The swap site will be located across the street from a Tesla Supercharger site in Harris Ranch, California — 184 miles south of San Francisco and about 200 miles north of Los Angeles. The pilot program will involve an unspecified number of Model S electric-car owners, who will be invited to take part in the test. For now, the battery-swap service will be offered by appointment only, at a cost of roughly a tank of gas in a premium sedan. Tesla's using words to describe this pilot program like "exploratory work" and "intended to test technology and assess demand" for a swapping service. While originally pitched that the battery swap would take less time than it would to take to refill the gas tank of a comparable luxury sedan, the company says now that "for this specific iteration" the swap process will take "approximately 3 minutes" — though it adds Tesla has "the ability to improve that time with future iterations." Is this test going to show that battery swapping is or isn't a realistic initiative?
Ah, to be young and full of made up numbers. Let's do the math.
The large Tesla battery is 85kWh. A solar cell typically has an efficiency of 10-20%, so with about 5kWh/m^2/day of typical solar radiation (check PVWatts for specifics in your town you can produce about 0.5-1kWh/m^2 per day.
If we assume 15% charging losses it will take 100kWh to charge a Tesla battery, which will require 100 to 200 square meters to produce in one day. A football field has about 5300 square meters, so we could expect one football field of tightly packed solar panels to charge around 26 to 53 Tesla's per day.