A large-scale taxi operation like this one would be an ideal candidate for a private supercharger. Yes, you read that correctly. Tesla can and will supply supercharger hardware to individuals and businesses that require fast charging on a daily basis. Base-level superchargers that can charge two cars at a time have already been sold for private use in the U.S. Obviously, in this instance the owner of the installation pays for the energy used, and it's unlikely that you would be able to install one in a residential neighborhood due to power requirements. For roughy the cost of 3 to 4 Model S taxis, a dedicated 4-bay supercharger could be purchased.