Tesla on Tuesday opened the first part of what it said would be a large network of stations that will provide free charges to its electric cars courtesy of the sun.

The company unveiled six Supercharger stations in California, where it is based, and disclosed plans for more to be located "in high traffic corridors" across the continental United States.

Tesla said it will begin installing Supercharger stations in Europe and Asia in the second half of next year. It promised to have more than 100 such stations running in the year 2015.

"Tesla's Supercharger network is a game changer for electric vehicles, providing long distance travel that has a level of convenience equivalent to gasoline cars for all practical purposes," said Tesla chief executive Elon Musk.

"We are giving Model S the ability to drive almost anywhere for free on pure sunlight."

Electricity used by the Supercharger is generated by solar systems designed to procure more energy than will be used by cars, according to the company.

The surplus energy will be directed into local power grids for general use.

"This addresses a commonly held misunderstanding that charging an electric car simply pushes carbon emissions to the power plant," Tesla said in a release.

"By adding even a small solar system at their home, electric car owners can extend this same principle to local city driving too."

Superchargers take about a half-hour to replenish electricity drained by driving three hours at 60 mph (100 kph), according to Tesla.

Tesla in June began deliveries of Model S cars touted as "the world's first premium electric sedan."

Musk, a co-founder of PayPal and SpaceX, created Tesla in 2003 and the company has a factory in the Northern California city of Fremont.

Tesla markets a sports car at more than $100,000 and launched the Model S at a starting price of $49,900.

Without an internal combustion engine or transmission tunnel, Model S has more cargo space than any other sedan and includes a second trunk under the hood.

It accelerates from 0 to 60 miles (100 kilometers) per hour in as little as 4.4 seconds and includes an in-dash touchscreen with Internet capabilities, allowing for streaming radio, Web browsing and navigation.