US electric car maker Tesla has started selling solar roof tiles as the company keeps an 'eye to the future'.
Installation of the glass tiles in US homes begins next month in California and will become international next year, the company says.
The glass tiles, now available online, were unveiled by Tesla last year before the company merged with solar panel maker SolarCity Corp.
They're designed to look like a traditional roof and replicate slate or terracotta tiles.
The solar tiles contain photovoltaic cells that are invisible from the street.
The roof is guaranteed for the life of a home, longer than the 20-year lifespan for a typical, non-solar roof, Tesla CEO Elon Musk says.
He expects initial ramp-up to be slow though.
"It will be very difficult and it will take a long time, and there will be some stumbles along the way. But it's the only sensible vision of the future," Musk said.
Palo Alto, California-based Tesla Inc. is making the solar tiles at its California factory initially before production moves to New York.
Tesla shares have risen from $321.26 to $325.22.
