Tesla will soon begin selling solar roof tiles. Tesla CEO Elon Musk tweeted early recently that ordering would begin later in the day. Musk said the tiles will be sold worldwide. They’ll go to US customers first this year and to other countries next year. He gave no other details. Palo Alto, California-based Tesla, which makes electric cars, announced last fall that it would produce the tiles with solar power company SolarCity Corp. Tesla and SolarCity completed a merger in November. The glass tiles are designed to look like a traditional roof, with options that replicate slate or terracotta tiles. They contain photovoltaic cells that Tesla says are invisible from the street. The energy from the tiles can power a home when combined with Tesla’s Powerwall energy storage unit.