Tesla CEO Elon Musk says construction of the electric car maker’s Nevada gigafactory is being ramped up, because of the demand for the company’s new moderately priced Model 3. The company announced plans to hire ten thousand workers, original plans called for 65 hundred. Musk says that could happen over the next three or four years, as Tesla expects to sell 500,000 electric vehicles in 2018, two years ahead of schedule. The $5 billion gigafactory is now expected to begin producing batteries late this year, ahead of schedule. He calls the facility the most exciting factory in the world.