Musk: SpaceX and Tesla are building 100 gigawatts of solar power capacity annually at top speed, but natural gas will still be needed to supplement and power up the solar power system for the next few years. The bottleneck in natural gas turbine production is the casting of blades and guide vanes. By casting them in-house at SpaceX, we can bring the time to market for natural gas turbines forward by up to 18 months, which will be revolutionary.