SolarCity Corporation (SCTY.DL) is the undisputed leader of residential rooftop solar panel kits. With over 262,000 customers to date and plans to reach one million homes by July 4, 2018, this solar company isn't planning to slow down sales any time soon.

But to grow that fast, SolarCity Corporation has to take on new and unprecedented risk. Despite its claims to one-third of all residential solar systems, the company is looking to diversify with home renters, small businesses, energy storage solutions, and even international expansion.

Every year, public companies like SolarCity Corporation have to publish an annual report listing what they believe their biggest risks to be. This list is a must-read for long-term investors, as it lays out every major concern the company should face in the coming years. Here are three risks that, ready or not, SolarCity Corporation will have to overcome on its quest for success.