One of the most prominent criticisms of SolarCity prior to being acquired by Tesla (NASDAQ: TSLA) was that the solar installer had a cash flow problem.
This situation was created by the fact that SolarCity rose to become the No. 1 installer largely through its leasing model, which offered customers solar power at little to no upfront cost. But that required the company to invest its own money upfront into systems that it would subsequently monetize through lease payments and power purchase agreements (PPAs) over the course of decades.