The company, backed by Tesla Motors' founder Elon Musk, will pay $200 million in shares and an additional $150 million in shares upon the achievement of certain milestones, SolarCity said in a regulatory filing.
"Given that there is excess supplier capacity today, this may seem counter-intuitive ..." SolarCity Chairman Musk and co-founders Peter Rive and Lyndon Rive wrote in a blog.
"Without decisive action to lay the groundwork today, the massive volume of affordable, high efficiency panels needed for unsubsidized solar power to outcompete fossil fuel grid power simply will not be there when it is needed."
SolarCity has grown rapidly because it allows homeowners to pay a monthly fee to lease solar panels instead of making a large upfront payment, but the company's costs have also escalated with its dramatic growth.
A glut of panels, mostly produced in China, has depressed prices, but analysts have warned that SolarCity may be affected by the United States' recently imposed import duties on solar panels and other related products from China.