Michael Graham Richard for TreeHugger:  Soon after SolarCity acquired solar panel maker Silevo in the summer of 2014, it announced the construction of a 1.2-million-square-foot 'Solar Gigafactory' in Buffalo, New York. The move had two main goals: 1) For the solar installer to get its own secure supply of high-efficiency solar panels (Silevo panels are currently 21% efficient, but the company claims that they can get to 24%) and 2) drive down the cost of the panels and of installing them.
If the panels are higher efficiency, you need fewer of them per roof for a given capacity, lowering installation costs, and if you make them in very large quantities in a 'Gigafactory', you can further reduce costs through economies of scale.
The Buffalo solar gigafactory, which can be seen in the photo at the top of this article, aims to start producing solar cells in 2016, with a ramping up to 1 GW of annual capacity by 2017. If all goes well, the facility could eventually be expanded to 5 GW/year at some point. The solar cells produced there have a target price of around $0.50/watt, which would make them very competitive with other power sources.  Cont'd...