As the scale of solar cell and module (panel) factories continues to grow, the price of solar declines with it. Like computers and phones, solar is a technology that benefits from the learning curve–the more you make of something, the cheaper it gets. In the Freeing Energy Project, we refer to this as economies of volume, to contrast it with traditional economies of scale that have been the primary mechanism to lower costs for every other type of electricity generation.
Over just ten years, the number of factories making solar PV has skyrocketed. This increase in manufacturing capacity is one of the biggest reasons the cost of solar has fallen almost ten-times over the same period.
The spreadsheet below contains the source data for this graph.