Installations of photovoltaics in 2016 saw a near unprecedented year-on-year growth of 50%, from 50 GW in 2015 to 75 GW in 2016 – growth not seen since 2011. It is clear that photovoltaics have now established themselves as a mature choice for future energy needs. However, with shifting policy landscapes, a cooling Chinese market, and emerging markets just beginning to install solar it is unclear if how the market will evolve over the next five years. We forecast demand out to 2021, examining a baseline trajectory of current trends and find a slower but steady growth. But given the tumultuous nature of the market, we also examine two scenarios: one where policy support declines in the U.S. but the key markets in the Middle East grow; two in which storage deployment is accelerated in countries where curtailment and grid reliability are issues. These present two very different outlooks for the market, with a 2021 annual installation spread of 46 GW.