Is a solar future inevitable?

Abstract

Decarboni sation plans across the globe require zerocarbon energy sources to be widely deployed by 2050 or 2060. Solar energy is the most widely available energy resource on Earth, and its economic attractiveness is improving fast in a cycle of increasing investmen ts. Here we use datadriven conditional technology and economic forecasting modelling to determine which zero carbon power sources could become dominant worldwide. We find that, due to technological trajectories set in motion by past policy, a global solar tipping point may have passed where solar energy gradually comes to dominate global electricity markets, even without additional climate policies. Uncertainties arise, however, over grid stability in a renewables dominated power system, the availability o f sufficient finance in the Global South, the capacity of supply chains and political resistance from regions that lose employment. Policies resolving these barriers may be more effective than price instruments to accelerate the transition to clean energy. 3