As more communities turn to solar energy to reduce emissions and power daily life, a growing challenge is emerging solar power droughts multi-day periods when demand for solar electricity outpaces supply are becoming more frequent and severe, particularly in tropical and developing regions.
A new global study by Lei et al. analyzed solar power supply and demand patterns between 1984 and 2014, identifying troubling trends. During this 30-year span areas such as the western U.S., eastern Brazil, Southeast Asia, and large parts of Africa faced at least five solar power droughts per year with the frequency of these shortages increasing by nearly 0.76 events per decade. Climate driven changes in weather and energy needs were responsible for nearly one-third of all observed droughts during this period.
Solar droughts occur when cloud cover, storms, or air pollution reduce solar generation just as extreme heat drives up demand for cooling and cooking. This mismatch can leave millions without reliable power during times of urgent need, especially in regions lacking robust energy infrastructure.
The researchers also looked ahead using climate models. Under a medium emissions scenario (SSP2-4.5) often used in UN climate projections solar droughts are expected to become seven times more frequent and 30% more intense by the 2090s. In lower-emission scenarios, the worst impacts would peak by the 2060s and then decline, highlighting the crucial role of emissions reductions.
The authors argue that addressing these power droughts requires more than just building solar farms. Investments in energy storage, grid resilience diversified renewables, and emissions mitigation are essential to avoid leaving vulnerable populations in the dark.
Our findings underscore how essential it is to limit emissions not just to cool the planet but to secure a reliable, clean energy future,” the researchers conclude.