Miguel de Simón Martín
Full Professor in the Electrical Engineering Department at the University of León, in the Electrical Engineering, Systems, and Automation Department, and researcher at the Institute for Research and Innovation in Engineering (I4)
Science magazine's selection of the growth of renewable energy as the milestone of 2025 accurately reflects the magnitude of the change that the global energy system is undergoing. This is not a temporary trend, but a genuine paradigm shift: for the first time, solar and wind energy have grown enough to cover the entire increase in global electricity demand in the first half of the year and have surpassed coal in electricity generation. This progress has been made possible by renewables becoming an economically competitive option, driven largely by China's industrial strategy, which has committed to these technologies both to meet its enormous domestic demand and to export them globally.
The real milestone is not only that renewables are growing, but that they have become the most economical and secure option for meeting most of the world's energy demand.
This positive news, however, calls for cautious reflection. The massive deployment of renewable energy is a necessary but not sufficient condition for addressing the climate challenge. Significant structural challenges remain, such as the adaptation of electricity grids, large-scale energy storage, the electrification of difficult sectors, and the geopolitical tensions associated with China's industrial dominance. Furthermore, China's energy transition has had significant environmental impacts and has not yet led to a complete abandonment of coal, which continues to play a backup role. The underlying message is clear: technology and economics are already aligned, but the ultimate success of the transition will depend on political decisions, adequate energy system planning, and the capacity for long-term sustainable integration.