The rising sun: a new day dawns for energy with renewables

2025 will be remembered as the year when the sun eclipsed nuclear power. For the first time in history, solar energy generated more electricity than nuclear across the globe. This has been confirmed by the think tank Ember, which describes a “tipping point” in the global energy system: renewables, driven by solar and wind power, are no longer a promise for the future but the primary source of new electricity generation.

According to the Renewables 2025 report from the International Energy Agency (IEA), global renewable capacity will double by 2030 with a growth of 4,600 gigawatts, or the equivalent of the total installed power of China, the European Union, and Japan. 80% of this growth will come from solar, which already covered 83% of the increase in global electricity demand in 2025, a figure which would have been unimaginable just ten years ago. The cost of panels has plummeted by 90% over fifteen years, making solar energy the cheapest in human history. This revolution stems not only from national policies, but also from companies investing in direct supply contracts, energy communities, and citizens installing systems on their rooftops and in rural areas.

China: from solar factory to clean energy powerhouse. When it comes to solar energy, no country has made greater strides than China. From coal giant to photovoltaic colossus, Beijing is now the world’s largest producer and user of solar energy. With over 1,400 GW of installed capacity between solar and wind power, it has already exceeded its 2030 target. The turning point was aided by a change in the model: abandoning guaranteed fixed tariffs in favour of competitive auctions and contracts for difference, which triggered a rush in installations in the first half of 2025. In the first five months of the year alone, China added 200 GW of new solar capacity, a record figure that turns the country’s energy narrative on its head and shows that even the largest coal-based economy can become a global leader in clean energy.

The United States: ambition meets regulatory delays. Looking across the ocean, on the other hand, the US is rife with contradictions. The IEA has slashed its estimate for the growth of renewables in the country by 50%, a cut linked to less favourable policies such as the early phase-out of federal tax credits, import restrictions, and judicial suspensions of major offshore projects. The case of the mega offshore wind farm in the Atlantic, which has ground to a halt for environmental and legal reasons, has become emblematic. Despite its technological leadership, the US faces lengthy authorisation processes and regulatory uncertainty. However, the demand for clean energy remains very high, with American companies increasingly signing private supply contracts, accounting for 30% of new global installations alone.

Africa: the desert sun rises. While photovoltaics are booming in Asia and struggling somewhat in the West, the future is bright in Africa. Though still marginal in terms of global production, the continent is today a cradle for new energy. The Sahara desert, Morocco, and Egypt are home to emerging solar power plants that can light up entire regions. In Kenya, Nigeria, and South Africa, mini solar plants are spreading far and wide, bringing electricity to places it never reached before. According to the IEA, African solar capacity will grow by 30% over the next five years, driven by international investments and energy cooperation. With some of the highest levels of solar irradiance on the planet and new transmission grids under construction, Africa could become a future exporter of green energy to Europe and the Middle East.

Europe: the home straight. Europe, a pioneer in climate policies, is racing to achieve its REPowerEU target: 1,236 GW of renewables by 2030, more than half of it solar. Germany, Spain, and Italy are leading the growth thanks to long-term contracts and the spread of residential and industrial plants, but the acceleration of solar power is creating new tensions. As written in Bloomberg, the surge in solar power production is putting “unprecedented strain” on European transmission grids. In some nations, production can exceed demand during summer afternoons, forcing operators to shut down part of their plants or export the excess energy. Infrastructure designed for a centralised system struggles to withstand the impact of such widely scattered generation. Long connection times, rising grid costs, congestion, and fluctuations in frequency have become the new frontline of the transition. This is a systemic phenomenon, as the renewables revolution risks becoming stalled at a technological bottleneck without an adequate grid and the development of storage systems.

The role of grids: flexibility, intelligence, interconnection. According to the IEA, 45% of the world's electricity will be generated from renewable sources by 2030, and 30% from variable solar and wind. But the challenge is no longer simply to produce clean energy: it is to transport and manage it, which is where grids come into play. The exponential growth of solar requires stronger, more digital and interconnected transmission systems, where high-capacity transport lines, direct current connections, storage systems, and smart flow management form the core of the new energy infrastructure.

In Italy, Terna is a key player in this transformation. With a grid of over 75,200 kilometres of lines and a ten-year investment plan exceeding 23 billion euros, the company is building the backbones that will allow solar and wind energy produced in the South to be integrated with consumption centres in the North. In this sense, new HVDC lines such as the Tyrrhenian Link, the Adriatic Link, and the Hypergrid project represent the highways of the transition.