At the beginning of the year, Wood Mackenzie asked whether solar could keep its momentum in 2025 while facing policy uncertainty, protectionist measures and interconnection bottlenecks.

The question was relevant because solar had already gone through a period of rapid expansion. After years of strong growth, 2025 was expected to become a year of rationalisation: less about volume alone, and more about how the market adapts to pressure.

As the year closes, the picture is clearer.

Global solar installations are heading for another record year. Around 380 GW were added in the first half of 2025 alone, a 64% increase compared with the same period in 2024, driven largely by China.

At the same time, the European market is showing signs of slowdown. New EU solar installations are projected to dip slightly to around 64.2 GW in 2025, marking the first decline in a decade, even as the bloc reaches its 400 GW target.

This contrast matters.

Globally, solar continues to scale. Regionally, however, growth is becoming more uneven. Policy uncertainty, grid constraints, trade rules and interconnection delays are starting to influence how quickly new capacity can move from ambition to implementation.

Oversupply has also forced manufacturers to rethink their strategies. Global PV manufacturing capacity has moved well beyond demand, pushing major players to curb production and agree minimum pricing. This confirms that 2025 did become a year of rationalisation, not only expansion.

Medium-term forecasts have also been revised. The IEA now expects solar additions to average around 540 GW per year to 2035, a strong outlook, but one that also recognises the friction facing the sector.

For us, the lesson from 2025 is clear: headline records still matter, but the real story sits in how new capacity withstands policy swings, trade measures and grid limitations.

Solar is no longer measured only by how fast it grows. It is also measured by how well it integrates into energy systems, how resilient its supply chain becomes and how effectively it works alongside storage and flexibility solutions.

That is the lens we carry into 2026.

Solar will remain central to the energy transition, but its next phase will depend on more than deployment numbers. It will depend on system readiness, grid capacity, storage, regulation and the ability to turn growth into reliable clean energy infrastructure.