IN Brief:
- SolarPower Europe reports that 664GW of solar PV was installed globally in 2025, taking the world fleet beyond 3TW in early 2026.
- Growth slowed to 12% in 2025, while global installations are expected to dip temporarily in 2026 before resuming expansion.
- The report places grids, storage, curtailment, and non-fossil flexibility at the centre of solar’s next growth phase.
SolarPower Europe has reported that 664GW of solar PV was installed globally in 2025, taking the world’s solar fleet beyond 3TW in early 2026.
Solar accounted for 77% of global renewable capacity additions in 2025, while solar electricity generation reached 2,778TWh, covering around 9% of global electricity demand. The total global fleet has tripled in four years, confirming solar PV as the dominant source of new renewable capacity worldwide.
Growth is still substantial, but the pace is changing. Annual solar deployment grew by 12% in 2025, a much lower rate than the 30% recorded in 2024 and 86% in 2023. SolarPower Europe expects a temporary contraction in 2026, with global additions falling to 612GW under its medium scenario before expansion resumes from 2027.
China remains the largest market by a wide margin, having installed 382GW in 2025 and accounted for 57% of global additions. India became the second-largest national market with 45.7GW, overtaking the United States. If treated as a single market, the EU-27 would rank second globally, having installed 67.2GW in 2025.
The scale of deployment has changed the technical problem facing solar. Module supply and installation volumes remain important, but system integration is now a central constraint. Grid congestion, curtailment, negative price periods, storage availability, inverter performance, and non-fossil flexibility increasingly determine how much solar generation can be used efficiently.
High solar penetration changes daily power-system operation. Large volumes of daytime output can depress wholesale prices, reduce conventional generation, create local voltage challenges, and increase curtailment where networks cannot absorb or move electricity. Evening ramps then require flexible resources to respond as solar output falls and demand remains high. The more solar is installed, the more important those balancing assets become.
Distribution systems are carrying a growing share of the pressure. Connection queues across European markets already contain large volumes of renewable generation and batteries, with distribution grid constraints delaying clean-energy projects in several countries. The bottleneck is no longer only at the transmission level; local networks must now handle new generation, storage, EV charging, heat pumps, and flexible demand at the same time.
Those conditions raise the specification burden for solar projects. Inverters, transformers, switchgear, protection equipment, communications, monitoring systems, reactive power control, voltage management, and grid-code compliance are no longer secondary design details. They determine whether additional PV capacity can connect, operate, and support the network rather than adding to congestion.
Battery storage is becoming inseparable from solar deployment, although it is not the only flexibility tool required. Short-duration batteries can move midday output into evening demand periods and provide rapid grid services. Longer-duration storage, interconnectors, flexible industrial loads, demand-side response, EV smart charging, and digitalised network operation will also be needed as weather-dependent generation grows.
Inverter capability is becoming a system-resilience issue. Solar and battery inverters now provide active functions around power conversion, fault behaviour, frequency response, reactive power, remote control, monitoring, and, increasingly, grid-forming operation. As inverter-based resources displace synchronous generation, their behaviour during disturbances becomes part of grid stability rather than a product-level feature.
Cybersecurity and remote control also move higher up the technical agenda as inverter fleets expand. Connected power electronics create operational visibility and flexibility, but they also increase dependence on software, communications, firmware updates, data handling, and supplier governance. The procurement of solar and storage hardware is therefore beginning to overlap with critical infrastructure security.
SolarPower Europe’s medium scenario still projects annual installations of around 864GW by 2030, with global capacity reaching 6.6TW. That outlook points to a market that remains structurally strong despite the expected 2026 dip. The harder part of the decade will be matching generation build-out with grid capacity, storage, controls, and flexible demand at comparable speed.
Solar has moved from emerging technology to primary generation source in many markets. The next phase will be judged less by how quickly panels can be installed and more by how effectively electricity systems absorb their output. Grids, batteries, inverters, automation, and flexibility markets are now the infrastructure around solar growth.
