There is no IPCC Synthesis Report published in 2026 — the AR7 cycle is not expected to conclude until approximately 2029. The most recent authoritative synthesis is the IPCC Sixth Assessment Report (AR6) Synthesis, published in March 2023. Alongside it, the IEA's Renewables 2025 report (released late 2025) provides the most current independent quantification of solar's deployment trajectory to 2030. Together, these two sources — one setting the scientific demand signal, the other measuring the supply response — give a clear picture of where solar stands and what is still required.
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What IPCC AR6 Says About Solar
The AR6 Synthesis Report confirms that limiting warming to 1.5°C requires rapid, deep emissions cuts across all sectors this decade. On energy supply, the report finds that solar PV and wind are the lowest-cost options for new electricity generation across the majority of the world and must form the backbone of the required transition. AR6 identifies that the mitigation potential of solar is not constrained by resource or technology availability, but by the pace of deployment — which in turn depends on permitting, grid investment, finance access, and policy consistency. The report notes that solar costs have fallen faster than virtually every model projected even five years earlier, meaning the economic case for rapid deployment is now stronger than the AR6 Working Group III models assumed when they were first calibrated.
The Global Capacity Picture: IEA Renewables 2025
The IEA's Renewables 2025 report, covering analysis and forecasts to 2030, provides the most up-to-date deployment data. Key verified figures:
- The world added 605 GW of new solar PV capacity in 2025, according to IEA data published in April 2026 — a record annual addition.
- Global cumulative installed solar PV capacity surpassed 2,260 GW by end-2024, a 29% year-on-year increase, with cumulative capacity by end-2025 broadly consistent with trajectory toward approximately 2.8 TW.
- The IEA forecasts approximately 540 GW of average annual solar additions through to 2035, representing a plateau at historically unprecedented deployment levels.
- Solar PV accounts for nearly 80% of all new renewable electricity capacity additions between 2025 and 2030.
The Gap Between Deployment and the 1.5°C Pathway
Despite record additions, the IEA's Net Zero Emissions by 2050 scenario requires solar deployment to continue accelerating, not plateau. The gap between projected deployment and the NZE pathway is narrowing but has not closed. The principal bottlenecks are grid infrastructure (particularly in Europe and North America, where connection queues constrain new projects), permitting timelines, and the pace at which existing fossil generation is retired to make room for variable renewables on the grid. The AR6 finding that policy consistency matters more than technology cost is increasingly borne out in markets where grid and planning constraints are the binding constraints rather than module prices.
What This Means for EU Solar Specifically
The EU reached approximately 406 GW of cumulative installed solar PV capacity (DC) by end-2025, according to SolarPower Europe's annual market report — meeting its 2025 strategy milestone. The EU Solar Strategy targets approximately 750 GW DC by 2030, consistent with the binding 42.5% renewables share under RED III. Annual EU additions ran at 65.1 GW in 2025, a slight decrease from 2024, and the market contraction is flagged by SolarPower Europe as a risk to the 2030 target. Residential solar's share of EU additions fell to approximately 14% in 2025, down from 28% in 2023, highlighting a shift toward utility-scale deployment.
The Residential Contribution
AR6 acknowledges that distributed solar — including rooftop residential — plays an important role in accelerating deployment because it avoids many of the grid-connection and land-use challenges facing utility projects. IEA data shows distributed solar (residential, commercial, industrial, and off-grid) accounting for approximately 42% of global PV expansion in the Renewables 2025 forecast period. For individual homeowners, the scientific message is that the action they take is consistent with what the climate trajectory requires; the economics, made favourable by falling module costs and rising retail electricity prices, align with the science in a way they did not a decade ago.
Key Takeaways
- No IPCC report was published in 2026; the AR6 Synthesis (March 2023) remains the current scientific benchmark for climate and energy findings.
- The world added 605 GW of solar in 2025 — a verified record, per IEA data published April 2026.
- Global cumulative solar PV exceeded 2,260 GW by end-2024, on a trajectory toward approximately 2.8 TW by end-2025.
- The EU reached ~406 GW DC cumulative by end-2025, meeting its 2025 strategy milestone; the 750 GW 2030 target now requires sustained recovery in annual additions.
- AR6 identifies deployment pace — not technology cost or resource availability — as the binding constraint on solar's climate contribution.
The science is clear, the economics are favourable, and the deployment data confirms the trajectory — even if the pace still needs to accelerate. Explore Comparisun's tools to see how a residential system fits into this picture for your location and budget.