Solcast’s mid-year review of global solar resource put H1 2026 irradiance across most of Europe and the United States at 5 to 10 percent above the 2007 to 2025 baseline. France came in 13 percent above, Germany 11 percent, Finland 16 percent, and Austria’s May hit 25 percent above normal. The upside was not universal. Canada, Mexico, South Africa, North Africa, and parts of western Russia and Central Asia sat 5 to 10 percent below baseline. Australia’s central and eastern regions saw 15 to 30 percent deficits in February. Hong Kong’s January print was more than 25 percent above.
Solcast attributes the redistribution to early-year atmospheric blocking and polar vortex disruption transitioning to a developing El Nino pattern from April, layered on top of the usual regional noise from cyclones, dust, smoke, and rainfall variability.
Why this matters for developers and analysts
Solar generation economics are a linear function of irradiance at first order. A 5 to 10 percent surplus against the P50 assumption baked into a project’s pro forma flows through as roughly proportional upside on revenue in a merchant book and on availability payment coverage in PPAs. Utility-scale operators in the affected European countries and across most of the US will book that upside in Q2 and Q3 disclosures, even if they do not attribute the swing to the underlying atmospheric pattern.
The reverse holds for Canadian and Mexican fleets. Operators in those regions have been running against baseline through H1 and should be underwriting Q3 guidance with less headline generation than the same portfolios delivered in 2024 or 2025.
What to track
The signal to watch is whether developers and independent power producers reference the above-baseline pattern in Q2 earnings. Most will not; the industry norm is to bench-mark against long-term normals and treat single-year variance as noise. The read-through for lithium and storage arrives one step downstream. Grids running above expected solar output shift storage arbitrage windows and firm up the case for four-hour and longer duration batteries to absorb midday over-generation, especially in ERCOT and CAISO where duck curve dynamics compound.
The second-half read depends on whether the El Nino pattern that drove the H1 swing consolidates or fades. Solcast flagged both as live possibilities.