Solar output arrives at the same hours everywhere on a grid, so every panel added lowers the price every other panel earns. The capture rate, what a technology's output actually earned as a share of the year's average power price, measures that cannibalisation directly. Below: every European grid in Kortex with a decade of hourly generation and day-ahead prices, joined hour by hour.
Loading a decade of hourly joins…
The decline, year by year
capture rate by calendar year; 100% means the fuel earned the market average; each line is one bidding zone. Only coverage-qualified grid-years are drawn (≥85% of the year's hours joined).
It isn't the calendar; it's the share
the same grid-years plotted against the fuel's share of the grid's generation. Country lines collapse onto one curve: capture decline tracks penetration, wherever and whenever it happens. Point colour = year (dark 2015 → bright 2025).
First full year vs latest, per grid
coverage-qualified years only · Δ columns compare the grid's first qualified year to its latest · levels are in each zone's native market currency; the rate is unit-free
Method & receipt. Capture price = generation-weighted average day-ahead price per fuel, grid and calendar year; what the market paid that output, never its cost. Base price = the same year's time-weighted average; capture rate = the ratio, a unit-free percentage, so zones settling in EUR, GBP or RON compare honestly (levels are never compared across currencies; each zone's dominant price series per year is used). Hourly join of ENTSO-E actual generation × day-ahead prices; sub-hourly series are averaged to the hour before joining; negative price hours are kept; they are the story. Penetration = the fuel's share of total generation energy, same year and zone; the ENTSO-E "Solar" category includes solar thermal alongside PV, so shares can sit slightly above the PV-only figures national operators publish (Spain 2025: 20.3% here vs 19.1% PV-only peninsular from Red Eléctrica; the gap is CSP plus denominator scope). Coverage fails closed: grid-years with under 85% of hours joined, under 10 GWh of the fuel's output, or a non-positive base price are flagged and never drawn or ranked; this excludes partial edge years and Germany, whose generation history in Kortex currently starts in 2024. No subsidy, PPA, curtailment or balancing revenue is modelled: this is energy-market revenue only. GET /v2/spatial/capture-decline · sources.