What a megawatt-hour of solar is actually worth

As more solar floods the same midday hours, each one earns less. The capture price is the average price solar actually receives, generation-weighted. Divided by the baseload price, that's the value factor — and it's falling.

A megawatt-hour of German solar earns less than the average price, because solar is worth least exactly when there is most of it. Over the last 12 months, its capture value factor was 0.55 — it earned 55% of the baseload price.

That is a decline driven by solar's own growth: the value factor was 0.78 in 2021 and 0.52 in 2025.

In the rolling window, 22% of all solar generation happened in hours when the price was below zero.

Questions

What is the solar capture rate in Germany?

Over the last 12 months the German solar value factor was 0.55 — a megawatt-hour of solar earned 55% of the baseload price. It has fallen from 0.78 in 2021 to 0.52 in 2025 as solar has grown.

The value factor, falling
Solar Wind Value factor = 1.0
Capture price ÷ baseload, monthly. Generation and price are resampled to one canonical hourly resolution before weighting (Germany switched to quarter-hourly settlement in Oct 2025). Anchors — DE solar capture ~50–60% of baseload, ~16% of solar at negative prices, 573 negative hours — are cited 2025 context, not computed here.
Year by year, the decline
value factor · per calendar year

The monthly line above is the trailing window; this is the long trend. Each point is a full calendar year — solar's value factor has fallen as capacity has piled into the same midday hours. (2022 is the gas-crisis outlier, when every hour was expensive.)

Solar Wind Value factor = 1.0
Annual value factor (capture ÷ baseload) for complete calendar years, from the frozen multi-year history (the current year is still in progress, so it's not shown here). ENTSO-E generation + day-ahead prices.
Capture vs baseload, by zone
€/MWh
Solar capture Wind capture Baseload
Capture = generation-weighted mean price for that fuel; baseload = time-weighted mean. Negative prices are kept, not clipped — they are the point. €/MWh.
The share earning nothing
% of solar generation in negative-price hours.
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