Sunlight: Correlation
Prices it moves with, and why
Sunlight itself is free, so its economic value is set by the cost of the panels, mirrors and collectors that capture it, the land and grid they need, and the power or heat prices it displaces.
No public price Sunlight has no public monthly price series: A free natural flow; no market price, only capture costs.What its price moves with
Solar panels turn most captured sunlight into electricity, so the cost of a solar watt decides how much sunlight is worth harvesting. Falling module prices have made sunny regions such as Rajasthan and Gujarat some of the cheapest places to generate power.
No public price for solar photovoltaics, so the link is explained in words only.Nearly all panels use crystalline silicon wafers cut from polysilicon. Polysilicon booms and gluts, driven by Chinese capacity, move module prices and so the cost of turning sunlight into power.
No public price for polysilicon, so the link is explained in words only.Silver paste forms the contacts on most silicon cells, and solar has become a large part of silver demand. High silver prices push cell makers to thin or replace the paste, which affects module costs.
Not enough overlapping price history to measure.Sunlight arrives only by day, so its value at evening peaks depends on storage. Cheaper lithium iron phosphate batteries let solar output shift to the evening, raising the value of daytime sunlight.
Not enough overlapping price history to measure.Gas plants often set the wholesale power price that solar output earns or displaces. When gas is expensive, every unit of captured sunlight saves more, which is why gas price spikes speed up solar building.
Not enough overlapping price history to measure.How to read these numbers
Correlation of monthly changes (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak.
12-month changes compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs.
Price function is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation.
Lead or lag checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months.
Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link.
Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site.