Earth's heat: Correlation
Prices it moves with, and why
Earth's heat is free and constant, but reaching useful temperatures needs drilling. Its value depends on drilling costs, the local geology, and the power and heat prices it competes with; drilling is shared with the oil and gas industry.
No public price Earth's heat has no public monthly price series: A free natural flow; no market price, only capture costs.What its price moves with
Geothermal power plants turn hot underground fluids into electricity where hot rocks lie near the surface, such as Iceland, Kenya and Indonesia. Their output is steady, unlike wind and sun.
Not enough overlapping price history to measure.Direct use and ground-source heat pumps use shallower, cooler heat for buildings, greenhouses and baths. This is the most widely spread way to use earth's heat. Its value is the gas or electricity it saves.
Not enough overlapping price history to measure.Enhanced and closed-loop systems drill deep into hot dry rock to create reservoirs, aiming to use earth's heat almost anywhere. Their cost depends on drilling speed and depth. Faster oilfield drilling methods help cut this cost.
Not enough overlapping price history to measure.Geothermal wells use the same rigs, crews and casing as oil and gas wells. When oil drilling booms, rig rates rise and geothermal projects cost more. Oil and gas skills also transfer directly to geothermal.
Not enough overlapping price history to measure.Well casing and plant pipework use large amounts of steel that must cope with heat and corrosive brines. Steel prices feed into drilling and plant costs. Deep, hot wells need special grades that cost more.
Not enough overlapping price history to measure.Gas competes with geothermal for both power and heat. High gas prices improve the case for geothermal, while cheap gas has often pushed it aside. Gas price spikes have revived interest in geothermal heating.
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.