OTEC and salinity power: Correlation
Prices it moves with, and why
OTEC and salinity power are at pilot scale, so costs reflect large heat exchangers or membranes, deep cold-water pipes and moorings. Value comes from steady output and fresh water on tropical islands that otherwise burn diesel.
No public price OTEC and salinity power has no public monthly price series: Pilot plants only; no commercial price.What its price moves with
Heat exchangers must resist seawater, so many OTEC designs use titanium plates. Titanium is costly, and exchangers are a large part of total cost. Aluminium exchangers are tested as a cheaper option.
Not enough overlapping price history to measure.Closed-cycle OTEC plants boil ammonia with warm surface water and condense it with cold deep water. It is a small cost but central to the cycle. Ammonia boils at low temperature.
Not enough overlapping price history to measure.The cold-water pipe reaching hundreds of metres deep is often made of HDPE or fibreglass. Pipe cost and durability are key to OTEC economics. Pipe failures have ended past pilot projects.
Not enough overlapping price history to measure.Open-cycle OTEC produces fresh water as a by-product, which can be worth as much as the power on dry islands. Salinity power, by contrast, needs fresh river water as input.
Not enough overlapping price history to measure.Island grids where OTEC suits often burn diesel or fuel oil. High oil prices make OTEC more competitive there. Shipping fuel to remote islands adds to its cost, so steady local power is worth more.
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.