Offshore Wind Foundation Calculator

Te is a spectral-average quantity that would normally require the full wave energy spectrum to compute exactly, but for a typical JONSWAP spectrum with a peakedness factor around 3.3 — representative of most wind-generated seas — the ratio Te/Tp consistently comes out close to 0.9. This calculator uses that standard shortcut so you only need to supply the peak period Tp, which is far more commonly available from buoy data or hindcast records than Te itself.

The deep-water wave power formula assumes waves haven't started interacting with the seabed, which only holds when depth exceeds about half the wavelength. Once the site's depth-to-wavelength ratio drops below 0.5, the calculator computes a group-velocity ratio from the linear dispersion relation and multiplies the deep-water power flux by it, because shoaling in shallower water changes how much of that power actually propagates to the device — ignoring this would overstate the resource at nearshore sites.

A true capacity factor would compare actual annual energy output to what the device would produce running at its rated power continuously, which requires integrating power output across the full joint distribution of wave heights and periods the site experiences over a year. This calculator only evaluates one representative sea state (a single Hs and Tp), so it substitutes device availability as a simplified stand-in rather than claiming a resource-weighted capacity factor it can't actually compute from a single input pair.

It's meant as a first-pass screening tool for comparing candidate sites or converter capture widths and efficiencies, not a final design calculation. A bankable annual energy estimate needs a full spectral analysis across the site's actual scatter diagram of sea states per IEC TS 62600-100, since real wave climates rarely stay at one Hs and Tp long enough for a single-point estimate to represent annual production accurately.