Wave Power
Estimate the power flux of an ocean wave per meter of wave front, P ≈ 0.5 × H² × T, from the wave height H (m) and the period T (s), in deep water (seawater). The result, in kW/m, is the power available per meter of wave front width — a key indicator of wave energy potential for converters (WECs). Coasts exposed to ocean swells (European Atlantic, Pacific) reach 30-70 kW/m, a significant renewable resource. The power grows with the square of the height and linearly with the period. Enter the wave height and period.
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Wave power
While wave energy is how much a wave holds, power is how much it delivers per second — the energy flux crossing each metre of an imaginary line parallel to the wave front. For deep-water waves, a good practical approximation is P ≈ 0.5 × H² × T, with wave height H (m), period T (s) and the result in kW per metre of wave front. Power scales with the square of the height (as energy does) and with the period as well (longer-period waves carry their energy faster, thanks to a higher group velocity). This is the number that defines the wave energy resource of a region. Coastlines exposed to long ocean fetches and to swells from distant storms show impressive figures: the Atlantic coast of Europe (Portugal, Ireland, Scotland), the North American Pacific and southern Australia reach 30-70 kW/m as an annual average — meaning that a few kilometres of shoreline concentrate gigawatts of power. Wave energy is an attractive renewable source: much denser than solar or wind (water is ~800× denser than air), more predictable (swell can be forecast days ahead) and available day and night. The challenge is technological: wave energy converters (WECs) must survive a hostile marine environment and extreme storms while efficiently capturing energy that arrives as slow, high-force oscillating motion — a problem still unsolved at competitive commercial scale, though many prototypes exist. Enter the wave height and the wave period.
Related Tools
Wave Energy
Calculate the energy density of an ocean wave, E = (1 ÷ 8)·ρ·g·H², from the water density ρ (kg/m³, ~1025 for seawater), gravity g and the wave height H (m). The result, in J/m² (energy per surface area), is the sum of the wave's kinetic and potential energy — proportional to the square of the height, so large waves carry far more energy. It is the basis for calculating wave energy generation potential and the impact on coastal structures and beach erosion. Enter the water density and the wave height.
Wave Group Velocity
Calculate the group velocity of an ocean wave in deep water, c_g = g·T ÷ (4π), from the period T (s). The result, in m/s, is the speed at which the wave energy (and the 'envelope' of a wave group) propagates — exactly half the celerity (phase velocity) in deep water. This difference explains a curious phenomenon: within a wave group, individual crests appear at the rear, advance through the group (faster than it) and disappear at the front. The group velocity is what matters for energy transport and predicting swell arrival at the coast. Enter the wave period.
Deep Water Wave Celerity
Calculate the celerity (phase velocity) of an ocean wave in deep water, c = g·T ÷ (2π), from the period T (s) and gravity g. The result, in m/s, is the speed at which the wave crest propagates. In deep water, longer-period waves travel faster — a phenomenon called dispersion, which makes long-period swell reach the coast before the short waves generated by the same storm. The celerity is half the group velocity (at which energy travels) in deep water. It is a base concept of wave hydrodynamics. Enter the wave period.
Wave Period
Calculate the period of a wave, T = 1 ÷ f, from the frequency f (Hz). The result, in seconds, is the time between two successive crests passing a fixed point — one of the most important properties of an ocean wave. The period determines the wavelength and celerity (in deep water), the depth at which the wave interacts with the bottom, and classifies the sea state: local wind waves have short periods (3-8 s), while swell from distant storms has long periods (10-20 s), travels faster and penetrates deeper. The period is measured by buoys and used in wave forecasting. Enter the wave frequency.
Ocean Wavelength
Calculate the wavelength of an ocean wave in deep water, L = g·T² ÷ (2π), from the wave period T (s) and gravity g (9.81 m/s²). The result, in meters, is the distance between two successive crests — in deep water, it depends only on the period. Long-period waves (swell from distant storms) have much larger wavelengths than local wind waves. The wavelength sets the depth at which the wave 'feels' the bottom (about L/2), starts to refract and shoal until it breaks. It is a fundamental parameter of linear wave theory and coastal engineering. Enter the wave period.
Three-Phase Voltage Unbalance (NEMA)
Measures the unbalance of the three line voltages of a three-phase system by the NEMA MG-1 criterion, the same one used by motor derating curves. The calculation takes the average of the three line voltages, finds the largest absolute deviation between any voltage and that average, and divides this deviation by the average, as a percentage. The number has a direct consequence: NEMA forbids operating induction motors above 5%, recommends derating from 1% on (at 2% the derating factor is already about 0.95) and warns that 1% of voltage unbalance can become 6 to 10% of current unbalance, with extra rotor heating. The NEMA definition was adopted (largest deviation divided by the average, also called LVUR) rather than the IEC and IEEE unbalance factor, which is the ratio between negative and positive sequence components and requires full phasors, not just magnitudes. Enter the three measured line voltages.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.