Tidal Energy Output Calculator

Work out tidal energy output instantly with clear inputs, formula shown and shareable results.

About Tidal Energy Output Calculator

The potential energy in a tidal basin is 0.5 x seawater density x g x area x range squared, because the average head over the emptying cycle is half the range. Energy scales with the square of tidal range, which is why only a handful of sites worldwide with ranges above 5 metres are viable.

Formulas

Tidal basin energy

E per cycle (J) = 0.5 x rho x g x A x R^2

Annual output

Annual energy = E per cycle x cycles per day x efficiency x 365

Worked example

With the default values below, Tidal Energy Output Calculator returns Annual Energy Output of 256,911.6. Change any input above and every figure here is recalculated in your browser.

Inputs used

Tidal Basin Areaminimum 0 km2: 20 km2
Mean Tidal Rangeminimum 0 m: 6 m
Tidal Cycles Per Dayaccepts 0.1–4: 2
Conversion Efficiencyaccepts 1–100 %: 35 %

Results

Annual Energy Output: 256,911.6
Daily Energy Output: 703.868
Average Power: 29.3278
Theoretical Energy Per Cycle: 1,005.525

Step by step

1Values used
2Tidal basin energy
3Annual output
4Annual Energy Output= 256,911.6
5Daily Energy Output= 703.868
6Average Power= 29.3278
7Theoretical Energy Per Cycle= 1,005.525

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Tidal barrage and lagoon schemes have major effects on estuarine ecology, sediment transport and navigation, and require extensive environmental assessment and consent.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Tidal barrage and lagoon schemes have major effects on estuarine ecology, sediment transport and navigation, and require extensive environmental assessment and consent.

Frequently Asked Questions

Why is efficiency only 30-40%?

Single-basin ebb generation can only use part of the head, the turbines operate over a varying head far from their design point, and generation must stop while the basin refills. Two-way and multi-basin schemes improve on this at higher cost.

Is tidal energy predictable?

Yes, decades ahead, which is its main advantage over wind and solar. It is not, however, dispatchable — output follows the tide, which shifts about 50 minutes each day relative to demand.