Tide Collector Liters Time Calculator

Tidal collection time

A coastal tidal collector fills or empties according to how far the tide rises and falls. Along the Brazilian coast that range runs anywhere from 4 m to 15 m, with the highest figures off Maranhão; the Bay of Fundy in Canada, by contrast, hits 16 m, the biggest anywhere on the planet. To work out the filling time you just divide the volume by the average flow rate: t (s) = V (L) ÷ Q (L/s). So a 500 L reservoir fed at 2.5 L/s takes 200 s to fill. The two largest tidal power plants currently running are La Rance in France (240 MW) and Sihwa in South Korea (254 MW), which together prove that harvesting tidal energy at scale is more than a theory.

Applications

Think of the Anchieta/SP feasibility study for a tidal lagoon, hydroelectric plants like La Rance and Sihwa, cisterns sized around salt-water inflow, marine biology stations that sample intertidal volumes, and coastal civil works where you need to estimate dock-gate or dry-dock filling.

FAQ

Why is tidal flow not constant? Over the roughly 6 h between high and low water the velocity traces a sinusoidal curve. It peaks at mid-tide and drops to almost nothing at slack water. The L/s figure here is an average, so the cycle is already smoothed out for you.

How much energy is in a 10 m tide? Take a basin with 10 m of range and 1 km² of surface. It holds roughly 50 GJ per cycle (~14 MWh). Convert that at a realistic efficiency and you could run a few thousand homes for a day.

Why are tidal plants rare? The geography has to line up just right: you need a big range and an estuary you can close off. On top of that the capital cost is steep and the output only comes twice a day. In most regions that makes them a harder sell than wind or solar.