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Tidal energy generation relies on the predictable rise and fall of ocean tides, a rhythm governed by gravitational forces rather than weather patterns. Unlike solar or wind power, whose output fluctuates unpredictably with cloud cover or calm conditions, tidal flow can be forecast years in advance with high precision, giving grid operators a rare degree of certainty when planning electricity supply. This predictability, however, does not eliminate variability altogether, since tidal range differs across the lunar cycle, producing stronger flows during spring tides and weaker flows during neap tides. Construction costs for tidal barrages and underwater turbines remain substantial, and suitable sites with sufficiently strong tidal range are geographically limited to specific coastlines. Despite these constraints, several countries have continued investing in tidal projects, viewing predictability as a valuable complement to less consistent renewable sources already in their energy grids.