URS Corporation has been selected by the San Francisco Public Utilities Commission (SFPUC) to conduct a study of the feasibility of harnessing tidal flows in San Francisco Bay through the Golden Gate as a source of clean, sustainable energy.

Tidal flows in and out of San Francisco Bay consistently generate high velocity currents in the Golden Gate narrows. High velocity produces a concentration of tidal energy, some of which can theoretically be captured by submerged in-stream tidal energy devices. These devices would be submerged at depth in the 300-foot-deep passage to avoid visual impacts near the Golden Gate Bridge. Most in-stream devices look like the underwater equivalent of wind farm turbines.

The key issues to be addressed in the study are how much energy is available; how much can be extracted without adversely affecting the tidal exchange; what the impact might be on protected fish and mammal species; and is the concept economically viable.

The scope of work of the feasibility study is divided into three tasks:

- Perform a technology screening assessment by development of a feasibility ranking matrix for existing and promising technologies;

- Conduct computer modeling of the Bay/Golden Gate system to assess total extractable energy and the percent of energy that can be extracted without adverse impacts on the Bay’s tidal prism and ecosystem; and

- Identify and hold meetings with stakeholders.

The study will produce recommendations on which technology should be carried forward in a pilot study near the Golden Gate.

The feasibility project is part of an overall plan by Mayor Gavin Newsom to position San Francisco as a global hub for the creation and use of clean energy.