Historically, tidal power in the US has only been provided by dams. However, a recent project by the Ocean Renewable Power Company (ORPC) has just confirmed energy delivery to the US grid from their newly developed TidGen turbines. Officially installed on September 13th in the Cobscook Bay off the coast of Maine, the TidGen provides supporting evidence for investing towards harnessing tidal power as a source of renewable energy. Other recent developments in this technology, coupled with an encouraging amount of potential areas in which to implement, lay a strong foundation for future renewable projects to build on.

TidGen An animation of the TideGen underwater generation device.

ORPC’s 180kw TidGen, hovering 15-30 meters underwater, generates enough energy to support 25-30 homes annually at its peak output. Though this sounds like small change, it’s only the first TidGen developed and installed as a result of this $18 million dollar energy project. Cobscook Bay is a small segment of the much larger Bay of Fundy, which sees a stunning 100 billion tons of water flow in and out of the bay each year. With so much potential in the area, ORPC plans to monitor the success of the first TidGen and implement a system capable of producing 5 Mw within 3 years (powering approximately 1,200 houses).

Related Innovations

One similar concept to ORPC’s most recent developments stems from researching waves. The basic concept behind tidal power is the constant force exerted by gravity, dictating a relationship between the Earth and the moon. A similarly consistent side-effect of this interaction comes in the form of ocean waves. The consistency of motion in oceanic areas is an ideal leverage point for renewable energy development, and various strategies have been proposed in pursuit of capturing this.

One such innovation is wave power, which has seen global potential estimates as high a 2,100 terrawatt-hours per year. A reasonable way to cash in on this free resource has been postulated in Portland by Ocean Power Technologies (OPT) via a buoy system. More specifically, the pilot project utilizing OPT’s PB150 PowerBuoy looks to approach this via a piston system. By attaching these buoys in areas with high wave volatility, the variance water level could capture up to 150kw per buoy. Considering how small they are, it would require a reasonably small amount of area to capture a large amount of energy. Though less consistent than tides and dams, this alternative holds the value of implementation across an enormously large area. Good innovating, to say the least.

The first TideGen device before installation in Cobscook Bay, Maine.

Tidal Potential

The potential tidal power worldwide is a difficult task to estimate. Some estimates sit around the 90 gigawatt mark, implying a substantial opportunity to be capture if the technology continues to evolve towards high efficiency and reasonably priced equipment. A group at Georgia Tech University has gone a step further in detailing a global map that outlines the ideal tidal energy locations worldwide, providing a powerful tool in strategizing the implementation of such technologies. These studies demonstrated that the US geographic region alone held the potential to power 15% of current energy requirements domestically. As tidal power is both predictable and consistent, particularly when compared to other renewable sources, this is a distinct energy opportunity if the R&D continues to bear fruit.

Bottom Line

With the development of various technologies designed specifically to capture the constant ebbs and flows of the sea, it would not be surprising for the renewable technologies to shift more and more in this direction. Solar power, shale gas, cleaner fossil fuels, and wind power all stand to see improvements, but tidal power is still a more undefined frontier. ORPC broke great deal of ground with TidGen, and the PowerBuoy concept is also quite promising. Combine the developing innovations with the natural potential in the consistent movements of the sea and it is a reasonable conclusion that tidal power might hold some sway in the renewable energy future.