Alternative Energy, Energy

Energy in the current?

Over the past few years, there has been a major push towards transitioning to a renewable energy source that can keep this country going. The main renewable ideas that have been highly publicized include solar, wind and minimally biofuels, but there are still multiple options that are still available.

One of these new innovative and renewable energy resources being investigated is within the currents of the ocean. We already know that the globe is covered with 70% of water, and there has already been research into using water for mills and other hydroelectricity technologies, but this is vastly different. This technique is Hydrokinetic Energy, and is just as it sounds; it harnesses the kinetic energy from the water. Deep in the ocean, as well as within other water sources, there is a natural flow, or current, moving the water. That current is constantly flowing, and although it is affected by many different variables, the currents are relatively consistent and flow in one direction. This new kind of energy source being studied could be very renewable and reliable, as we have water sources all around the globe that can reach almost everyone. It was estimated by the BOEM (Bureau of Ocean Energy Management) that harnessing only 1/1000th of the energy available within the currents would supply 35% of Florida’s electrical needs.


Major Ocean Surface Currents (Source: NOAA)

One of the first techniques that has been researched to harness this energy is using a turbine system; placing these turbines deep in the ocean and letting the current do the work. These turbines require 5 knots of energy, or 5 mph of current, to get the blades moving in order to start the energy creation. As with all renewable resources, there are controversies. One of the main problems that has risen with these turbines is possible biological build-up as well as the potential to change to the marine ecosystems by creating a disturbance within natural lifecycles within the ocean.


Water turbines (Source Institute of Marine Affairs)

Ocean current has also been studied by the University of Michigan, but in a different way. They have created a “device that acts like a fish that turns the potentially destructive vibrations in water into clean, renewable energy.” What is so innovative about their design, named VIVACE (vortex induced vibrations for aquatic clean energy), is that it can create water in flowing water moving slower that two knots or two miles per hour, whereas the turbines already investigated need five to six knots. This is very ground breaking, as this device can be placed in oceans as well as rivers and other smaller water sources since it needs only a low speed of moving water.


VIVACE device (Source: University of Michigan; photo by Omar Jamil)

Although this device does not actually look like a fish, the horizontal cylinders placed in the current will “cause alternating vortices” which will “push and pull the passive cylinder up and down on its springs, creating mechanical energy. Then, the machine converts the mechanical energy into electricity.” Michael Bernitsas, a professor at the University of Michigan, stated that “if we could harness 0.1 percent of the energy in the ocean, we could support the energy needs of 15 billion people.”

Since 2004, ORPC (Ocean Renewable Power Company) has been involved in this newer source option by developing technology that uses “ocean and river currents to produce clean, predictable electricity to power our homes and businesses while protecting our environment.” The company includes local communities, universities, environmental agencies, fishing industry groups, and other major stakeholders in their work during each project. A major project this company has created was ORPC’s Maine Tidal Energy Project.  Starting in 2006, this project has brought in more than $21 million into the state’s economy and has created or helped retain more than 100 jobs in 13 Maine counties. This company has worked on projects in other places including Nova Scotia, Florida, and Alaska.

Have you heard about this potential source before? What do you think about Hydrokinetic energy versus hydroelectricity? Do you think this is something that could, after more research, become a potential energy source we will rely on?