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.

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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.

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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.

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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?

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10 thoughts on “Energy in the current?

  1. kvsims says:

    I have been introduced to hydrokinetic power but never heard of the method being applied in a river system. The idea of tapping into such a vast energy source intrigues me. “The nonprofit Electric Power Research Institute, whose members represent 90 percent of the nation’s utilities, has estimated that in the United States alone, new hydrokinetic technologies could provide an increase in generation capacity of 3,000 megawatts by 2025. Another study found hydrokinetic energy could supply 10 percent of America’s electricity needs.” Hydrokinetic power introduces a currently untapped renewable, energy source that produces no emissions. In some ways it seems like the perfect renewable energy source. The only downfalls seem to be the reliability of the current technology and parts and the effects on the ecosystem. I believe over time the issues of the turbines breaking due to drastic flow increase will improve as will the technology and materials. As for the effects on the ecosystem, hydropower plants have harmful effects on ecosystems. Fracking, ocean drilling for oil, CO2 emissions all have effects on the environment. Two wrongs don’t make a right – but I don’t believe that we should abandon the technology because of minor effects on the ecosystem. I am not recommending that we install hydrokinetic turbines on a coral reef, but I think using caution the environmental effects of the turbines could be minimal. As Douglas Meffert, a professor of bioenvironmental research at Tulane University, put it “It’s not just an issue of renewable energy; it’s an issue of energy security. We could have a hurricane wipe out our traditional energy grid, yet that river is still flowing. So if we’re tapping into that, we’d be a much more resilient and robust region in terms of our energy facilities.” I think it is very probable with the proper funding and research that we could rely on hydrokinetic energy in the future.

  2. I have heard of hydrokinetic energy technology, but I am not familiar with many details. It certainly has great potential given that the oceans have such a vast amount of energy moving through them at any given time. The varying technologies associated with hydrokinetic energy are fascinating. Several interesting methods can be found here on the Union of Concerned Scientists website. http://www.ucsusa.org/clean_energy/our-energy-choices/renewable-energy/how-hydrokinetic-energy-works.html#2_Hydrokinetic_Technologies

    I feel that this is another renewable technology that needs to be pursued and advanced. If we’re going to push for cleaner energy with wind, solar, biofuels, other renewables, I don’t see why this would also not be included. There are many drawbacks to hydrokinetic energy just as there are with other renewables and non-renewables. I believe that the renewable energy generation portfolio will need to be a diverse portfolio. With improvements made by scientists and engineers, I like to remain confident that this is another renewable technology that will eventually be used to generate electricity on a larger scale.

  3. pfc1344 says:

    I have never heard of hydrokinetic energy, but I am a bit hesitant to say that this will be an energy source that will heavily rely on in the future. If these turbines are placed in areas where the currents in the ocean are the strongest, wouldn’t they be consuming the energy needed to transport nutrients, animals, warm water to other parts of the ocean? If you place something in the middle of some sort of flow, it’s going to disrupt the flow significantly (fluid mechanics). I think there would be more than “minimal” effects on the ecosystem if/when this technology is implemented on a large scale. It would affect the entire ocean, not just the area where the technology is placed. Europe depends on the ocean currents to bring warm air to their area. Disruption of these currents could also hinder the streams to transport “sediment and debris” and could cause “deposition of suspended sediments” which could ultimately “alter bottom habitats”.

    In order to implement this technology on a larger scale, I would be important to determine when the break-even point occurs between the amount of technology in the current and the amount of energy to keep the current operating at a sustainable level. It’s possible that the amount of energy removed over a period of time may ultimately kill the cycle- but who really knows at this point. However, I do think that over time we could drastically reduce the impact on the environment. Overall, I do not think that this will be a technology that will be heavily relied on in the future. I think the potential impacts on such a global scale maybe limit the overall use of this technology.

    Europe Weather- http://www.sciencedaily.com/releases/2011/01/110114155336.htm

    Cada, G., Ahlgrimm, J., Bahleda, M., Bigford, T., Stavrakas, S., Hall, D., & … Sale, M. (2007). Potential Impacts of Hydrokinetic and Wave Energy Conversion Technologies on Aquatic Environments. Fisheries, 32(4), 174-181.

  4. dnlo10 says:

    I have heard of hydrokinetic energy dealing with damns and rivers but I have never thought about using the ocean currents as a energy source. I do think that this could be utilized on a small scale but there will be large environmental concerns if it was implemented on a larger scale. One of the problems is going to be that the velocity of the current will be reduced proportionally to the size and number of units that are used. These slower currents and smaller waves will then increase the sediment deposition. This increase in sediment will alter benthic habitats. Another concern with the units is the new electrical and magnetic fields in the water and sediments that will be formed. These can possible alter feeding behavior. The next concern I want to talk about is the possible interference with migrations which can significantly alter the population of certain marine species. Probably the largest concern would be the transfer large volumes of water between ocean depths. This can alter the nutrients, water temperatures, dissolved solids, and dissolved gas concentrations.

    I know that it sounds like I despise the use of ocean currents for energy but that is not the case. I am simply explaining that there are environmental concerns with using this technology. Like I said earlier, these concerns are mainly dealing with large scale implementation. I do believe that this technology can be very successful if used on a small scale.

    I do believe that the US will not heavily rely on this as a large source of energy because of the environmental concerns. I do however believe that we will use this for small scale energy generation

    http://www.kentlaw.edu/faculty/fbosselman/classes/energysp09/Coursedocs/Hydrokinetic%20Energy%20from%20the%20Ocean.pdf

  5. I have never heard of harnessing ocean currents as a source of energy before. I find this extremely interesting and think that it would be a great source of energy. One of my concerns is that salt water tends to be very destructive so there would problems with erosion and maintenance costs. This means that energy prices might be higher to account for this problem. Another concern, like you said, is the change to the environment. By adding in new structures it changes the ecosystem and could potentially cause a decrease in some species. I think this is something to take into account when thinking about using hydrokinetic energy, but at the same time these problems also surround other sources of hydroelectricity. For example hydroelectric dams, put water back into rivers downstream and this water tends to be “…inhospitable to fish because it is much colder and oxygen-poor” (“Hydroelectricity”). To me this shows that both hydrokinetic and hydroelectric sources of energy have there cons when dealing with the environment. This means that further developments need to be made to ensure that the lesser of the two evils is chosen as a viable source of energy to ensure that environmental destruction does not continue.

    “Hydroelectricity.” EPA. Environmental Protection Agency, n.d. Web. 25 Sept. 2013.
    .

  6. Energy being harnessed from the current has been a major topic for a renewable energy source for a while now. I personally have read about this technology before, but not on an in-depth scale like your post. I believe it is a viable option for our future energy demands, but more research must be performed first. As seen in the Report to Congress on the Potential Environmental Effects of Marine and Hydrokinetic Energy Technologies there are over 100 different conceptual technologies currently in design, but not being tested in a real life scenario. Some of the potential risks associated with this technology are: alteration of current and wave strengths and directions; alteration of substrates and sediment transport and deposition; generation of electromagnetic fields; and interference with animal movements and migrations, including entanglement. These potential risks associated with the technology can have major impacts on local ecosystems and global ecosystems, which can be seen on pages VI and VII in the report to congress. It can be seen that the potential harm to the environment is significant, but with further research and innovations I believe this harm can be minimized to where this technology is a better option than other forms currently in use.

  7. I have never heard of this! It seem so cool. Yeah, there are a lot of uncertainties with the amount of consistency that this technology would have, but the amount of energy that the ocean could provide is huge! This really makes me want to look into the possible effects wind turbines have on taking energy out of wind currents to produce energy. The energy comes from somewhere so are winds so full of energy that what we take from them is negligible or is it something else entirely? This would be the same with the ocean currents, energy-wise at least. What happens when we take away energy from the ocean? Also, other ecological effects of having those devices in the ocean should be considered as well, such as fish trying to consume the devices or similar issues. I think using both hydroelectric and hydrokinetic is important for the future. It doesn’t hurt to have hydroelectric energy in dams when the main purpose of a dam is to control flooding; therefore, hydroelectric power shouldn’t be thrown away. At the same time, there isn’t enough need to have hydroelectric dams everywhere, and this is where hydrokinetic energy can come into play. Hydrokinetic has more of an ability to be placed anywhere, so it is more adaptable to various locations. Distributing the power from hydrokinetic, assuming most of the energy would be from the ocean, could also pose as an issue to its advancement. I definitely think, with advances, that we could come to really use hydrokinetic – maybe not as a primary source, but as a complimentary to main renewable sources.

  8. wavant says:

    I have heard about hydrokinetic power and its viability since it can be placed in the ocean and appears to have less harmful environmental impacts. However, that is about all I knew about the aspect. After doing some research on this topic, it appears that could indeed be a viable option for the future but not in the near future. According to the Sonoma Coast Hydrokinetic Water Feasibility Study (http://www.cmanc.com/web/presentations/Fall2011Presentations/AmyBolten.pdf), it bluntly states that the technology simply is not there right now. In addition, it points out that marine studies are the most expensive studies today and involve a large amount of risk. It also points out additional including the ocean environment on fishing, ocean habitats, and even shipping. However, the study does acknowledge at the end that hydrokinetic energy provides “great promise and hope.”

    Is the willingness to invest that amount of money present within the government when there appears to be more push for solar and wind research and there have been advances in these two sectors? My personal opinion is that yes, there should be money given to this research as there appears to be more room for growth and reach for this area of renewables than for wind power and solar power. Furthermore, all energy projects have some negatives associated with them. Once again, my only complaint (and this comes with any new energy source) is its unprovenness and if it can be counted on to be a reliable energy source for an extended period of time. I think hydrokinetic energy is definitely an avenue that energy companies could definitely travel down in the future as the limits seem negligible, and the energy source appears to be favorable with environmentalists right now. Can this source (like others) get over that initial hump with research is my question?

  9. I am so excited to see that you wrote about hydrokinetic energy! I initially heard about hydrokinetic energy in my APES class in high school. I had completely forgotten about it until now. Overall, I think hydrokinetic energy is a great idea. It is a technology that is renewable, has no emissions, no loss in aesthetic value, and is invariable. It seems like a great alternative; however, as with most renewable alternatives, there are concerns. An article from the Office of Energy Efficiency and Renewable Energy focuses on current hydrokinetic technologies being considered (refer to Table 1), and does a great job at touching on all of the potential concerns (refer to Table 2). With extensive research and testing, many of these concerns can be addressed. I think we need to study the implementation and implications of this technology more, but I definitely think it has great potential.

    Source: http://www1.eere.energy.gov/water/pdfs/amfishsoc-april2007.pdf

  10. shreyasvangala says:

    While VIVACE is ingenious in it’s own way, I can’t say that I think that it is a major energy solution for the critical issues that we face, especially given the potential cost of maintenance and the effects that such continual maintenance could potentially have on aquatic life systems. There will be an inherent tradeoff between maintaining such a system and disrupting algal formations that will likely form on a VIVACE system interfere with its function and efficiency, while also supporting almost all species of aquatic life that are consumers. At present, I see VIVACE as a “luxury” energy generating technology.

    I do believe that the use VIVACE or similar technology in a riparian system has the potential to really solve a number of problems in the developing world in a sustainable manner, especially with regards to developing nations where rivers are highly contaminated and are good for little else (e.g. China and India). Such initial sustainable development would be the ground for future sustainable development.

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