Cooper Sloan '22: Entrepreneurship Learning Competency

Economical Energy Can Be Small

As the world transitions to using more sustainable energy sources, experimental ideas for sustainable energy production are beginning to see new developments. One of those ideas is capturing the kinetic energy from ocean waves to generate usable electricity. The biggest obstacle for marine hydrokinetic generation is that, currently, it is not economically feasible (Dincer, 556). As with any novel technology, however, economic feasibility follows research and development of the technology itself, along with infrastructure to manufacture said technology.

The current model of our electricity grid is one where large-scale power plants (coal plants, wind and solar farms, dams, etc.) produce large amounts of energy to send to the grid. From there, electricity can be distributed to any building on the grid, even buildings hundreds of miles away. This model of electricity generation places a huge dependence on these power plants, meaning that if one source were to fail (from natural disasters, attack from foreign powers, etc.) then the effect would be immediate and catastrophic. A clear example of large-scale energy plant failure is the 2021 Texas energy crisis, where snow storms caused failure of natural gas plants, causing energy and water shortages across the state. As an aside, Texas has an electricity grid separate from the rest of the nation, making it challenging for Texas to import energy from other states, which ultimately worsened the 2021 crisis. If the electricity grids were supplemented with small-scale power generation, it could diversify and bolster the energy grid, while reducing the demand on large-scale power plants.

Small-scale energy generation, in the form of an oscillating water column, was the topic of my capstone project. Imagine holding a large hollow tube vertically in the ocean, not allowing the tube to move in any direction, and submerging only the bottom of the tube. When an ocean wave (or swell) rises, air will be pushed out of the top of the tube. Then when the wave falls, and water voids the tube, air will be sucked back into the tube. Now, if you put a turbine in the middle of that tube, you could conceivably create power. This is the concept behind how an oscillating water column works. The oscillating water column that my capstone team and I developed was designed to float, as a standalone buoy, anchored to the seafloor at the trough of a predictable ocean wave site. Using a bidirectional impulse turbine, along with guide vanes to help direct air, our team was able to formulate a design that rotates the turbine in the same direction, regardless of whether the air is flowing up or down the tube. The oscillating water column was sized to generate 5 watts of electricity which, for context, is the amount needed to charge an iPhone. According to the U.S. Energy Information Administration, the current cost of electricity in Oregon is 8.82 cents per kilowatt-hour. Given that our oscillating water column took about $800 to fabricate, and that it generates 5 watts, it would take about 207 years for this project to pay for
itself. Granted, our oscillating water column is a prototype developed in a matter of months by non-professionals, but it goes to show that there is a significant barrier to creating economically viable energy from ocean waves. Given more time and funding, the inefficiencies of the oscillating water column could be reduced, as well as the cost of manufacturing. As an additional consideration, the functionality of the oscillating water column can be drastically altered. For example, using water as the fluid to rotate the turbine would yield a higher power output because water is a denser fluid than air. However, this would require the electrical components (such as the generator and circuit) to be waterproofed, ultimately raising the upfront cost of the project. While raising the upfront cost of the project increases the time it takes for the project to economically break-even, using water would theoretically increase the power output which, in turn, reduces the break even point. This type of economic analysis can be used as a tool to justify the design choices of the oscillating water column.

While oscillating water columns may never become our primary energy source, there are plenty of applications where it could conceivably be useful. For example, navigation beacons, weather beacons, and even some warning buoys all use electricity. If these buoys were self-sufficient in their energy needs, then they would not need to be connected to the energy grid, thereby reducing the strain on large-scale power plants. This reduced energy demand would, to a certain extent, reduce the cost of energy for homeowners, businesses, etc. Furthermore, if warning buoys (or other essential equipment) were self-sufficient energy-wise, they would be immune to any power outages that the electricity grid may experience. This concept of self-sufficient machinery, or even partially self-sufficient machinery, can be applied to other areas as well. For example, rooftop solar panels supplement a homeowner’s energy needs, ultimately reducing their (and to a lesser extent, others’) energy bill.

Something that must be considered, however, is that creating a built-in energy source for every piece of technology that we use may not be more sustainable than having a few high-efficiency power plants that generate energy for the grid. As with all technology, solar panels, oscillating water columns, and the like all require raw materials which take money and power to acquire. Not to mention, raw materials are a finite resource that should be used cautiously. An economic analysis of any engineering project should not be grounds to overlook an environmental analysis. I would argue that since the state of the environment (which includes the state of raw materials) directly affects the cost of natural resources, a proper economic analysis must consider the environmental impacts of a project.

While there will likely never be a world in which every machine is independent, there can be a world where small-scale energy supplements the energy grid in a significant way. As we move to minimize the use of fossil fuels and diversify our sources of energy, the role of small-scale energy generation should not be overlooked. And while small-scale energy can be used in niche
applications, it cannot do so without the investment of quality research and development to maximize economic payout.

Dincer, Ibrahim. Comprehensive Energy Systems. Elsevier, 2018.

EIA. “Oregon Electricity Profile 2020.” EIA, U.S. Energy Information Administration, 4 Nov. 2021, https://www.eia.gov/electricity/state/oregon/.