The world's oceans possess enough energy to meet the demands of 6.25 Earths. But how can this wave energy be converted to useful electricity?
Wave Power Density
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Oceans cover 75% of the world's surface. Power generation from waves, tides, currents, salinity and thermal gradients has the potential to generate 100,000 TWh/year. Today's technology can harness about 1,400 TWh/year.
Conversion of ocean energy resources could help lead to energy independence and a reduction in greenhouse gas emissions.
The most energy rich regions are located between 40 and 60 degrees latitude where 30-70 kW/m is commonly seen with peaks occasionally reaching 100 kW/m of annual production.
Conversion of ocean energy resources could help lead to energy independence and a reduction in greenhouse gas emissions.
The most energy rich regions are located between 40 and 60 degrees latitude where 30-70 kW/m is commonly seen with peaks occasionally reaching 100 kW/m of annual production.
Our Project
Our original goal was to investigate/come up with alternative wave power generators. However, after searching the web, we quickly realized that even our best ideas were already patented... This lead to a refining of our scope. We would study all current technologies to find the "best" wave power generator. Ideally, it would be easily deployable, durable, efficient, and require a minimal spacial footprint. This didn't work either, as we discovered that what works best off of the coasts of Europe may be ill-suited for the Pacific Coast of the USA. |
After continued research, we discovered Ocean Power Technologies' proposed Coos Bay wave farm project, which will produce an estimated 275,000 MWH annually. This project will harnesses wave energy using buoy-like devices that rely on hydraulic power takeoff (hydraulic fluid compressed with wave energy and used to turn gears/ generators). Due to the fixed gearing of these buoys, the generators can only harvest a certain percentage of the available wave power; during very large or small wave events, energy is wasted to protect the electronics from under or overloading. Additionally, this system utilizes many moving parts and hazardous fluids, thereby potentially adding to wave power's growing reputation of inefficiency, unreliability, and lack of economic feasibility.
Due to these shortcomings, alternative power take off systems have been considered and are currently being developed. The most promising technology is linear inductance generation, which functions by passing a permanent magnet through an electric field to induce an electric current. In the past, the magnetic materials and control devices required for these systems were extremely expensive; advances in materials and electronics technology, however, have made the voltage regulating devices needed to operate these systems within reach. Finally, we determined a purpose for our project: to compare the efficiency gained by using linear inductance generation systems over traditional hydraulic power take off systems. Specifically, we would compare these two systems in a real-world application: the proposed Coos Bay, Oregon wave park. We wanted to analyze the gains that could be seen in each of the following categories: -Efficiency in generation by simplifying from a 6 transfer system to 3 (see power takeoff systems diagram to the left) -Gains from increased control and more efficient dampning -Gains in durability and reliability Additionally, we wanted to find an estimate on what the cost difference would be to implement a linear inductance system as opposed to a hydraulic one. Our final recommendation would be whether or not to implement linear power takeoff systems at the Coos Bay, Oregon wave farm and to discuss how we reached our conclusion. |