As a young Southern California surfer, all I knew about ocean waves was Beach Boys, surf boards and Woodies. And yet, the sheer amount of kinetic energy that exists within 50 miles of 50% of the world population presents an almost unlimited renewable energy opportunities to help reduce our dependence on carbon products.
With roughly 70% of the earth covered with oceans, their powerful currents below and on the surface have literally moved continents for ions. But capturing that energy is not easy. Strong currents can literally destroy buildings and the strongest mechanical equipment. On top of that, salt water corrodes, sea creatures and barnacles cling and block in-takes and storms can destroy a power system in minutes.
Ocean Wave Energy Capture is not new but as renewable energy sources are expanding and the quest for neutralizing our carbine footprint gains momentum, OWEC becomes a new focus. The objective is to generate electricity to energize our power grids. Similar to hydropower plants creating power using stored water rushing over a dam to propel turbines, OWEC would harness the constant wave energy on the surface or at the ocean floor, acting in both directions.
Oscillating water columns: A cylinder shaft collects wave driven air through the shaft like a bellows to make electricity.
Wave surge devices: A tapered channel funnels waves into an elevated reservoir where water flows back to the ocean through conventional hydro turbine.
Floating devises: Underwater turbines attached to a buoy system that spin from the tidal action and generate electricity connected back to the grid.
Ocean Floor Pressure differentiation: One of the most promising ventures is ocean floor mounted devices that exploit the difference in pressure of ocean currents so as to not receive the ocean surface wave violence.
As with all renewable energy resources, there pros and cons:
A continuously renewable and sustainable source of energy, ocean tides are the result of sunlight, the rotation of the earth, combine with gravity.
Environmentally friendly with no energy or carbon emissions while generating continuous electricity directly into the power grid.
Abundant, more reliable and consistent than other renewable energy sources. Ocean currents are 24/7 around the world.
Since water is denser than air, more energy can be produced to generate electricity even at low tides
Less visual impact: Energy stations or plants could be constructed offshore and unlike oil platforms, would have little or no visual impact with no environmental impacts from explosions.
The cost for initial set up can be steep, not like the average backyard solar panel. More large-scale research and investigation is required
Limited locations. Many of the best location for plants will be in existing urban or tourist destinations. While less visible, minimizing visual facilities could be challenging.
While among the cleanest and least harmful to sea life, more research must be done to protect our delicate ecology and habitats is essential. Any chemical uses must be carefully studied for unanticipated consequences.
Challenging scalability. Creating utility companies, equipment and supply lines to provide sufficient energy will be the real challenge.
As of today, there are no commercial wave power operations, however joint ventures between some American firms and Australia are posed to created enough power for 10,000 homes off their coastline. While ocean tidal wave capture has the greatest potential for producing renewable energy, there is a lot more research that needs to be done.
As they say…..
“Catch a wave and you’re sitting on top of the World!”
Chris d Craiker AIA/NCARB, will be visiting a Kauai OWEC….and perhaps a Mai Tai or two.