As a young surfer from Southern California, all I knew about ocean waves was the Beach Boys, Surfboards, and Woodies.
And yet, the gigantic amount of kinetic energy that exists within 50 miles of 50% of the world’s population presents almost limitless renewable energy opportunities to help reduce our dependence on carbon products.
North Bay counties in the Pacific Ocean could produce unlimited energy if they harness energy from the ocean on their shores.
With around 70% of the earth covered by oceans, their powerful currents below and on the surface have literally moved continents for ions, but capturing this energy is not easy. Strong currents can literally destroy the most powerful buildings and mechanical equipment.
On top of that, salt water corrodes, sea creatures and barnacles cling, and storms can destroy an electrical system in minutes.
The capture of ocean wave energy, OWEC, is not new, but as renewable energy sources expand and the quest to neutralize our carbon footprint grows, the OWEC becomes a new goal. The objective is to produce electricity to supply our electrical networks.
Similar to hydroelectric power plants producing power by using stored water rushing over a dam to propel turbines, OWEC would harness the constant energy of waves on the surface or at the bottom of the ocean, acting in the both directions.
Oscillating water columns: A cylindrical shaft collects the air driven by the waves through the shaft like a bellows to generate electricity.
Surge protection devices: A conical channel channels the waves into an elevated reservoir where the water returns to the ocean via a conventional hydraulic turbine.
Floating devices: Underwater turbines attached to a system of buoys which rotate under the action of the tides and generate electricity connected to the network.
Differentiation of seabed pressure: One of the most promising ventures are ocean floor mounted devices that exploit the pressure difference of ocean currents so as not to receive the violence of ocean surface waves.
As with all renewables, there are pros and cons.
1. A permanently renewable and sustainable source of energy, ocean tides are the result of sunlight, the earth’s rotation, combined with gravity.
2. Environmentally friendly with no energy or carbon emissions, while continuously generating electricity directly into the power grid.
3. Abundant, more reliable and consistent than other renewable energy sources. Ocean currents move 24/7 around the world.
4. Water being denser than air, it is possible to produce more energy to generate electricity even at low tide.
5. Less visual impact: Power plants or factories could be built offshore and, unlike oil rigs, would have little or no visual impact without any environmental impact due to explosions or leaks.
1. The cost of the initial installation can be high, unlike the average solar panel in a garden. Larger scale research and surveys are needed.
2. Limited locations. Many of the best locations for factories are in existing urban or tourist destinations. Although less visible, it can be difficult to minimize visible installations.
3. Although among the cleanest and least harmful to marine life, more research needs to be done to protect our ecology and our delicate habitats. Any use of chemicals should be carefully considered for unintended consequences.
4. Scalability difficult. Creating utilities, equipment and supply lines to provide enough energy will be the real challenge.
To date, there is no commercial exploitation of wave energy. However, joint ventures between some US companies and Australia are expected to create enough electricity for 10,000 homes off their coasts.
Although the capture of ocean tidal waves has the greatest potential for producing renewable energy, there is still a lot of research to be done. As they say, “Catch a wave and you are sitting on top of the world!” “