Energy from waves?


There’s so many wave power companies and as many different devices, so finding one that actually works best is trial and error.
— Mark Jacobson, Stanford University Professor

One Israeli-based company, Yam Pro Energy -- believes it can offer the ideal solution and is set to build a wave-energy plant on the coastline of Accra, Ghana's capital city. 

Wave power is the transport of energy by windwaves, and the capture of that energy to do useful work – for example, electricity generation, water desalination, or the pumping of water (into reservoirs). Wave energy, also known as ocean energy or sea wave energy, is energy harnessed from ocean or sea waves. The rigorous vertical motion of surface ocean waves contains a lot of kinetic (motion) energy that is captured by wave energy technologies to do useful tasks, for example, generation of electricity, desalinization of water and pumping of water into reservoirs.

How is Wave Energy Converted into Electricity?

As the wind glides over the ocean surface, a fraction of the kinetic energy from the wind is shifted to the water beneath, resulting in waves. As a matter of fact, the ocean could be seen as a gigantic energy storehouse collector conveyed by the sun rays to the oceans, with the waves transporting the conveyed kinetic energy across the ocean surface. With that in mind, we can safely conclude that waves are a form of energy and it’s the same energy, not water that glides over the surface of the ocean.

These waves are able to travel throughout the expansive oceans without losing a lot of energy. However, when they reach the shoreline, where the depth of water is considerable shallow, their speed reduces, while their size significantly increase. Ultimately, the waves strike the shoreline, discharging huge quantities of kinetic energy. Peretz said their technology was much more efficient than other renewable energy sources because it can generate 65% of energy per year, compared to solar panels and wind turbines which generate between 22-24%. "The rest is heat and just waste," Peretz said. 

The advantages of wave power, the company argues, is that their machines do not emit pollution, waves are more predictable than other renewable sources and despite the original set up being costly, the running and maintenance costs are low.

"If the waves are too high we are given forecasts days ahead which helps to analyze the situation," Peretz said. While construction in Accra won't begin until well into 2017, Yam Pro Energy has already secured the coastline to build its power station. It has also teamed up with local partners, secured its power purchase agreement (PPA) from the local electrical company and has been given space on the grid so it can sell the energy produced. Peretz said 10,000 households will benefit from the project.

The Solutions Project predicts that if Ghana can transition to 100% clean, renewable energy by 2050, wave energy will account for 1.4 per cent of it.  "The amount of energy worldwide is enormous. So something that is large is actually small in comparison to the power demand worldwide."

"These countries can become more energy independent. There's less risk of conflict, less terrorism because there's fewer centralized plants and you solve the climate problem simultaneously." IRENA's Taibi was more optimistic. He said that while the growth of wave power has been gradual, it was only "a matter of time" before it became the "sixth pillar" of renewable energy that will become commercialized.