Page 66 - North American Clean Energy May/June 2020 Issue

energy efficiency
The potential of the global ocean’s resources is mind-boggling. Between large water surfaces and marine resource diversity, there are a wide variety of energy extraction options available.
Recently report by Ocean Energy Systems (OES), the global wave and tidal stream energy production has risen ten-fold over the last decade. The density of wave energy could even equal the offshore wind sector, considering that waves are a concentrated form of energy capable of travelling large distances with minimal losses. Curiously, we have barely tapped this promising sector of the clean energy market.
Supplying Demand
The theoretical global potential of wave power is around 29500 TWh/yr, from which currently only a small fraction is extracted near ocean coastlines, islands, or semi-enclosed basins.
If we take 2 percent of the world’s 800, 000 kilometers of coastline with a wave power density of 30 kilowatts per meter (kW/m), and an estimated global technical potential of about 500-gigawatt electrical energy (GWe) – based on a conversion efficiency of
40 percent – by just utilizing 2 percent of our coastlines, we can generate 4,383TWh of ocean power annually, enough to meet 16.4 percent of the world’s electricity needs.
In the European marine energy market, the successful development of marine energy technology could generate 188 GW (10 percent) of Europe’s electricity needs by 2050. For this to happen, wave energy deployment would begin in 2022 – just two years from now. One promising option is bringing together wave energy devices with existing coastal onshore wind farms by connecting and sharing the onshore localised power hub and grid infrastructure. This would help accelerate and develop wave industry in areas with moderate wave energy potential.
Market Opportunities and Storing Energy
In summer, California renewable power production comes from both the sun and the wind (wind courtesy of hot desert days). But winter sees a big drop off in this power production. Given the 80 percent renewable scenario, the gap in December is about five terawatt hours. California could store energy in the summer and deliver it to the grid in the winter, but the amount
of rare materials you would need for that amount of storage is mind-boggling. Five terawatts hours is the same
amount of wave energy coming into 70 miles of coastline in the winter months. That gap between the summer and winter can be filled with wave energy, which could help deliver renewable energy across all seasons.
Predictability
Compared to wind and solar, wave energy is highly predictable. Decades of marine engineering has driven advances in weather simulations that has given us the ability to accurately predict wave energy. In the major oceans, it’s possible to predict wave energy about a week ahead. About two weeks for the tropical oceans. With wave energy, we could have the prospect of selling next week’s renewable energy.
LCOE or LVOE?
As more solar comes onto the grid, when it’s sunny, solar competes with itself.
Each new solar panel you put in it will compete with the others. And you see the same in wind as well where the levelized cost of energy is called in to question. However, wave energy is considered not as a competing industry, but rather an indispensable addition to the renewable energy mix. With energy production more closely matching the demand, it will result in a higher levelized value of energy for the owner or operator.
Not a “one type fits all” approach
There is no one technology that can
meet all the requirements we demand;
a team effort will bring optimal results. Wave energy will play an important role, complementing other renewable energy sources to create increased grid stability. In Chile and Australia, for example, the amount of wave energy coming into the coastline is far greater than the electricity demand in the country. California’s waves can easily fill the winter shortfall left by both wind and solar.
Making Waves
Transforming the renewable energy mix
by Christopher Ridgewell
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MAY•JUNE 2020 ///
www.nacleanenergy.com