Wave and tidal power ranks #29 on Drawdown’s list of climate solutions. By 2050, this alternative energy source could eliminate 9.2 gigatons of atmospheric carbon dioxide at a cost of US$412 billion. Drawdown calculates that the installations would produce a net financial loss of $1 trillion over three decades, but the investment would result in substantial emission reductions over that time.
Wave and tidal energy systems create electricity using the power of the ocean’s natural flow. The technology is attributed to the invention of the oscillating water column (OWC) in 1947 by Japanese naval commander Yoshio Masuda. Electricity is produced when a wave or tide enters an OWC and moves air through a turbine.
Drawdown reports that certain parts of the globe have greater potential to produce this kind of energy, noting that the west coast is the best coast on all continents to produce wave energy. For tidal energy, the United States’ northeastern coast, the United Kingdom’s west coast, and South Korea’s shoreline (not to mention Canada’s Bay of Fundy) are all ideal locations.
Waves and tides are among the most powerful and constant natural sources of energy on the planet, Drawdown states. However, they only provide a small share of the world’s energy supply, and using the ocean as an energy source creates several, often expensive, challenges. The ocean is a rough environment, and equipment can be damaged by salt water and wave turbulence. And as much as wave and tidal systems must be sturdy and effective, they must also be designed with care, to avoid harming or disturbing marine life.
In general, this technology is still developing, and moving at a slower pace than solar and wind. With basic testing still under way, the most effective wave and tidal energy systems are yet to be determined. As for siting, “oscillation is the key,” Drawdown notes, “so the higher the wave, the greater its power potential tends to be.”
Advancing wave and tidal power as a renewable energy source will require big investments and more research. But if the technology reaches its potential, experts say this option could meet 25% of electricity demand in the U.S., 30% in Australia, and 70% in Scotland. With the support of public policies and private investment, wave and tidal energy can become an accessible, cost-effective alternative to fossil fuels.