From psalms to odes to sonnets, literature frequently alludes to the awesome power of the oceans. Yet observant writers are not the only ones who understand the overwhelming strength found in the seas. Many shipwreck victims can do likewise, as can former owners of beachfront properties. This understanding is not lost on scientists. They measure the global potential of surface wave energy to equal roughly two terawatts (TW), i.e. two-trillion watts. While holding promise, wave energy is not without complications.
Pros of Wave Power
As mentioned above, wave energy can afford an enormous amount of power to the world. If, for example, a large country like the People’s Republic of China consumes nearly four-million watts of electricity per hour, over half a year would elapse before this massive nation-state exhausts two TWs. This seemingly boundless supply serves to augment already available energy supplies and address shortages where they may arise.
Such supplies would be a boon to poor island nations and developing coastal countries that can little afford the cost of petroleum and have no infrastructure to refine it. Indeed, harnessing wave energy could conceivably change economic and geopolitical relationships around the world. Such a volume of new electricity is a plus when calculating the pros and cons of wave power.
There is no doubt that wave power is renewable. As long as the earth continues to rotate on its axis and the moon persists in its orbit, oceans will produce waves. Unlike fossil fuel materials, wave will never face depletion (unless a serious disruption occurs in our solar system). The pros and cons of wave power tilt toward the positive when this fact presents itself.
As non-renewable sources like coal continue to shrink, they, of course, become more expensive to purchase. On the flip side, as renewable energies like wave-generated electricity are improved by technology, their cost diminishes over time. This benefits everybody.
The pros and cons of wave power again lean favorably when the environmental advantages come to the fore. Wave-generated electricity emits no atmospheric pollution and no undersea contamination. Accordingly, it is an important alternative to energy materials that release greenhouse gases and contribute to climate change. In addition, there is no waste in the generation process—nothing to spill, leak or bury.
Considering the side-effects of purportedly “clean” energy like nuclear, surface wave conversion produces little anxiety. The used rods and contaminated water from atomic energy plants are a constant burden to manage and dispose of. Waves are free of such concerns.
There is never a cessation of wave activity in the world. Yes, tides ebb and flow but waves continue at varying intensity. Professional engineers developed numerous technologies to capture this power. Terminator devices, for example, are on-shore instruments that reach into the direction of waves. Attenuators, on the other hand, float on the water while their segments absorb the wave energy, transmitting it to built-in generators.
Whatever structure does the job, surface motion and sub-surface pressure furnish the energy, which is more or less constant. This gives wave power an edge over renewable sources like wind and solar. These commendable forms are nevertheless prone to interruption. Among the pros and cons of wave power, its transmission is unbroken.
Cons of Wave Power
For all of the pros and cons of wave power, we can’t ignore the cost of production. The technology is in need of improvement—for all the potential energy in waves, only a small portion is currently recoverable. Again, using solar and wind as comparisons, wave technology is pricier by a factor of 1,000 percent. Furthermore, current recipients of wave electricity pay a full five cents more per kilowatt hour than those receiving fossil fuel-generated voltage. This is a strong indicator of its costly infrastructure.
Wherever wave energy apprehension devices are located, there are environmental consequences. The capture of energy offshore means less of it near the shoreline. Marine biologists see disturbances because of this: changing distribution patterns of food dispersal; upset frequencies of egg and sperm contact; and significant temperature changes, to name a few. Sediment accretion will differ, too.
Conceding the positives among the pros and cons of wave power—cleaner and safer for humanity—the generating devices will doubtless change undersea habitats. Whether the sea creatures can adapt successfully remains to be seen.
Sometimes waves can pack too big of a punch, even for wave energy converters. Marine environments may suffer high winds and powerful currents. Both fixed and floating devices can take a beating and require frequent and extensive repairs. Once again, the outlays for such service are often passed on to the customer.
To be fair, most energy generators need fixing every now and then. That acknowledged, wave energy converters are still works in progress. Their restoration is an intensely involved process.
Many wave energy conversion generators are placed at remote sites to optimally capture the power of the ocean. There is a downside to this isolated placement, however. It puts the source far from the destination, i.e. the grid and the population. Making the necessary connections to far-flung places is possible, but difficult, requiring greater financial investment.
Another reason the devices are located in outlying areas is so that they do not disturb other economically advantageous activities like tourism, commercial fishing and aquatic recreation. Salinity levels play a role, as well, affecting overall wave conversion operations.
The Bottom Line
Should wave energy continue its place among renewable energy alternatives? Evidence of its promise is strong. Given that, oceans are ecosystems that provide much more than electricity. Maintaining the integrity of their habitats and processes is essential for life on earth.
Like other forms of energy, wave power may become cheaper as technological research proceeds. Perhaps the best stance to take is cautious optimism while avoiding irrational exuberance. With its compelling potential, we shouldn’t ignore wave power…or embrace it unreservedly.