For those of us who have toiled in marine energy startups, we know the challenges of converting the immense energy-producing potential of the oceans into a viable power resource. The ocean holds great promise – water is 1,000 times denser than air, and the technology already exists to harness this energy without harming fish or other marine species. The issue for ocean energy, absent a major financial or legislative push behind the industry, is a practical one: how to get all of that power from its source (the water) to the electric grid.
The potential payoff of a legitimate commitment to ocean energy, at least in the nation’s coastal areas where tides are strongest, should absolutely be considered as part of any truly comprehensive energy policy for the 21st century. In the meantime, however, and in a national legislative climate that is less-than-friendly to investments in the renewable energy sector (see Solyndra: stay tuned for more), it is up to creative individuals and organizations to make due with the resources that are currently available.
One of those such organizations is the United States Navy, which recently began using ocean waves to power vessel-detection buoys off the coast of New Jersey. The buoys, which are part of a more extensive maritime surveillance system that helps protect the country from terrorism, used to be powered by diesel generators. Now the Navy relies on the motion of the ocean to move hydraulic fluid inside the buoys, which spins the generators instead of diesel fuel. In total, one buoy can supply up to 50 kw of electricity, which is enough to power a dozen or more US homes. Instead of facing the logistical challenge of moving this energy to shore, however, it can be used where it is produced to benefit the Navy (no transport costs for diesel fuel to power the generators), the ocean (no leaked diesel fuel), and the air (no diesel fuel emissions).
One of the central questions for ocean-going energy systems – how they might fare in severe weather – appears to have been answered in August when several of the Navy’s New Jersey buoys survived a direct hit by Hurricane Irene and withstood the 50 foot swells that came with it.
Navy uses waves to power sensors (Scientific American)