Renewable Energy Resources

From dealing with a changing climate to attempting to reduce dependence on foreign sources of energy, renewable energy promoters can be found around the world.

Five energy sources fit into the renewable category:

• Biomass
• Water (hydropower)
• Geothermal
• Solar
• Wind

In some instances they are used to generate heat or used as fuel in the transportation industry, with solar power and biomass two of the better known vehicle fuels.

Providing general descriptions for all five renewable energy categories tends to be a straightforward task. Solar power, for example, can easily be understood as energy from the sun. The complexity comes in understanding how scientists go about gathering and transforming the energy into electricity.

Large scale solar power plants, for example, can be designed using solar thermal technologies or Concentrated Solar Power (CSP) technologies.

From sun to surf, the country's first commercial wave energy farm became a reality when a group of public and private investors working with PNGC Power, a Portland based company, inked plans for the installation of a 1.5 MW wave-power project, to be situated two and one-half miles off the coast of Reedsport, along the central Oregon Coast.

The concept of wave energy farms resembles the concept of offshore wind farms, with the exception that this particular wave farm will be buoy powered.

The technology underpinning the PowerBuoys is relatively simple. One hundred and fifty foot buoys with hydraulic systems are planted in the seafloor. Waves move the hydraulic system, generating electricity. A cable connecting the buoys to onshore transmission lines completes the process.

Environmental concerns associated with offshore wave farms mirrors the concerns associated with offshore wind farms.

Offshore construction projects can potentially change the ecosystem of their surrounding environment. Placing large objects on the ocean floor, for example, poses a potential problem for the benthic animal population. Likewise, a large man made structure in the ocean could potentially confuse migrating whales.

The placement of man made objects along the coast could potentially change wave patterns and subsequently shorelines.

Oregon's wave energy farm only plans for the installation of ten PowerBuoys, creating less of a probability for any significant long term environmental damage. Nonetheless, the wave farm will be monitored for both anticipated and unanticipated environmental problems.

Project supporters also face technical challenges. The PowerBuoys chosen for the project have preformed well in limited testing environments, usually over the course of a year. Because Oregon's project will be the country's first commercial wave energy farm, both anticipated and unanticipated longer term buoy maintenance problems must also be monitored.

Wave energy's potential downside could very well be outmatched by its upside.

According to researcher's at Oregon State University, "Wave Energy has several advantages over other forms of renewable energy such as wind and solar including higher energy densities, enabling devices to extract more power from a smaller volume at consequent lower costs and reduced visual impact (e.g. the density of water is about 832 times that of air). In addition, waves are more "available", an indicator of how often the "waves roll" (for wind, how often the "winds blow"). Wave energy availability is in the 80-90% range, whereas wind availability is in the 30-45% range depending on location. Wave energy is also more predictable, with energy forecast times of greater than 10 hours, thus enabling more straightforward and reliable integration into the electric utility grid to provide reliable power."

The links in the box on the right point to articles that provide additional resources about general renewable energy and energy efficiency issues.

© 2001-2012 Patricia A. Michaels.