Energy Source of the Future

¶ … alternatives to traditional fossil fuels, and evaluate them based on their relative availability, renewability, and known environmental impacts. We begin with a baseline characterization of fossil fuels, and outline some of the factors contributing to their current market and industry dominance. We then examine three of the current most prominent and viable renewable alternatives to fossil fuels, including the controversial nuclear energy technology and two emerging technology areas, wind power and algae-based bio-fuels.

Subterranean petroleum-based resources which are currently extracted via drilling and other methods also originated as living algae albeit hundreds of millions of years ago, which accounts for their categorization as "fossil" fuels along with other hydrocarbon-based deposits including coal and natural gas. The combined fossil and renewable biofuels worldwide market was estimated at $5.8 trillion dollars in 2010, of which approximately $1.5 trillion was based in the United States. The cost per unit weight of fossil-based fuel production is very low, at about $0.60 per pound for gasoline that retails at $4.00 per gallon. This is a result of the very high efficiency achieved by the established industry and petroleum refinement technology, and presents a challenge for newer alternative energy technologies attempting to compete with the cost efficiency of petroleum and fossil fuels. This cost factor becomes compelling at the very high commercial production volumes involved in global energy consumption, and sets a high standard of production efficiency for renewable energy production methods to be viable.

About one fifth of the United States' electrical consumption is currently generated via nuclear power. Nuclear reactors produce heat through controlled nuclear fission chain reactions. This heat is then used to turn water into pressurized steam, which then drives turbine generators to generate electricity. Two prominent types of nuclear generators include pressurized-water reactors and boiling-water reactors. Pressurized-water reactors account for about three-quarters of the nuclear reactors in the United States, while boiling-water reactors account for the remainder. Pressurized-water reactors are distinguished by the fact that the radioactive water heated by the reactor core always remains in a liquid state, and is used to generate steam from clean water by transferring heat energy from radioactive water via a network of tubes to the clean water that drives steam turbine generators. Boiling-water reactors on the other hand incorporate a system where nuclear-heated radioactive water and steam are in direct contact with the power generation turbines (U.S. EIA).

Although the U.S. Nuclear Regulatory Commission had more than twenty five applications pending for new nuclear reactors in early 2011, approval decisions have been impacted by the catastrophic failure and ongoing radiation leakage from the tsunami-damaged reactor in Japan in 2010. Whereas the means and technology do exist to increase the use of nuclear fuels and energy production, the latent risk of unacceptable environmental impacts has slowed near-term proliferation while governments and regulatory bodies re-evaluate existing standards and procedures. This approval process is anticipated to require an additional three to four years to complete. Combined with the typical five to seven years required for constructing a nuclear reactor, the prominence of nuclear power is expected to decline from the 20% share of the overall net electric power capacity of the U.S. market it enjoyed in 2010 (U.S. EIA).

Two viable alternatives to fossil fuels and nuclear energy which are rapidly gaining prominence include algae-based biofuels, and wind energy. For each of these, we will discuss the aspects of availability, renewability and environmental impact.

The current focus on algae as a renewable energy resource consists of harvesting living organisms which may occur in natural bodies of water ranging from ponds to rivers to oceans, or are cultivated in artificial water containment facilities. Algae for the purpose of biofuels production may be regarded as eukaryotic, photosynthetic, aquatic-based organisms. The three main components of algae include lipids or oils, proteins and sugars. Algae-based sugars can be used to create alcohol-based biofuels, while algae-based lipids and oils may be converted into biodiesel.

At the simplest level, algae may be any photosynthetic organism that grows in any body of water ranging from artificial ponds to lakes, rivers and oceans. Current estimates are that there are on the order of three million different species of algae, which is approximately one hundred times the number of species of known land plants. They can occur at the microscopic scale as unicellular cyanobacteria or microalgae, all the way to multicellular macroalgae like giant kelp. The advantage of algae as an energy source is that it grows easily and prolifically in any kind or quality of water, including salt, fresh, or brackish water. This means that algae provide not only an abundant and perpetually renewable source of energy biofeedstock, but also represents a source with extremely high genetic and ecological diversity. Cultivation of algae is environmentally beneficial, as algae currently account for 50% of the world's oxygen production, but constitutes less than 1% of overall plant biomass on the planet (Valone)

Wind-generated electric power is presently one of the fastest-growing new energy sources. Since wind is a byproduct of solar heating of the earth's atmosphere, it is an indirect form of solar power. Wind generators harness the kinetic energy from moving air by using wind turbines to convert this energy into mechanical and subsequently electrical power. The environmental concerns related to wind power are restricted to the relatively small byproducts of constructing the generators themselves, and a somewhat greater concern regarding the rate of avian and bat injuries and mortalities resulting from the large, exposed turbine blades moving at high speeds in their habitat. In addition there are some concerns about the visual impact of proliferating numerous large terrestrial and oceanic wind farms. Aside from these concerns, wind power constitutes a perpetually renewed, cost free source of energy that cannot be depleted, and does not contribute to greenhouse gas emissions or other air pollutants. The entry barriers to wind power production involve primarily regulatory and land acquisition challenges, but more prominently high start-up capital investments required for machinery and installation site preparation. Once installed and operating, wind power ultimately offsets the harmful emissions and carbon dioxide production of energy produced equivalent fossil fuel methods, and eliminates the troublesome waste generated by nuclear fission methods. ("Wind Energy Guide")