Reading Passage: Alternative Energy Sources

The population recently reached the six billion mark and will continue to grow at an exponential rate in the future. As the population increases, so will the demands for resources like food, water, and electricity. Renewable, clean, and efficient power is increasingly important as limited fossil fuel sources slowly disappear, and pollution becomes more of an issue. However, the industry has already begun to answer many of the tough questions about where our power will come from in the future. Today we are exploring alternative sources of power, and using new technology to make old sources more efficient.

Power companies today have many methods of making power more efficiently. For example, they use a heat rate to measure the efficiency of their power plants. It compares the BTU (British Thermal Units=1055 Joules) consumed with the BTU generated. The lower the number the more efficient the plant. The rate is influenced by the technology of the plant and type of power they use. These factors can vary immensely. Today power plants diversify their portfolio of power sources so that the can produce cheap and efficient power. For example, in 2003, Florida Power & Light's (FPL) energy sources included: 34% gas, 21% nuclear, 19% oil, and 6% coal. Note that the remaining 20% percent were purchased from other power companies.

Image courtesy of Florid Power & Light

FPL has a super computer that directs power to your home in the most efficient way possible. This program, called economic dispatch, calculates the cost of generating power at any given plant and the cost of sending it to a specific location. Then it sends you the most economical power saving both you and the company money. In addition, they can perform energy audits in which they come to your home and inspect your house to see how you use energy and how you could save money.

Today, there are several ways of generating power. Nuclear, hydroelectric, wind, solar, coal, oil and gas, are the most significant methods. Many people believed solar power would solve the world’s energy problems. After all, if we could harness all of the sun’s energy that hit the earth in a one minute period it could power the entire planet for a year. In fact, only a hundredth of a millionth of one percent of the sun’s power even arrives at the planet. Solar power is already used to heat pools and homes and photovoltaic cells convert sunlight directly into electricity. Unfortunately, although these cells are becomeing more reasonably priced, they are expensive in comparison to the amount of electricity they create. They are would be unreliable as a sole source of power. In the far north, during winter months it is more difficult to use them to generate electricity since days are shorter and the sun’s rays strike the earth at greater angles. Furthermore, half of the planet is unable to generate solar power at any given time because it is not facing the sun.

Image courtesy of the National Renewable Energy Laboratory

Wind power is one of the most promising prospects for the future. It is inexpensive and fairly reliable. Wind turbines are placed high above the ground to take advantage of faster, less turbulent air flows. It is the fastest growing renewable energy source in the world and globally it accounts for more than 31,000 megawatts. In the U.S. its installed capacity is more than 6,300 megawatts. It is predicted that wind power will account for up to 6% of generated power by 2020. Wind power is absolutely pollution free and wind turbines can be placed in remote areas like mountain tops and out at sea. In addidion, they require little maintenance.

Image courtesy of Age Fotostock

Nuclear power is also an interesting alternative to fossil fuels. It is cheap, efficient, and clean. Nuclear energy is generated as fission unleashes the energy stored in the atom. Many people fear nuclear meltdowns like the one that occurred in Chernobyl, a plant in the former Soviet Union. However, these events are rare, and more people have died in fires and coal mine accidents. In 1979 the nuclear power plant at Three Mile Island underwent a partial meltdown before effective corrective action was taken. This incident was far less severe than its Soviet counterpart and today American plants meet numerous safety standards, have redundant systems, and are designed to automatically restrict reaction rates when sensors indicate an escalating reaction. Unfortunately, the disposing of nuclear waste will eventually become a problem despite safety techniques. Scientists use safe containers to store the waste, but as it accumulates it would be hard to store and keep out of the hands of dangerous people. Currently, the government has plans to sequester large quantities of nuclear waste, stored in safe containers, under Yucca Mountain in Nevada.

Image courtesy of Florida Power and Light

Hydroelectric facilities utilize water, a renewable resource, to turn turbines. They are absolutely pollution free, but can disrupt the river and ocean habitats where they are constructed. Many dams are now built with fish ladders to help salmon who migrate upstream to make their yearly mating journey. Yet, many fish can still be caught in turbines, and changes in the currents and structure of a river can severely damage the habitat. In addition, hydroelectric dams require a powerful river and suitable areas are scarce. Therefore, hydroelectric power would be unable to grow with demand.

Image courtesy of Save on Energy

Hydrogen fuels are also a promising alternative for the future. Hydrogen fuel cells, which combine hydrogen and oxygen to produce electricity, are currently used for NASA’s space vehicles because they are light weight and release a lot of energy. In fact, they release 7 times more energy than an equal amount of coal. On top of this, hydrogen can be burned purely to release only water. Hydrogen is one of the most abundant elements on the planet and the most abundant element in the universe. The only down side is that hydrogen on earth is most often trapped in water, biomass (harvested vegetation), fossil fuels, and some inorganics. There are several methods of freeing trapped hydrogen. One way is using solar power to break up the molecules in water. In this case, the fuel cell is a environmentally friendly battery for other sources of power.

The traditional sources of power are fossil fuels. They include coal, oil, and natural gas. Of them all natural gas is the cleanest while coal (which provides 51% of America's electricity) generally causes the most environmental pollution in the form of smog, soot, acid rain, and toxic metal compounds. Over the last thirty years, the coal-based electricity industry, through clean-coal technological advances such as Gasification Combined Cycle (GCC), has striven to reduce the amount of air pollutants from its plants by 31% while at the same time almost doubling its contribution to America's power grid. But remember, these resources are non-renewable so once they are depleted, we will be unable to create more of them.

Image courtesy of Tampa Electric

In the future we will have to take advantage of many different kinds of power to meet our needs. Using renewable and clean sources of power will become extremely important as the demands for power increase. Solar, wind, hydroelectric, hydrogen fuel cells, and nuclear power provide promising alternatives to fossil fuels, and with time may be able to fully meet our energy needs.