Alternative Energy Sources

By Hiedi Iudicello

Energy is the capacity to do work. Modern civilization has been built on man's increasingly effective harnessing of sources of energy to do work, from simple machines, steam, coal, oil, and beyond. Understanding the role of energy and human energy use is critical to an analysis of environmental issues. A number of environmental problems are attributed to our reliance on fossil fuels, yet increased use of energy is a primary signal that a country is developing a higher standard of living. elc

Non-Renewable Energy Sources

Fossil fuels, such as coal and oil, are non-renewable energy resources. Fossil fuels take millions of years to develop. Coal, oil and gas evolve from compacted plant and animal material, trapped in layers of soil millions of years ago. This buried material has been heated and pressurized in layers of soil, and eventually becomes coal, oil or gas.

In 2002, fossil fuels which are finite and nonrenewable supplied 86% of the energy consumed in the United States. Even more alarming is that the United States imports over half (62%) of its petroleum and its dependency is increasing. Since the U.S. economy is so closely tied with petroleum products and oil imports, small changes in oil prices or disruptions in oil supplies can have an enormous impact on our economy - from trade deficits, to industrial investment, to employment levels.

Coal

Coal is a complex mixture of organic chemical substances containing carbon, hydrogen and oxygen in chemical combination, together with smaller amounts of nitrogen and sulfur. This organic part of coal has associated with it various amounts of moisture and minerals. coal

Coal is the most plentiful fuel in the fossil family and it has the longest and, perhaps, the most varied history. Coal has been used for heating since the cave man. Archeologists have also found evidence that the Romans in England used it in the second and third centuries (100-200 AD).

In North American, the Hopi Indians during the 1300s in what is now the U.S. Southwest used coal for cooking, heating and to bake the pottery they made from clay. Coal was later rediscovered in the United States by explorers in 1673. However, commercial coal mines did not start operation until the 1740s in Virginia.

The Industrial Revolution played a major role in expanding the use of coal. A man named James Watt invented the steam engine which made it possible for machines to do work previously done by humans and animals. Mr. Watt used coal to make the steam to run his engine.

The burning of coal to generate electricity is a relative newcomer in the long history of this fossil fuel. It was in the 1880s when coal was first used to generate electricity for homes and factories. DOE

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Petroleum

Petroleum is a mixture of liquid hydrocarbons (chemical compounds containing only hydrogen and carbon) plus various impurities such as sulfur. Unprocessed petroleum is usually called crude oil, although it has been called mineral oil and Seneca oil, named for the Seneca Indians of Western Pennsylvania. The name petroleum is from a combination of Latin words meaning "rock oil". We refer to it here simply as oil. petroleum

Crude oil is the residue of organic waste--primarily microscopic plankton floating in seas, and also land plants--that accumulated at the bottom of oceans, lakes, and coastal areas. Over millions of years, this organic matter, rich in carbon and hydrogen atoms, was collected beneath successive levels of sediments. Pressure and underground heat "cooked" the plant matter, converting it into hydrocarbons--oil and natural gas. The tiny droplets of oil liquid migrated through small pores and fractures in the rocks until they were trapped in permeable rocks, sealed by shale rocks on top and heavier salt water at the bottom.

When oil first started flowing out of the wells in western Pennsylvania in the 1860's, desperate oil men ransacked farmhouses, barns, cellars, stores, and trash yards for any kind of barrel--molasses, beer, whiskey, cider, turpentine, sale, fish, and whatever else was handy. But as coopers began to make barrels specially for the oil trade, one standard size emerged, and that size continues to be the norm to the present. It is 42 gallons. oil

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Natural Gas

Natural gas is a highly flammable hydrocarbon gas consisting chiefly of methane (CH4). Although methane is always the chief component, it may also include other gases such as oxygen, hydrogen, nitrogen, ethane, ethylene, propane, and even some helium. gas

The history of natural gas extends to antiquity. In America it was known to the Indians, who observed it issuing from the ground in various spots, chiefly along the western side of the Appalachian Highlands. It was used for illuminating purposes in Fredonia, N.Y., as early as 1821 and the effect was so striking compared to gas made from coal that a German scientist hailed the beautiful, clear gas lights as the eighth wonder of the world. Gas associated with Pennsylvania oil was used for industrial purposes first in Pittsburgh, and its general use then spread to other industrial centers.

As a fuel, natural gas is convenient and efficient. It is used primarily for heat, in industrial, commercial and residential settings. In many homes the house and water are heated by gas, the food is cooked with it and clothes dried. It is also used to produce electricity, in many cases using gas fired turbines that are similar to jet engines. Gas has the great advantage of producing no smoke or ash on burning, although it is usually much more expensive than coal as a fuel. gas

Most of the natural gas used in the United States comes from domestic gas production. The remainder comes from imports, primarily from Canada. Domestic gas production and imported gas are generally more than enough to satisfy customer needs during the summer, allowing a portion of supplies to be placed into storage facilities for withdrawal in the winter, when the additional requirements for space heating cause total demand to exceed production and import capabilities. eia

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Nuclear Energy

Nuclear power plants are very clean and efficient to operate. However, nuclear power plants have some major environmental risks. Nuclear power plants produce radioactive gases. These gases are to be contained in the operation of the plant. If these gases are released into the air, major health risks can occur. Nuclear plants use uranium as a fuel to produce power. The mining and handling of uranium is very risky and radiation leaks can occur. The third concern of nuclear power is the permanent storage of spent radioactive fuel. This fuel is toxic for centuries, handling and disposal is an ongoing environmental issue. npp

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Renewable Energy Sources

The Role of Renewable Energy Consumption in the Nation's Energy Supply, 2003

Biomass Energy

Biomass refers to all organic matter, which contains stored carbon created through the process of photosynthesis. Virtually any organic-based material including wood products, crop residues, animal wastes, aquatic plants, landfill gas, and municipal and industrial byproducts can be utilized. Some carbon-based materials are more efficient than others, and each source has optimal applications depending on their chemical structure.

As a domestic, renewable energy source, biomass offers an alternative to conventional energy sources and provides national energy security, economic growth, and environmental benefits. Today's biomass uses include ethanol, bio-diesel, biomass power, and industrial process energy. The International Energy Association (IEA) estimates that biomass accounts for 14 percent of the world's total energy supply. The majority of this high percentage is attributed to the developing world for traditional uses. IEA projects that the global population could feasibly rely on biomass for up to half of its total energy consumption by the end of the 21st century. aei

Geothermal Power

Geothermal heat is the only renewable energy source created naturally by the earth itself. Domestically producible, reliable, renewable, and versatile, geothermal energy offers little room for objection. There is 50,000 times more energy in the upper six miles of the earth's crust than all of the global oil and natural gas reserves. While the majority of this energy is inaccessible using current technologies, harnessing even a small fraction of it would significantly contribute to the global energy mix. High temperature geothermal reserves are almost exclusively used for large-scale electricity production.

Engineers have developed four power plant designs for varying combinations of pressure and temperature: dry steam, flash-steam, binary-cycle, and hybrid systems. Currently, 0.25 percent of global electricity production comes from geothermal sources. There are 22 countries producing a total of approximately 8,000 megawatts (MW) of electricity from geothermal sources, sufficient to power 15 million homes. Electricity production in this manner is geographically limited and tends to be more costly to produce than the combustion of hydrocarbons. Aside from its higher economic costs, geothermal has many key benefits with few disadvantages. aei

Hydrogen and Fuel Cell

Hydrogen can be made by separating it from hydrocarbons by applying heat, a process known as "reforming" hydrogen. Currently, most hydrogen is made this way from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen. Some algae and bacteria, using sunlight as their energy source, even give off hydrogen under certain conditions.

Hydrogen is high in energy, yet an engine that burns pure hydrogen produces almost no pollution. NASA has used liquid hydrogen since the 1970s to propel the space shuttle and other rockets into orbit. Hydrogen fuel cells power the shuttle's electrical systems, producing a clean byproduct—pure water, which the crew drinks. You can think of a fuel cell as a battery that is constantly replenished by adding fuel to it—it never loses its charge.

Fuel cells are a promising technology for use as a source of heat and electricity for buildings, and as an electrical power source for electric vehicles. Although these applications would ideally run off pure hydrogen, in the near term they are likely to be fueled with natural gas, methanol, or even gasoline. Reforming these fuels to create hydrogen will allow the use of much of our current energy infrastructure—gas stations, natural gas pipelines, etc.—while fuel cells are phased in. hyd

Hydropower

The global community currently obtains roughly 19 percent of its electricity production from hydropower. In 2002, Canada was the world leader in hydropower production followed by Brazil, the United States, China, Russia, and Norway, in descending order. there are a number of substantial drawbacks that make the future of hydropower highly controversial. Perhaps of greatest concern, impoundment systems dramatically alter rivers' ecosystems, often with severe ecological effects on the rivers, the riparian zones, and the animal communities that depend upon these habitats. aei

Hydropower plants harness water's energy and use simple mechanics to convert that energy into electricity. Hydropower plants are actually based on a rather simple concept -- water flowing through a dam turns a turbine, which turns a generator. hsw

Oceanic Energy Sources

The world's powerful oceans cover nearly three-quarters of the earth's surface. There are four primary sources of ocean-derived energy: tidal, marine currents, wave, and oceanic thermal energy conversion (OTEC). Each source has a limited regions where it can be developed because they all uniquely tap a different aspect of the ocean. aei

Tidal energy uses hydro turbines to capture the kinetic and potential energy from the movement of the seas and the oceans, which arises from the moon's gravitational pull. Tidal energy offers a predictable source of renewable energy generation for the 21st century. tide

Solar Energy

The global population uses less energy in 27 years than the earth receives from the sun in a single day. Solar technologies are broken down into two broad categories depending on whether they utilize solar radiation directly or the heat that is derived from it. Thermal solar applications utilize the sun's radiating warmth to create electricity or heat. Fueled by energy delivered directly by the sun, solar technologies are emission-free, environmentally benign, renewable, and reliable. Currently, the global community derives three-hundredths of 1 percent of its electricity directly from the sun. Worldwide, PV sales increased at an average rate of 20 percent a year during the 1990s and then leaped to 33 percent since the turn of the millennia. aei

Photovoltaic (PV) cells are made primarily of silicon, the second most abundant element in the earth's crust, and the same semiconductor material used for computers. When the silicon is combined with one or more other materials, it exhibits unique electrical properties in the presence of sunlight. Electrons are excited by the light and move through the silicon. This is known as the photovoltaic effect and results in direct current (DC) electricity. PV modules have no moving parts, are virtually maintenance-free, and have a working life of 20 - 30 years.

PV cells were originally developed for use in space, where repair is extremely expensive, if not impossible. PV still powers nearly every satellite circling the earth because it operates reliably for long periods of time with virtually no maintenance.

PV cells use the energy from sunlight to produce electricity–the fuel is free. With no moving parts, the cells require little upkeep. These low-maintenance, cost-effective PV systems are ideal for supplying power to communications stations on mountain tops, navigational buoys at sea, or homes far from utility power lines.

Passive solar energy systems require no energy to operate and are an intrinsic part of the home design. Passive systems add little additional cost, operate with almost no supervision and require little or no maintenance. The basic elements of all passive systems are south-facing windows and internal thermal mass. Solar heating is simply sunlight entering the house that is absorbed and converted into heat energy which is later released inside the house as it cools. A passive solar home is one where the design and construction of the home itself is made to keep the house naturally warm in the winter using the sun's energy. The design should also keep the house naturally cool during the summer. pv

Wind Energy

The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity to power homes, businesses, schools, and the like.

Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator which supplies an electric current. Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water; and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor. Modern wind technology takes advantage of advances in materials, engineering, electronics, and aerodynamics. Wind turbines are often grouped together into a single wind power plant, also known as a wind farm, and generate bulk electrical power. Electricity from these turbines is fed into the local utility grid and distribute to customers just as it is with conventional power plants. wind

Some Legislation That Affects The Renewable Energy Marketplace

Legislation

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