Up to around 1980, hydropower research and development (R&D) efforts focused mainly on improving turbine efficiency, reducing cavitations, and increasing generation. Whereas older units had efficiency ratings as low as 60%, the new units have efficiency ratings of approximately 90%. The U.S. Department of Energy (DOE) also looked at new technologies for developing low-head, ultra low-head, and small hydropower projects. These technologies included the following: (more…)

Hydropower, also known as hydroelectric power, is the use of water to produce power. Harnessing water to perform work has been going on for thousands of years. The Greeks used waterwheels for grinding wheat into flour more than 2000 years ago. Besides grinding flour, the power of the water was used to saw wood and to power textile mills and manufacturing plants. This article looks briefly at how hydropower plant began, why it is considered renewable energy technology, the parts of a hydropower plant, types of turbines and when they are used, and what research and development is occurring. (more…)

The World Commission on Dams (WCD) was formed in 1998 by a joint initiative of the World Conservation Union (IUCN) and the World Bank (WB) after a historic meeting of leading dam proponents and opponents in Switzerland, with proceedings reported by Dorcey and others. The WCD was asked to discover the truth about the hydropower energy facts, hydropower energy pros and cons, cost, effect, and benefit of large dams and it functioned independently for 2 years at a cost of $10 million. The money was well spent, and at the end of that period the WCD produced a comprehensive report and numerous support documents, and then dissolved itself. The report and support documents remain on the Internet available to all, and they have changed forever the debate about dams. (more…)

Following the recent completion of three nuclear power plants, there is now some 9.6 GW of nuclear capacity in the United Kingdom. The nuclear share of electrical output, which has stood at around 13% for many years, should rise to around 20% when this capacity is in full operation. A further two reactors are currently under construction which will increase the British nuclear capacity to more than 12 GW by the late 1980s, which could bring the nuclear share of electrical output to around 25%. (more…)

More than 48% of the raw material fiber used for paper production (chemical pulp or mechanical pulp) in the United States in 2002 was recovered or reclaimed, with recovered paper contributing 37.7% and wood residues 10.6%. The total has been more or less constant, with the percentage of recovered paper increasing and that of wood residues declining recently due to their increased use in oriented strand board and composite panels. Primary fibers are a renewable, domestic resource, much of which is currently supplied by tree plantations. Short-rotation forestry can be used to further increase the productivity of these plantations. (more…)

Reductions in carbon intensity, C/E, the carbon emitted per unit of energy generated, reflect the degree to which societies decarbonize their energy sources. The long-term trend has been a shift from coal to oil to natural gas––hydrocarbons with decreasing C/H ratios emitting progressively less CO2 per joule. However, the increasing use of clean low-carbon fuels is not sustainable without somehow disposing of excess carbon because it opposes the trend in the abundance of fossil fuels, with coal resources being the most abundant followed by oil and gas. (more…)

The demand for electric energy by a community varies with the time of day and with the time of year. An electric power utility must be prepared to meet these demands. This poses an engineering problem because there is no practical method of storing electric energy on a scale that will meet the demands of a large community. To meet short-term increases in demand, electric utilities employ power generators that can be turned on and off on short notice. For example, they may use a gas turbine similar to a jet plane engine to drive a generator. Another scheme is to use a pumped storage hydroelectric system. Such a system does not rely on nature to replenish the water in a reservoir but rather uses electrically run pumps. Importantly, the system can generate electricity on short notice.

Water is forced to an elevated reservoir by a motor-driven turbine. The water in the reservoir has gravitational potential energy by virtue of the work done on it. When electricity is needed, the water is allowed to flow downward into the turbine that drives the magnetic generator motor, which now functions as an electric generator. The energy required to elevate the water is never completely recovered in the process. Nevertheless, the system is economical because the reservoir can be filled when electric energy demands and costs are low. It is also possible to have a system in which water flows from ground level to underground turboelectric perpetual generators. In this case, work has to be done to restore the water to ground level.

Taking into account losses due to evaporation of surface water exposure and energy unit conversion losses, it is estimates that approximately 70% to 85% of the electricity used to pump water into the elevated reservoir can be recovered. The technique is currently the most effective way to store large quantities of electrical energy in the form of energy operation, but the cost of capital and the presence of appropriate geography critical factors for the decision.

With energy management, well to pump storage hydroelectric systems for controlling the frequency of food production and security of reserve magnetic power generator. Thermal plants are much less able to responds in the sudden changes in electricity demand, the frequency and voltage to cause instability. Pumping stations, like other water plants can respond to changes within seconds to load with pumped storage hydroelectric system.

Coal use today is no longer evocative of dirty power plants with polluting black smoke billowing from their smokestacks. Many of these plants have been transformed through technology to operate more efficiently and with significantly lower emissions. Some fire coal with other waste materials and others produce both electric power and heat transmission. Cases of plant retrofits and their new performance statistics are documented by various institutions, including the Energy Information Administration (http:// www.eia.doe.gov) and the World Coal Institute (http://www.wci-coal.com). The following examples highlight clean coal use throughout the world: (more…)

Natural gas and oil are common source energy used to give electricity. How efficient is coal if we compare to these other source of energy? With respect to security of supply, coal has a clear advantage. The United States has about 300 million recoverable tons of coal. This amount is sufficiency to last 300 years if we are consuming coal in the same ratio that we used today. In addition, carbon is a versatile and cheap source of fuel. Coal can be used as a solid fuel or converted into a gas to replace expensive imported fuels. (more…)

High-speed maglev technology offers four main advantages: non-contact operation; low-mass vehicles (on a per seat basis, maglev vehicles weigh approximately one-third to three-quarters as much as high speed trains); high speed; and wayside system control and self-propelled vehicles (each car contains its own secondary part of a linear synchronous motors).

Non-contact operation means that vehicle traction does not depend on adhesion between contact surfaces, e.g., wheels and rails. (more…)