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…)

Hydraulic turbines have two main classifications: impulse and reaction. The impulse turbine generally uses the velocity of the water to move the runner and discharges to atmospheric pressure. The water stream hits each bucket on the runner. There is no suction on the down side of the turbine, and the water flows out the bottom of the turbine housing after hitting the runner. An impulse turbine is generally suitable for high-head, low-flow applications. (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 winners in hydropower and other large dam projects are those who gain electricity, domestic water supplies, sanitation, drought relief, sustainable irrigation, flood control, improved water transport, industrial and employment opportunities, food security, better roads, telecommunications, and other benefits. As well, other economic multipliers may arise and whole regions may flourish. This is an impressive list and is the very basis of modernization and liberation from the drudgery of traditional low technology rural life. Electricity, radio, and domestic water supplies completely transform the lives of those who gain these goods, and better health and education are the most obvious outcomes. (more…)

The water levels of most of the world’s rivers fluctuate with seasonal rains, melting snows, or droughts, and in the arid zones there are flash floods. It makes sense to capture and store the abundant waters and later release it during the low flow periods or use it for power. So dams have been built for the purposes of irrigation, municipal water supply, and hydroelectricity generation. Flood control and transportation benefits are also important. Cities are growing all over the developing world, and they require water supplies and reservoirs. Since the beginning of the 20th century, hydropower energy has steadily increased and it now supplies 19% of worldwide electricity. (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…)

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.

Many small-scale energy systems require effective miniaturized pumps and expanders. These devices are responsible for conveying a working fluid through various components to execute a cycle that may result in power production, heat pumping, or refrigeration. As an example, a pump is required for pressurizing the working fluid in Rankine power cycles. Miniaturized pumps could also cycle a heat transfer fluid through a cooling loop for heat rejection purposes. On the other hand, expanders are necessary for any cycle employing a working fluid to generate power. Specific examples include microturbines, miniaturized piston-based machines, and roots-type expanders. (more…)

Water power sources is an interesting source of energy. It is available freely in nature. The constant flow of water can guarantee the availability of energy. Water power take it sources of energy from the motion of water. The motion of water is happening in river, sea and water fall. This movement can be derived from two resources:

1. Flows of water streams, this is attracted by earth gravity force
2. Tides which are the rise and fall of sea level by moon and sun gravity force (more…)