Renewable Energy

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ABTRACT

This project paper studies the potential of hydroelectric energy as a way to effectively generate, use and store renewable energy through the clean gravitational potential energy of stored water. Nuclear and coal fired plants could do change power output to achieve demand but at extremely high maintenance cost. Nuclear plants also being a good source of continuous energy has a high chance of posing hazard to the environment. Coal and fossil fuel fired power plants on the other hand cannot be depended on because the source will diminish someday. Therefore, alternative methods have to be explored in order to find a renewable and sustainable energy for the future generations. This project paper will study the benefits of hydroelectric energy as a potential and important energy source for a sustainable future.

INTRODUCTION

1.0 Hydropower
Hydropower is a renewable energy source based on the natural water cycle. Hydropower is the most mature, reliable and cost-effective renewable power generation technology available. Hydropower schemes often have significant flexibility in their design and can be designed to meet base-load demands with relatively high capacity factors, or have higher installed capacities and a lower capacity factor, but meet a much larger share of peak demand. Hydropower is the largest renewable energy source, and it produces around 16 % of the world’s electricity and over four-fifths of the world’s renewable electricity. Currently, more than 25 countries in the world depend on hydropower for 90 % of their electricity supply (99.3 % in Norway), and 12 countries are 100 % reliant on hydro. Hydro produces the bulk of electricity in 65 countries and plays some role in more than 150 countries. Canada, China and the United States are the countries which have the largest hydropower generation capacity. Hydropower is the most flexible source of power generation available and is capable of responding to demand fluctuations in minutes, delivering base-load power and, when a reservoir is present, storing electricity over weeks, months, seasons or even years.

One key advantage of hydropower is its unrivalled “load following” capability (i.e. it can meet load fluctuations minute-by-minute). Although other plants, notably conventional thermal power plants, can respond to load fluctuations, their response times are not as fast and often are not as flexible over their full output band. In addition to grid flexibility and security services (spinning reserve), hydropower dams with large reservoir storage be used to store energy over time to meet system peaks or demand decoupled from inflows. Storage can be over days, weeks, months, seasons or even years depending on the size of the reservoir.

As a result of this flexibility, hydropower is an ideal complement to variable renewables as, when the sun shines or the wind blows, reservoir levels can be allowed to increase for a time when there is no wind or sunshine. Similarly, when large ramping up or down of supply is needed due to increases or decreases in solar or wind generation, hydro can meet these demands. Hydroelectric generating units are able to start up quickly and operate efficiently almost instantly, even when used only for one or two hours. This is in contrast to thermal plant where start-up can take several hours or more, during which time efficiency is significantly below design levels. In addition, hydropower plants can operate efficiently at partial loads, which is not the case for many thermal plants. Reservoir and pumped storage hydropower can be used to reduce the frequency of start-ups and shutdowns of conventional thermal plants and maintain a balance between supply and demand, thereby reducing the load-following burden of thermal plants.

1.1Hydropower Technologies
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3Figure??: Power Generation at a Hydroelectric Power Plant

Hydropower has been used by mankind since ancient times. The energy of falling...
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