This paper is an attempt to emphasize on the importance of the non-conventional energy sources of which small hydropower generation is one. It deals with the cogeneration of hydro power along with thermal power stations. The paper describes how it will be effective to increase the overall efficiency of the thermal plant. Also it emphasizes on the appropriate and maximum utilization of both, the flow and discharge of the water used in thermal plants to generate hydro power. The paper also explores the various possibilities of harnessing energy at different locations in plant. Advantages and limitations of such an arrangement is appropriately dealt with. An introduction to the upcoming technology of the modified electronic governor control system is also dealt with.
What Is Small Hydro Power and it's Need:
Fuel prices are going up very rapidly. We need to think upon harnessing non-conventional sources of energy to our maximum. Up till now only those sites, which are large enough, where economy of scale enabled the production of energy at cost low enough to compete thermal power, fueled with low cost oil were used. But now, with advancement in developments of turbines that can use " small falls & discharges" efficiently has led to development of small hydro installation to a large extent.
As per as the bureau of the Indian standards
Depending on amount of power produced:
Overview of Small Hydro Electric Scheme with Respect to its Installation Along with Thermal Project
In thermal power plant, water is main working fluid, whether to derive steam or to cool it, excess amount of it is used, and over the whole process the flow and head of water may be utilized to harness energy . Depending upon the nature of water circuit in power plant we can have different possibilities . They are as follows:
General Advantages of SHP
Development of small-scale projects has been possible only because of upcoming technologies in field of turbo machinery, because they are capable of generating power even from very small heads . With the development of tubular, straflow and bulb turbines it is possible to utilize even smaller heads . Kaplan and Francis turbines are the other turbines that utilize low heads.
Recent Technologies: A Discussion
With the development of Modified Electronic Governor Control System the operation of SHP becomes much more simple . In such a system the gates are positioned at any desired position by pressing the required keys . There are controllers meant for runner blade control, operated only after turbine attains 80% speed . For desired opening and closing of runner blade during testing and calibration there are adequate mechanisms provided . Water level is directly maintained through changing gate positions. For plant start up all necessary auxiliaries should be started first which indication lamps on the control panel can verify . Proper synchronization between opening of gates and speed of the turbine is maintained through this modified electronic governor control system . The speed of the turbine is maintained within specified limits. Once the speed of the turbine is stabilized, the generator breaker is closed for synchronizing with the grid . Immediately after closing the breaker, some load should be taken on generator to avoid possibility of motoring operation . For planned shutdown load is reduced gradually. There are proper arrangements on the control panel itself to meet with emergencies.
Small-scale hydro plants can be set up with thermal power plants to increase the efficiency as well as the plant utilization factor.