A COMPREHENSIVE STUDY OF CANAL BASED MINI HYDRO POWER PLANTS

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1 A COMPREHENSIVE STUDY OF CANAL BASED MINI HYDRO POWER PLANTS 1 RAJESHWARI.S JAMAGOUD, 2 RAVINDRA G.PATIL 1 Student M.Tech(PES), 2 Associate Professor PG-Power and Energy Systems, Department of Electrical and Electronics Engineering, Basaveshwar Engineering College (Autonomous), Bagalkot , Karnataka, India Abstract- Large potential of energy still remains untapped in irrigation canals in central and southern parts of India and other countries. This energy can be utilised to augment the gap between demand and supply. The advantages of canal based mini hydro power plants are that being in a plain area, they are near to the load centres, easily accessible and they do not encounter the problems of rehabilitation of people and environmental problems associated with the large hydro power plants. Hydro electric power plants generate from few KW to thousands of MW. They are classified as Mini hydro power plants for the generating capacity one to three MW. This paper presents the comprehensive study of potential sites namely shahapur schemes in yadgir region of Karnataka state in India. The work is carried out for evaluating canal based mini hydro power plants (MHPP) generation availability that can be applied to generation systems reliability and to generation planning studies. The amount of electricity that can be generated at these sites depends on canal discharge, head, and gird availability. While calculating the capacity of power plant to be installed at these sites, it is assumed that there will be water reservation for irrigation and other application also. The expected value of the annual power generation of the canal based MHPP. The duration curve is then plotted. Keywords- average power; generation loss; Seasonal variation in discharge; seasonal variation in power I. INTRODUCTION The first use of moving water to produce electricity was a waterwheel on the Fox River in Wisconsin in Hydropower continued to play a major role in the expansion of electrical service early in this century around the world [1]. Mini hydro power plant has a capacity of up to 3 MW. Hydropower is one of the most important natural resources of renewable energy. it is required to give more emphasis on development of renewable sources of energy and adoption of energy efficient and clean technologies to the extent possible. Hydro power represents non-consumptive, non-radioactive and non-polluting use of water resources towards inflation free energy development with mature technology and spectacular operational flexibility. Worldwide total hydropower capacity in operation is 807 GW with annual generation of 3030 TWh/year. Presently, hydropower is contributing more than 50 percent of electricity supply in about 60 countries. Hydropower, large and small has been important source of energy in all European countries possessing water potentials [5]. India started with total installed capacity of 136 2MW AT 1500 sites and per capita consumption of 14 KWh in 1947 when it got its independence. The hydropower capacity increased from 508 MW in 1947 to MW in In recent years, Indian economy has been growing at a rate exceeding 6.5 % and expected to be maintained in coming years, thus demand for energy will increase accordingly. The present installed capacity of power generation in India is MW; out of which hydropower is 26%, thermal is 66%, renewable is 5% and nuclear is 3%. The country is still short of power. The shortage is 7% on an average and 11.2%at the time of peaking [5]. The current concern on the global environment has imposed a new restrain on the production of electricity and the emphasis is put on the development of environment friendly energies to promote the sustainable social development. It is in these circumstances, mini hydro power is drawing more attention. The possibilities of mini hydro schemes in the plains usually occur on the canal falls that would be existing in the irrigation canal system. Such schemes are also very much amenable for connection to nearby grid. The canal based schemes utilizes power potential available due to flowing water and head at canal falls. The amount of electricity that can be generated at a hydro power plant is determined by two factors: head and flow. Head is how far the water drops. It is the distance from the highest level of the demand water to the point where it goes through the power-production turbine. Flow is how much water moves through the system. Generally, a high-head plant needs less water flow than a low head plant to produce the same amount of electricity [4]. In this paper, the concept of utilizing the canal water-flow and available head to generate hydro power is put forth. After generation of power, water would be taken back to canal through tail-race and water would continue to do irrigation of agriculture land as planned earlier. It does not disturb the main activity of irrigation but in addition. It is helping in generation of power. This concept is useful to utilise 73

2 untapped renewable energy in today s power scarcity world. Hydrological data of the canal should be available with satisfactory water-flow. Depending hydrological data available, calculation of different parameters like the water-head and discharge, maximum and minimum power that could be generated is also studied [3]. II. BENEFIT AND ULTIMATE OBJECTIVES OF THE CANAL BASED MINI HYDRO PROJECT The interest in small/mini/micro hydro project has grown up in India for reasons like: Canal based mini hydro power plants do not encounter the problems of population displacement and environment problems associated with the large hydro power plants. Canal based mini hydro power plants are planned close to load centres and provide electricity reliable and cost effectively and avoiding transmission and distribution losses. Moderate investment for providing electricity Can be set up in remote hilly area to provide electricity to that area. Attractive for small private entrepreneurs because of less capital outlay. Environment friendly so helps in maintaining ecological balance. Improves economic conditions of the areas where the projects are set up. III. POLICY AND INCENTIVES FOR DEVELOPMENT OF SMALL/MINI/MICRO HYDRO POWER PLANT In India the importance of renewable energy development was recognized as early as in At central government level, Department of Non-Conventional Energy was established in 1982 which was subsequently upgraded to Ministry of Non-conventional Energy Sources and renamed as Ministry of New and Renewable Energy since October Till 1991, the electricity generation and distribution in India was in government sector only, after that it was opened to private sector also for development. The present share of private sector in hydropower generation is 3.3% and 12 % in all forms of energy generation. India is a union of states and there is a division of executive and legislative powers between the Indian Union (Central government) and the states. Hydropower is a state subject and interstate rivers are dealt by central government. Hence for hydropower development both the central and state governments are involved. With the beginning of 21st century, commercialization in the SHP sector took new dimensions. Private entrepreneurs found attractive business opportunities in small hydro. State governments started formulation/ refinement of policies to make hydropower development, entrepreneurs friendly. The procedure of allotment of sites was stream lined and made more transparent. The government of India announced new electricity act in 2003, national electricity policy in 2005 and tariff policy in 2006 to create a conductive atmosphere for investments in the power sector. The electricity act 2003 has specific provisions for the promotion of renewable energy including small hydropower. It has been made mandatory that every state would specify a percentage of electricity to be purchased from renewable. Small hydropower projects are now governed by these policies and tariff is decided by state electricity regulatory commissions as per tariff policy. A package of incentives includes customs duty concession, income tax exemption on SHP projects for power generation for 10 years. Some states of India are also giving sales tax and electricity tax exemption on the electricity generated by SHP projects. Sixteen states have framed policies on SHP. Main features of these policies are given below [5]: Private sector participation in hydropower including SHP has been permitted. Wheeling of power has been permitted. Power banking is permitted Buy back of electricity per unit is generally at the rate of Rs. 2.50, although it varies in different states. Many states provide for annual escalation of rates. Third party sale of power is allowed in many states even outside the state. States provide other concessions such as lease of land, exemption from electricity duty and entry tax on power generation equipment. Some states do not levy any water charges while some levy it as a percentage of electricity tariffs. All states have appointed nodal agencies to facilitate participation of developers. Some states have prescribed the minimum quantum of power produced from renewable sources that the state distribution licensee must purchase. Ministry of New and Renewable Energy in India has classified the hydro power plants (under Renewable Energy generation) as: Micro-hydro: up to 100 KW Mini-hydro: 101 KW KW Small-hydro: 3001 KW KW Below 100 KW capacity would come under Pico Hydro and above KW capacity would be under Large Hydro power projects. IV. DATA COLLECTION AND ANALYSIS The Bhorukha Power Corporation limited was installed a string of canal based mini hydro power plants on Shahpur branch canal of Tungabhadra project in Karnataka State of India. There are five mini hydro schemes each has power generation capacity of 74

3 1.3 MW. The total installed capacity of power generation at shahapur schemes is more compared to the other canal based hydro power plants. Hence this project is limited to these particular hydro schemes. The required data has to be obtained from each of the selected hydro scheme for period of ten month. The necessary data to be observed are the generation, the grid availability, the head and flow availability of the particular hydro scheme being selected for the analysis all the obtained data should be sorted out month wise with respect to actual generation, breakdown time and then have to be analysed to know the performance of the machine. necessary action have to be taken after knowing the factors which effect the power generation so that better control and monitoring can be done for the efficient power generation. Table.1. flow rate (Discharge) of five schemes in cusec The hydrological and generation data for the five potential sites in Shahapur region of Karnataka State, India was collected. From the analysis of data, the possible capacity of power plant to be installed at these five sites is calculated. While calculating the capacity of power plant to be installed at these sites, there is water reservation for irrigation and other application also. The amount of power generated in these sites depends on canal discharge, head, gird availability and machine availability. But after closely observing the data available, it is found that even for the shahapur Brach canal the discharge is very less for summer and it is off-course very high for rainy days. For Five potential sites, the monthly average value of discharge is calculated. This deviation shows how power generation can change in a month. Figure 1 shows the month wise average discharge for the year for five sites. To calculate month wise discharge, daily average discharge has taken because discharge variation in canal is more and very frequent as compared to river and other streams. These figures show the canal discharge is more during the months September to January and scheme-1 has more discharge rate compared to others. Table.2 gives the plant load factor and plant availability factor of potential sites during the year The plant load factor is defined as the Total power generation of the day divided by the product of Individual scheme capacity and 24 hours. Table.2 PLF for Shahapur MHP Scheme 1 to 5 Fig. 1 Discharge rate in cusecs for scheme 1, 2, 3, 4 & 5 Table.1 shows the month wise average discharge for shahapur five schemes. The amount of electricity that can be generated at a hydro plant is determined by two factors: head and flow. Head variation in canal based hydro power plant is very less but discharge variation is more compared to other hydro power plants. So that amount of power generated by these schemes dependable on canal discharge. The plant load factor of canal based mini hydro power plant is less compared to other type of hydro power 75

4 plant due to loss of generation caused by different types of outages. In shahapur canal based mini hydro power plants generation loss mainly occurs due to different types of outages. Outage duration refers to a period of time that a system fails to provide or perform its primary function. Reliability, availability, recovery and unavailability are related concepts. The unavailability is the proportion of a time span that a system is unavailable. This is usually a result of the system failing to function because of an unplanned event or because routine maintenance or planned event. There are two types of outages. Planned Outages: A planned outage is a situation where an item of an electrical plant or a circuit has to be temporarily taken out of service for repair or to allow network alterations. The planed outage is outage taken intentionally to carry out civil, electrical, mechanical works. There three types of planned outages Planned Outage Civil (POC) Planned Outage Electrical (POE) Planned Outage Mechanical (POM) Forced or Unplanned outages: An unplanned outage is a result of the loss of a section of the power network due to a fault. There are several major categories of faults which may occur without prior indication. Some common types are equipment failure, cable faults, damage by third parties or severe climatic conditions adversely affecting the networks (such as a lightning strike). Fig.2 Generation Loss of Shahapur Scheme-1 in KWH Fig.3 Generation Loss of Shahapur Scheme-5 in KWh Looking at fig.2 and fig.3 Forced outage external KPTCL in both scheme is more compared to all outages. This outage occurs due to 33KV Supply failure, 33KV Conductor Snap, 33KV Insulator failure and Maintenance works by KPTCL. Once the average discharge and loss of generation is obtained, then possible power generation isfound out. It is checked with capacities found out considering discharge and grid availability. These canal based hydro schemes are operated over period of ten month in a year. In these schemes the amount of power generation depends on discharge, head, grid availability and machine availability. The Forced outage generally occurs when the maintenance activity is carried out by KPTCL or faults on line or due to machinery breakdown and low canal discharge or canal closure. There are six types of forced outages. Forced Outage Internal Civil (FOIC) Forced Outage Internal Electrical (FOIE) Forced outage Internal Mechanical (FOIM) Forced outage Internal Others (FOIO) Forced Outage External KPTCL (FOEK) Forced Outage External Irrigation (FOEI) Forced outage external KPTCL occurs due to 33KV Supply failure, 33KV Conductor Snap, 33KV Insulator failure and Maintenance works by KPTCL. Forced outage external irrigation occurs due to canal closure and low canal discharge. Figure 2 & 3 shows the loss of generation in scheme1 & 5, caused by different types of outages. Fig.4 Power Generation In million KWh from 1997 to 2014 The figure gives the average power generation possible at five different sites for the period of 17 years. From the above power generation curve plotted it is observed that, In the year 2002 and 2003 all Schemes are generated more power compared to other years. Shahapur Scheme-1 has high plant load capacity and more discharge rate therefore this scheme is generated more power compared others. 76

5 value. But in these schemes no power generation is possible for the month of April to June because at these months canal water is not present. REFERENCES Fig.5 power generation in KWh during the year CONCLUSION The proposed hydro power projects should be viable technically as well as financially. The basic concept given in this work could be further utilized such that after power generation through turbine, water could be taken back to canal through tai-race and could be used for irrigation purpose. This concept is unique and could be very useful now-a-days as to utilize un-tapped renewable energy. The installed capacity of shahapur scheme 1 to 4 is 1300 KW. Through August to February all five schemes can more generate power. In month of July and March these schemes are generated at derated [1] Mrs. S. P. Adhau, Dr. R. M. Moharil, Mr. P. G.Adhau Estimation of Micro Hydro Power plant Capacity from Potential Sites 2012 IEEE International Conference on Power Electronics, Drives and Energy Systems December16-19, 2012, Bengaluru, India. [2] Mohibullah, Mohd. Amran Mohd. Radzi and Mohd Iqbal Abdul Hakim Basic Design Aspects of Micro Hydro Power Plant and Its Potential Development in Malaysia. National Proceedings of Power and Energy Conference 2004,PECON November 2004 IEEE [3] Mrs. S. P. Adhau, Dr. R. M. Moharil, Mr. P. G.Adhau Mini-Hydro Power Generation on Existing Irrigation Projects: Case Study of Indian Sites Renewable and Sustainable Energy Reviews 16 (2012) [4] Mrs. S. P. Adhau, Dr. R. M. Moharil, Mr. P. G.Adhau Design of Mini Hydro Power plant on Small Weir: Need based Technology for Rural Electrification /12/$ IEEE. [5] Singal S.K, Saini R.P and Raghuvanshi C.S Cost Optimisation Based on Electro-Mechanical Equipment of Canal Based Low Head Small Hydropower Scheme Open Renewable Energy Journal, 2008, 1,