Hydro Energy or Hydro power conversion Technology

Energy conversion is the process of changing one form of energy into another, a fundamental capability that enables modern civilization to function. It can occur in various ways, from converting the kinetic energy of wind into mechanical power through windmills to transforming solar energy into electrical energy in solar panels. This transformation is essential not just for daily usage but also for harnessing and utilizing natural resources more efficiently. In the context of rural electrification, this process plays a critical role. By converting available local energy resources into electricity, rural communities can access a stable and reliable power supply. This not only improves the quality of life but also supports economic development by powering homes, schools, businesses, and healthcare facilities. Consequently, energy conversion facilitates the broader goal of rural electrification, demonstrating the interconnection between technological innovation and societal advancement.

1. CHAPTER – 3: Hydro Power Basic Concepts (or) The general layout of Hydro Power Plant A generating station which convert potential and kinetic energy of water flow into mechanical energy and then it is converted to electrical energy is known as Hydro Power . https://energypedia.info/wiki/Hydro_Power_Basics

2. Cont.… Fig: Schematic arrangement of a Hydro Electric Plant

3. Cont.… Hydro Power system are primarily classified Based on Hydraulic characteristics are: Run-Of-River plant ( diversion plant ) Storage plant (impoundment plant ) Pumped Storage plant

4. Fig: Diversion (Run-of-River) Hydropower

5. Fig: Storage plant (impoundment) Hydropower

6. Fig: Pumped storage Hydropower

7. Cont.… Secondary classification of hydro power plant based on design head are: High Head ( 300m and above ) Medium Head (30m to 300m) Low Head (less than 30m) Power is proportional to head and flow rate of the water. Head (the vertical distance between the intake and turbine) Flow (how much water comes down the stream)

8. Cont.… The main components of the hydro station are: Reservoir Dam Spill ways Intake Fore bay Penstock Surge tank Prime mover Power house

9. Cont.… Reservoir The main function of the reservoir is to store water during rainy season and use it during dry season. Dam A dam is a barrier constructed in the path of the river. It develops a reservoir which has capacity store water.

10. Cont.… Spill ways It acts as a safety valve for a dam. It is helpful to release a water when the water exceeds the maximum margin level of the dam in order to protect the dam. Intake It allows the water to flow into the penstock under controlled conditions.

11. Cont.… Fore bay It is an enlarged body of water just above the intake. It is used as a regulating reservoir. Penstock The pipe between surge tank and turbine is known as penstock . It is made up of steel through reinforced concrete. It supplies water from the fore bay to the turbine.  

12. Cont.… Prime mover Hydro turbine is a prime mover coupled to the hydro generator which converts the kinetic energy of water flow to mechanical energy. The water turbines are two types. They are Impulse turbine and Reaction turbine (Francis and Kaplan turbine).

13. Mention The merits and demerits of hydro power plant Merits : Hydro power plant requires no fuel since water is used for generation of electrical energy. It is quite neat & clean (since no smoke and ash is produced). Running cost is low.

14. Cont.… It is simple in construction and requires less maintenance. It does not require long starting time like steam power plant. In addition to the generation, it also helps in irrigation and controlling floods.

15. Cont.… Demerits High capital cost (due to construction of dam). Uncertainty about the availability of water throughout the year. Skilled persons are required to build the plant It requires high cost of transmission lines (as the plant is located in hilly areas which are quite away from the consumers).

16. How to choose the site of hydro power plant? (Or) Site Selection The site of hydro power plant should have the following: Availability of water Huge amount of water is required for hydro power generation; therefore hydro power plant should be located at the bank of the river or near the canal to ensure the continuous supply of water. Storage of water The site should provide adequate facilities for erecting a dam and storage of water .

17. Cont.. Cost and type of land Cost should be reasonable since it requires more land when compared to the nuclear plant. The bearing capacity of the land should be adequate so that heavy equipment could be installed. Transportation facilities The site should be accessible by road or railways so that necessary equipment's and machinery could be easily transported .

18. Types Of Hydropower Turbines There are two main types of hydro turbines: Impulse and Reaction . The type of hydropower turbine selected for a project is based on the height of standing water-referred to as " head“-and the flow, or volume of water, at the site. Other deciding factors include how the efficiency and cost of the turbine is.

19. Cont... Impulse Turbine 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. Example: Pelton turbine.

20. Cont... Reaction Turbine A reaction turbine develops power from the combined action of pressure and moving water. The runner is placed directly in the water stream flowing over the blades rather than striking each individually. Reaction turbines are generally used for sites with lower head and higher flows than compared with the impulse turbines. Example : Propeller Turbine, Kaplan Turbine.

21. Cont... Figure: Reaction Vs Impulse Hydraulic Turbines

22. Small Scale Hydro Power for the Home Depending upon the physical size, head height and electrical power generating capacity, small hydroelectric schemes can be categorized into Small Mini and Micro scale h ydro schemes.

23. Cont... Small Scale Hydro Power:   It is a scheme that generates electrical power of between 100kW and 1MW (mega-watts) feeding this generated power directly into the utility grid or as part of a large stand alone scheme powering more than one household.

24. Cont... Mini Scale Hydro Power: is a scheme that generates power between 5kW and 100 kW , feeding it directly into the utility grid or as part of a battery charging or AC powered stand alone system . Micro Scale Hydro Power:   It is usually the classification given to a small home made r un-of-river type scheme that use DC generators to produce electrical power between a few hundred watts up to 5kW as part of a battery charging stand alone system .

25. Cont... Small scale hydro power systems, as well as  Mini Hydro Systems  or  Micro Hydro Systems , can be designed using impulse type hydro turbines. The generation potential of a particular site will depend upon the amount of flow of the water , the available head which in turn is dependent upon the site conditions and location and the rainfall characteristics of the site.

26. Cont... If there is sufficient head and flow, small hydro power plants can be driven directly from a river or stream, called a “run-of-river” system built into or at the side of a river or a stream without the need to dam, divert or change the flow of water in any way. Making them the cheapest solution for generating power.

27. How Much Power can we Extract from the Water Water turbines are great for any small scale hydro power scheme as they extract the kinetic energy from the moving water and convert this energy into mechanical energy which drives an electrical generator producing a power output .

28. Cont... In order to determine the power potential of the water flowing in a river or stream, it is necessary to determine both the flow rate of the water passing a point in a given time and the vertical head height through which the water needs to fall. The theoretical power within the water can be calculated as follows.

29. Cont... Where: P = power in kilowatts ( kW) g = gravitational acceleration (9.81 m / s 2 ) η = turbo-generator efficiency (%) Q = quantity of water flowing ( m 3 /sec) H n = effective head ( m ) ρ = density of water (1000 Kg/m3 ).

30. Cont... Problem - 1: A small stream drops 20 meters down the side of a mountain producing a water flow rate of 500 liters per minute past a fixed point. How much power could a small scale hydro power plant generate in kilo-watts, if the type of water turbine used has a maximum efficiency, (η) of 85 %. Solution: The data given: Head = 20m, Flow rate = 500 Lts /min, Efficiency = 0.85 and Gravity = 9.81 m/s 2 . But first we must convert the water flow rate of 500 litres per minute into m 3 /sec.

31. Cont... 1,000 liters is equal to 1m 3 , so 500 liters is equal to 0.5m 3 . One minute is equal to 60 seconds, then a flow rate of 0.5m 3  per minute is equal to 0.00833 m 3  per second. Considering the density of water, Note: Now  1.4 kW  may not seem much, but this is equivalent to over 12,000 KWh (1.4 x 24 x 365) of free hydro electricity annually. P ( kW) = 9.81 x 0.00833 x 20 x 0.85 P ( kW) = 1 .389 = 1.4

32. Cont... Problem 2: A hydropower station has a gross head of 8.2 meter. Head loss in water conductor system is 0.5 meters. Optimum discharge in cumecs is 267 cubic meter per second. For general estimation purposes , η is normally taken as 0.85 calculate the power and annual energy of the plant. Solution : P (kW) = 9.81 x 267 x 7.7 x 0.85 P = 1 7.143 MW Energy generation E = average power x 24 x 365 in (kWh) units E= 1 7.143 *24*365 = 150.174 T Wh

33. Components of a Small Scale Hydro Scheme A typical  small scale hydro power  scheme, needs a stream , an intake system to divert the water, a canal or channel called a penstock to carry the diverted water, a water turbine or water wheel to convert the waters kinetic energy into a rotational mechanical energy and an electrical generator to convert this rotational energy from the wheel into electricity.

34. Cont... Figure: A typical  small scale hydro power  scheme

35. Small Scale Hydro Generators As well as the civil works , one of the hardest parts of designing a small, mini or micro hydro system for electricity production is choosing the correct generator to partner the water turbine . There are many of-the-shelf electrical machines available, and all have there advantages and disadvantages but permanent magnet alternators are by far the most popular choice in successful small scale hydro power designs.

36. Cont... Small Hydro AC Generators   These are used for grid connected schemes and can be single-phase or three-phase machines. AC hydro generators are connected permanently to the wiring system of the house, supplying the loads directly. The system should include a power conditioner to ensure that the output to the utility grid is always steady and at the correct voltage and frequency regardless of the speed of the turbine.

37.   THANK YOU