 Hello everyone, my name is Saurabh Deshmukh, working as an assistant professor in mechanical engineering department, Walshan Institute of Technology, in earlier video we have seen some forms and characteristics of renewable energy sources, we are going to continue with the same topic in this video, learning outcomes. At the end of this session, the learner will able to explain various forms of renewable energy sources along with their characteristics. Content In this video, we are going to see the tidal energy, geothermal energy and biomass energy, the tidal energy. Tidal energy is renewable energy powered by the natural rise and fall of ocean tides. The kinetic energy of tide or waves is converted into electric energy. During 20th century, engineers developed ways to use tidal movement to generate electricity in areas where there is significant tidal rain. Depending upon the gravitational pull of the moon and the sun, the nymphs tide and spring tide occurs. So it is easy to predict when the tides are going to form. The tidal energy production is still in infancy. The amount of power produced is so far has been small. There are very few commercial sized tidal power plants operating in the world. The first figure shows the nymph tide that is low tide and second figure shows the spring tide that is high tide. These two figures shows the generation of electricity with the help of tide. The tidal barrages are long concrete structure usually built across the coastlines. The barrages have tunnels along them containing turbines which are used when the water on the one side flows through the barrages which cause the rotation of the turbines. These dams like structures are said to have lifespan around 100 years. Tidal energy is zero emission method or the carbon footprints left behind while the producing electricity is zero. We can easily control the flood with the help of tidal barrages to protect the coastal area. Currently, it is expensive to construct a tidal power plant. The cost to build tidal power plant of 1 megawatt energy ranges from 30 to 60 crores. Powerful tides only happen normally 10 hours per day so we need to increase the storage capacity of tidal energy power plant. According to the National Energy Board of Canada, South Korea has highest tidal energy capacity of 511 megawatt. In India, the tidal energy is in still research and development phase and has not been implemented on commercial scale. These are the some characteristics of tidal energy power plant. The tides and waves are easy to predict because they are dependent on the gravitational pull by the moon and the sun. The tidal energy is still under the development and it also requires high initial cost. As we can generate tidal energy around 10 hours per day, so I want you guys to think the different ways to increase the storage capacity of tidal energy plant. Just take your time and note down different ways to increase the storage capacity of tidal energy plant. Can we increase the time which is right now 10 hours per day to increase the electricity to up to 14-15 hours per day? The next renewable energy source is geothermal energy. The geothermal word comes from the Greek word geo that is earth and thermi that is heat. As heat is continuously produced in the earth core and easily available, this is renewable energy. Climate reservoirs can reach temperature of 700 Fahrenheit or 360 degree Celsius which is almost 3 times of the boiling point of the water. With the help of this geothermal energy, we can run the turbines to produce the electricity. The figure shows the typical layout of the geothermal power plant. Like all other conventional thermal power plants, the geothermal power plant uses the heat source to expand the liquid to vapor or steam. This high pressure vapor or steam is used mechanically to turn the turbine generator. At the geothermal power plant, fuel is geothermal water heated naturally inside the earth. So we don't require burning of any fuel. With the help of hot steam available in the crust of earth, the turbines rotated which are connected to the generators to produce the electricity. The condensed steam or water is again injected in the crust with the help of injection well as shown in figure. The estimated potential geothermal energy in India is about 10,000 megawatt. The figure shows the hotspot known for the geothermal regions. You can see the red marks along the coastal area of Australia, New Zealand, Japan, west coast of America, Chile, Mexico. This region is known as the ring of fire. The next renewable energy source is biomass energy. The term biomass encompasses a large variety of materials including wood from various sources, agriculture residues, animal and human waste also. These biomass are burned to generate the heat to produce the steam to run the turbines. As we can start and stop the burning of biomass to produce the heat, it is controllable renewable energy source and available when needed. The air dried wood which is the most commonly used biomass contains around 15 mega joule per kg energy. But if it is over dried before it burned, it boosted around 18 mega joule per kg. This diagram shows the typical layout of direct combustion or steam turbine system for biomass energy. The biomass is stored, then it is proceeded to the burning process. With the help of the energy produced or heat produced by the burning of biomass, we heat the water to convert it into the high pressure steam which is then provided to the turbine to produce the electricity. Then the condensed vapor is again used and we can heat that condensed steam to again provide it to the turbines. This chart shows the renewable energy generation data. The energy generation by the various means of renewable energy sources. We can observe the energy produced by the renewable hydropower contributes around 50 to 60 percent of the total energy produced by the renewable energy sources, followed by offshore wind, solar photovoltaic, solar thermal, solid biofuel and biogas. These are the references. Thank you.