Introduction to RE Sources. 22.7.20.pptx

renewable energy system

1. UNIT I RENEWABLE ENERGY (RE) SOURCES  Environmental consequences of fossil fuel use, Importance of renewable sources of energy Sustainable Design and development Types of RE sources Limitations of RE sources Present Indian and international energy scenario of conventional and RE sources.

2. RENEWABLE ENERGY Renewable energies are sources of clean, inexhaustible and increasingly competitive energy. They differ from fossil fuels principally in their diversity, abundance and potential for use anywhere on the planet, but above all in that they produce neither greenhouse gases – which cause climate change – nor polluting emissions.

3. Fossil fuels Fossil fuel , any of a class of  hydrocarbon -containing materials of biological origin occurring within Earth’s crust that can be used as a source of  energy . Fossil fuels include  coal ,  petroleum ,  natural gas ,  oil ,  bitumens ,  tar sands , and  heavy oils . All contain  carbon  and were formed as a result of geologic processes acting on the remains of organic matter produced by  photosynthesis .

4. Fossil fuels All  fossil  fuels can be burned in  air  or with  oxygen  derived from air to provide  heat . This heat may be employed directly, as in the case of home furnaces, or used to produce  steam  to drive generators that can supply  electricity . In still other cases for example, gas  turbines  used in  jet  aircraft—the heat yielded by burning a fossil fuel serves to increase both the  pressure  and the  temperature  of the  combustion  products to furnish motive  power .

5. Coal

6. What is the future of fossil fuels? Most of the electricity generated in the U.S. has traditionally come from fossil fuels like coal, petroleum and natural gas. For generations we have used these fuels to create the energy that powers our homes and businesses, but this cannot continue indefinitely.   Fossil fuels are not renewable, and the remaining stock is continuously running down, and will eventually be completely depleted. The problem though, is not just the issue of supply. It is now understood that burning fossil fuels has had a damaging effect on the environment. The longer we use them, the worse the damage.

7. The industrial revolution and its impact If we turn the clock back only a few hundred years, we find people burning wood to warm their homes and cook their food. Towns and village located near rivers could grind their grain using water mills and then use wood fires to produce bread. The impact of all of this on our planet was relatively small, but with the arrival of the industrial revolution this all changed. Fossil fuels such as coal, and then oil and natural gas were dug from the earth and burned to power the factories springing up everywhere. As industry grew, the air above the populated industrial cities became heavily polluted with clouds of smoke. Cities like London were often blanketed with fog so thick, that people lost their way walking through the streets, coughing and with eyes burning!

8. What causes the Carbon footprint? Fossil fuels were formed million years ago from the plants and living organisms that populated the ancient world. All living matter is made up largely of the element carbon and the fossils that formed retained the carbon that was present in these organisms when they died. Carbon burns, and as a result it is a source of energy. The problem is that when we burn coal, oil, and natural gas for fuel, this carbon pours out into the atmosphere. There its combines with oxygen to form the gas carbon dioxide (CO2).

9. Carbon dioxide is a ‘greenhouse’ gas, therefore it has the effect of trapping the sun’s energy as it enters the earth’s atmosphere, generating a warming greenhouse effect. Greenhouse gases like carbon dioxide thus contribute to causing a global warming effect that scientists are able to quantify. Our dependence on burning fossil fuels, thereby releasing the carbon stored in them, means that we’ve been continuously increasing the carbon ‘footprint’.

10. Environmental consequences of fossil fuel use These impacts include global warming, air quality deterioration, oil spills, and acid rain. Among the gases emitted when fossil fuels are burned, one of the most significant is carbon dioxide, a gas that traps heat in the earth's atmosphere. Fossil fuels are also implicated in increased levels of atmospheric methane and nitrous oxide, although they are not the major source of these gases. Several important pollutants are produced by fossil fuel combustion: carbon monoxide, nitrogen oxides, sulfur oxides, and hydrocarbons. In addition, total suspended particulates contribute to air pollution, and nitrogen oxides and hydrocarbons can combine in the atmosphere to form tropospheric ozone, the major constituent of smog. Carbon monoxide is a gas formed as a by-product during the incomplete combustion of all fossil fuels. 

11. Environmental consequences of fossil fuel use

12. Environmental consequences of fossil fuel use

13. Environmental consequences of fossil fuel use Production, transportation, and use of oil can cause water pollution. Oil spills, for example, leave waterways and their surrounding shores uninhabitable for some time. Such spills often result in the loss of plant and animal life. Coal mining also contributes to water pollution. Coal contains pyrite, a sulfur compound; as water washes through mines, this compound forms a dilute acid, which is then washed into nearby rivers and streams.

14. During the electricity-generation process, burning fossil fuels produce heat energy, some of which is used to generate electricity. Because the process is inefficient, much of the heat is released to the atmosphere or to water that is used as a coolant. Heated water, once returned to rivers or lakes, can upset the aquatic ecosystem.

15. The burning of all carbon-containing fuels inevitably produces huge quantities of carbon dioxide. With efficient combustion, all of the carbon in the fuel is converted to carbon dioxide. Carbon dioxide is a desired product of fuel combustion. It is also a normal constituent of air, at an average concentration of 0.0315% (315 parts per million). So it is not usually considered to be a primary air pollutant.

16. What will the future bring? Scientists say that the effects of warmer temperatures are resulting in: disappearing Arctic ice melting glaciers dying coral reefs. longer periods of drought in some regions more frequent forest fires an increase in the number, duration and intensity of tropical storms the occurrence of more extreme weather events rising sea levels, and ecosystem changes

17. ACID RAIN

18. ACID RAIN The term acid rain was coined in 1852 by Scottish chemist  Robert Angus Smith , according to the Royal Society of Chemistry, which calls him the "father of acid rain." Smith decided on the term while examining rainwater chemistry near industrial cities in England and Scotland.  Sulfur  dioxide (SO 2 ) and nitrogen oxides (NOx) released into the air by fossil-fuel power plants, vehicles and oil refineries are the biggest cause of acid rain today. Two thirds of sulfur dioxide and one fourth of nitrogen oxide found in the atmosphere come from electric power generators. 

19. ACID RAIN A chemical reaction happens when sulfur dioxide and nitrogen oxides mix with water, oxygen and other chemicals in the air. They then become sulfuric and nitric acids that mix with precipitation and fall to the ground. Precipitation is considered acidic when its pH level is about 5.2 or below, according to  Encyclopedia Britannica . The normal pH of rain is around 5.6.

20. Effects of Acid Rain Acid rain affects nearly everything. Plants, soil, trees, buildings and even statues can be transformed by the precipitation. Acid rain has been found to be very hard on trees. It weakens them by washing away the protective film on leaves, and it stunts growth.  Acid rain can also change the composition of soil and bodies of water, making them uninhabitable for local animals and plants. For example, healthy lakes have a pH of 6.5 or higher. As acid rain raises the level of acidity, fish tend to die off. Most fish species can't survive a water pH of below 5. When the pH becomes a 4, the lake is considered dead, according to  National Atmospheric Deposition Program .

21. Solutions There are several solutions to stopping manmade acid rain. Regulating the emissions coming from vehicles and buildings is an important step. This can be done by restricting the use of fossil fuels and focusing on more sustainable energy sources such as solar and wind power.

22. Also, each person can do their part by reducing their vehicle use. Using public transportation, walking, riding a bike or carpooling is a good start, according to the EPA. People can also reduce their use of electricity, which is widely created with fossil fuels, or switch to a solar plan. Many electricity companies offer solar packages to their customers that require no installation and low costs. 

23. Is there a solution to the pollution caused by fossil fuels? The answer lies in utilizing non-polluting and renewable energy sources, such as the energy that pours down continuously from our sun. With the tremendous advances in harnessing and delivering economically viable solar energy, this is now readily available to us.

24. Solar energy: is absolutely clean is constantly renewable does not increase the carbon footprint slows the greenhouse effect in the atmosphere is an absolutely free and abundant energy source

25. Do solar panel installations have a beneficial effect? By going solar: one can reduce demand for fossil fuels limit greenhouse gas emissions, and as a result we will shrink the carbon footprint prevent acid rain and smog reduce water pollution

26. Installing even one solar energy system has a measurable effect on the environment. According to the U.S. Energy Information Administration the effect of switching one home from fossil-based energy to solar greatly reduces the damage to the atmosphere. They estimate that it has the same emissions reduction effect as planting over a hundred trees every year. In a city like New York alone, switching to a clean source of electricity like solar panels would eliminate the same amount of carbon emissions that would result from burning of nearly 3 tons of coal a year!

27. The health benefits of solar energy Because solar energy does not cause air pollution, the health benefits would be enormous. The National Renewable Energy Laboratory (NREL) suggests that: adopting solar energy usage on a large scale would significantly reduce nitrous oxides, sulfur dioxide, and particulate matter emissions, all of which can cause health problems. Among other health benefits, solar power could result in fewer cases of, respiratory and cardiovascular problems The result would be far fewer lost workdays related to health issues.

28. The benefit to the economy In addition to the benefit to the environment, solar energy can greatly benefit the world economy, because: Sourcing and extracting fossil fuels is expensive Solar energy is free and readily available The cost of producing it has dropped dramatically It is now economically viable for the average householder Requires no water in the production process Unlike traditional power plants, solar energy requires no water in the production process. Producing energy in traditional power plants, requires a constant supply of water for cooling purposes. This impacts directly on local water supplies, and also leads to water pollution problems.

29. The role we can play as individuals By investing in solar energy, we can each reduce our reliance on fossil fuels and participate in saving the environment. What greater benefit could there than to actively participate in making the world a healthier and safer place for future generations.