Assistant Professor

Chemistry

Ramabai Ambedkar Government Degree College

Gajraula, Amroha  U.P., India  

Renewable energy: Renewable energy is the energy obtained from those natural sources which replenishes very fast as it is consumed. Solar energy and wind energy are some examples of this energy. Renewable energy sources are available in very vast quantity and everywhere. 

Types of Renewable energy:

There are mainly six type of renewable energy available everywhere around the world. Except biomass energy all other renewable energies are very clean its meaning is that they do not release any harmful gases or pollutants in environment. These are green energy on nature. These energy sources can provide sustainable developments. 

1-Solar Energy: Solar energy is most abundant in comparison to the other energy sources. It can be obtained even in cloudy weather. Solar energy is being used in heating, cooling, natural lighting, electricity production, and as a fuel. Solar energy can be converted into electrical energy by photovoltaic panels in solar technology. Solar energy can be used as fuel when solar radiations are concentrated on a point through mirrors hemisphere. All the countries are not equally endowed of solar energy.

The cost of solar panel manufacturing has come down (plummeted) very fast in last decade.

Thus, solar panels are affordable now, in long run solar energy become very cheap.  Solar panels have about 30 years lifespan. They come in variety of shades depending upon the material used.

Solar energy minimise the harmful gases emissions caused by burning of fossil fuel and save us from many respiratory, lungs and kidney related diseases. It lowers the consumption of fossil fuel in the production of electrical energy. The word Carbon footprint is related to the greenhouse gases primarily with CO2.

For 1 MWh of solar energy produced, 0.5 to 1 ton of carbon dioxides offset. 

Solar penal:

2- Wind Energy:

Kinetic energy of moving air is harnessed to produce wind energy. In wind energy technology, we use large wind turbines. These are located on land (onshore) or in sea (offshore). In large wind turbines, large wings/blades are attached with shaft fitted in the turbine axle. These blades rotate when air move in a direction. These blades rotate the shaft in turbine which produce DC electrical energy. No water uses to cool wind turbine. Thus no water pollution is possible (except some exceptions). Wind energy has been exploited for millions of years. But today’s wind energy technologies have evolved in last decades. Now the electrical energy is being produced by wind turbines on large scale.

Sufficient potential exists in most of the regions of the world to produce wind energy. The worlds technical potential for wind energy is more than global electricity production.

Strong wind speed is obtained in remote hilly areas. Offshore wind power station has high potential to produce large wind electrical energy. Wind power plants creates second fastest growing good paying jobs in US. Wind power plants enables US economic growth.  US investment in wind power sector projects added $ 20 billion to the US economy. Wind power is a clean and renewable energy source. Wind power decrease the dependence on the quantities of power generated by fossil fuels; thus it lowers the concentration level of pollutants (dust, smoke, NO2, SO2, SO3, P2O3, CH4, N2O, CO2 etc) and greenhouse gases in environment.

Sustainable development is possible only when we use renewable source of energy. This energy is clean and green energy. The government has established laws and initiatives to attract international investments to speed up the energy production through renewable sources.

Wind Mill:  

 

3- Geothermal Energy:

It is accessible thermal energy from earth’s interior part. The heat can be extracted from geothermal reservoirs using wells. Some reservoirs are naturally sufficiently hot and accessible are known as hydrothermal reservoirs. Some reservoirs are naturally sufficiently hot but these are improved by hydraulic stimulation are known as enhanced geothermal system.

Fluids at various temperature can be used for electricity production. This energy production technology is mature and reliable. It is working for more than 100 years.

Main disadvantage of this technology is its high initial investment cost to develop infrastructure and several wells. There is high risk to prove the resource well at right place and depth. There is high noise and sight pollution. Discharge of gases and water with foul odours. However, when resource has been proven, annual fuel cost is low.

4- Hydropower:

In hydropower technique, energy is harnessed by the motion of water from high to low level. It can be obtained from rivers or reservoirs. Reservoir hydropower plants depends on the stored water at high level in reservoir. While river hydropower plants harness the energy from flow of the river.  

Hydropower reservoir can be used in multiple purposes like- water for irrigation, to control flood and drought, municipal drinking water, navigation service and electrical energy production.

Presently hydropower is largest source of renewable electrical energy. Its working depend on stable rainfall pattern. Its working may be hampered by climate induced drought or low rainfall.

The manufacturing of a hydropower plant put adverse impact on ecosystem. Many people thought that small scale hydropower plant is more eco-friendly and suitable for communities in remote areas.

A dam which create a reservoir may disrupt fish migration, stop natural river flow, divert silt loads, migration of inhabitants. All these changes affects ecosystem of that place. Reservoir may cover good agricultural land, archeological sites, natural resource areas etc. Aerobic and anaerobic decomposition of biomasses in reservoir may produce CO2 and CH4 in various amount depend upon local conditions. Hydropower turbine kills many aquatic animals during it working. China is largest hydroelectricity producer in the world.

Hydro power Plant:

5- Ocean Energy:

These technologies use kinetic and thermal energy of seawater. Ocean energy systems are in early stage of its development. A large number of prototype tidal and wave current devices are being explored.  Ocean cover about 70% surface of our planet. Only 2% freshwater is found in rivers, lakes and glaciers. They constantly keep in movement through waves, tides and currents. Waves develop due to wind. Tides develop due to gravity of moon and sun. Currents develop because of differences in water temperature and rotation of the planet. People have fun swimming in the waves. Current help in moving ships through ocean. Continuous movement of waves, tides and currents are used  to produce clean renewable energy for our schools, homes and industries. A special device is used to produce ocean energy. Certain parts of these devices move as the water moves and this movement generate electricity. Buoys and turbines are two devices used for this purpose. Buoy float on the sea and move up and down with waves. These operation derive piston and piston to generator.

Ocean Energy:

 

6. Bioenergy: 

Bioenergy is obtained from a variety of organic materials. These organic materials is known as biomass. Examples of Biomass are wood, charcoal, dung and straws/ remaining part of crops. These are used in heat production and electricity production. Mostly biomass is used for lighting, heating and cooking in rural areas by poor people in developing countries. Burning of biomass creates greenhouse gas emissions, but at lower level than burning fossil fuels.

Bioenergy should be used in very necessary works because it produce negative environmental impact. It also leads deforestation.                

Uses of renewable energy to save the environment:

(a) Uses of solar energy to save the environment:

1. No water is required in the function of solar panel. No any type of pollution take place during the function of solar panels.

2. Generating solar energy produce no emissions of harmful gases like- NO2, SO2, CH4, P2O3, CO2  etc.

 and particulate matters. It is also known as clean energy, that’s why it is called sustainable energy.

3. Solar energy can address problem of climate change due to the large amount of greenhouse gases in the environment.

4. This energy become very cheap after 5 years of installation of solar energy sources.

5. It generate three times more jobs than jobs in conventional energy sector.

6. Incoming rate of solar energy on earth is 10000 times more than the rate at which it is consumed by humans.=

7. It mitigates air pollution in the envronment thus save us from so many respiratory diseases.

8. It slow down climate change.

9. it lower the consumption of fossil fuel.

10. it reduces carbon footprint.

(b) Uses of  wind energy to save the environment:

1. Wind power is clean and renewable source of energy.

2. Wind power enables US economics growth

3. Wind power creating good paying jobs in US.

4. Wind turbine do not emit any pollutants in to air or in water.

5. Wind power is affordable. It is cheap and no fluctuation in price per unit of electricity. Because there is contract on fixed price for definite time period.

6. Operating wind power plants (in 2013) stop the release of about 2.5lakh metric tonnes of pollutants from entering environment. Wind vision research report that wind power will save emissions of about 12.3 Giga tonnes of greenhouse gases by 2050.

(c) Uses of geothermal energy to save the environment:

1. Main advantage of geothermal energy is to provide base load 24 hrs a day and 7 days per week. Whereas wind and solar energies are available for only 1/3 of the time.

2. The cost of geothermal energy comes between 5 to 10 cents per KWh. Which is comparable with other sources of renewable energy.

(d) Uses of hydropower energy to save the environment:

1. hydropower generator do not emit any air pollutants in environment.

2. hydropower plants work for 50 to 100 years of life span. Thus, it produces green energy for so long time.

3. It accounts for about 55% in global renewable energy production. Thus decrease 55% emissions of harmful pollutants in environment.

4. It is very clean source of energy. It is green energy.

5. It provide sustainable source of energy for human kind.

(e) Uses of Ocean energy to save the environment:

1. It is renewable energy because water of ocean will not run out like fossil fuel.

2. It does not produce greenhouse gases and other pollutants.

3. It does not contribute to global warming and climate change.

(f) Uses of Biomass energy to save the environment:

1. It produce less green house gases in comparison to fossil fuels

2. The ashes of biomass can be used as insecticides on plants.

Adverse effects of conventional energy techniques on the environment: Non-renewable energy sources are fossil fuels (petroleum, oil, coal and gas), woods, biogas, electrochemical energy and combustible gases ( H2, Hydrocarbon). Here, fossil fuel take million of years to form. Fossil fuel when burnt produce large amount of greenhouse gases (CO2, CH4, N2O) with high amount of oxides of nitrogen, phosphorous and sulphur.

References:

1. Climate action, United Nations. What is renewable energy.

https://www.un.org/en/climatechange/what-is-renewable-energy#:~:text=

Renewable%20energy%20is%20energy%

20derived,plentiful%20and%20all%20around%20us.

2. Suntuity, Environmental benefits of solar energy. https://suntuity.in/environmental-benefits

3.Advantages and challenges of wind energy. 

https://www.energy.gov/eere/wind/advantages-and-challenges-wind-energy#:~:text=

Wind%20power%20is%20a%20clean%20and%20renewable%20energy%

20source.&text=Wind%20energy%20helps%20avoid%20329,%2C%20smog%2C%20and%20greenhouse%20gases.

4. R M Bakshi, The economic times, How wind power can enable a sustainable life. 30 may 2022.

5. Environmental effects and economic costs, Britannica.com, https://www.britannica.com/science/geothermal-energy/Environmental-effects-and-economic-costs

6.US Energy information administration, EIA, Hydropower explained, hydropower and the environment. https://www.eia.gov/energyexplained/hydropower/hydropower-and-the-environment.php

7. M. Luisa Martinez, Rodolfo Silva, Janaina Garcia. Frontiers, How can we use ocean energy to generate electricity. August 9 2021.