MEV 014: Unit 12 – Wind Energy and Geothermal Energy

-

 UNIT 12: WIND ENERGY AND GEOTHERMAL ENERGY

12.0 Introduction

Energy is essential for development, and as conventional resources deplete, the world is turning toward renewable sources. Two promising renewable sources are wind energy and geothermal energy. Wind energy uses the power of moving air to generate electricity, while geothermal energy uses heat from within the Earth. Both are clean, sustainable, and have great potential for reducing dependency on fossil fuels.

12.1 Objectives

After studying this unit, you will be able to:

·         Understand the sources and principles behind wind and geothermal energy.

·         Learn the methods of harnessing wind energy using turbines.

·         Describe the types and advantages of wind turbines.

·         Understand the sources and types of geothermal energy.

·         Learn about aquifer and underground thermal energy storage systems.

·         Explore the status and potential of wind and geothermal energy in India.

12.2 Wind Energy / Wind Power

Wind energy is produced by harnessing the kinetic energy of wind through turbines. As wind moves, it turns the blades of wind turbines, which spin a shaft connected to a generator, producing electricity.

Wind energy is:

·         Renewable

·         Clean (zero emissions)

·         Abundant in many parts of the world

12.3 Harnessing of Wind Energy

12.3.1 Process of Harnessing of Wind Energy

1.      Wind Flow: Air movement is caused by solar heating of the Earth's surface.

2.      Turbine Blades: Wind turns large blades connected to a rotor.

3.      Gearbox and Generator: The rotor turns a shaft inside the nacelle (housing), which spins a generator.

4.      Electricity Generation: The generator converts mechanical energy into electrical energy.

5.      Transmission: Electricity is sent to homes or the grid.

Wind energy is mostly harnessed in wind farms, where multiple turbines operate together.

12.3.2 Advantages of Harnessing Wind Energy

·         Clean and eco-friendly (no greenhouse gases)

·         Cost-effective in the long run

·         Scalable from small farms to large utilities

·         Saves fossil fuels

·         Suitable for remote areas

12.3.3 Types of Windmills / Wind Turbines

1.      Horizontal Axis Wind Turbines (HAWT):

o    Most common type

o    Blades rotate on a horizontal axis

o    High efficiency and power output

2.      Vertical Axis Wind Turbines (VAWT):

o    Blades rotate on a vertical axis

o    Operate in variable wind directions

o    Easier to maintain but less efficient

Other types: Offshore turbines (in the sea), Onshore turbines (on land)

12.4 Wind Energy / Wind Power in India

India has immense wind energy potential, especially in states like:

·         Tamil Nadu

·         Gujarat

·         Maharashtra

·         Karnataka

·         Rajasthan

As of recent years, India is among the top five wind power producers globally. The Ministry of New and Renewable Energy (MNRE) promotes wind power projects and incentives. Wind energy contributes significantly to India's renewable energy mix.

12.5 Geothermal Energy

Geothermal energy is the heat stored beneath the Earth’s surface. It originates from the radioactive decay of minerals and the original formation of the Earth.

12.5.1 Sources of Geothermal Energy

·         Hot dry rocks deep beneath the surface

·         Hot water reservoirs

·         Geothermal steam fields

·         Magma (in rare cases)

Geothermal sources can be accessed using wells and used directly or for electricity generation.

12.5.2 Harnessing of Geothermal Energy

There are three main technologies:

1.      Dry Steam Plants – Use steam directly from underground to turn turbines.

2.      Flash Steam Plants – Use hot water, which rapidly turns to steam when pressure is released.

3.      Binary Cycle Plants – Transfer heat to another liquid with a lower boiling point to generate steam and power turbines.

12.5.3 Types of Geothermal Energy

1.      Low-temperature: Direct use for heating buildings, greenhouses, etc.

2.      Medium-temperature: Useful in combined heat and power (CHP) systems.

3.      High-temperature: Suitable for electricity generation.

12.6 Geothermal Energy and Its Potential in India

India lies in a tectonically active zone with geothermal potential in:

·         Puga Valley (Ladakh)

·         Manikaran (Himachal Pradesh)

·         Tapovan (Uttarakhand)

·         Sohna (Haryana)

·         Tattapani (Chhattisgarh)

·         Godavari Basin (Andhra Pradesh)

Although geothermal energy is underutilized in India, studies and pilot projects are ongoing. It is seen as a promising option for direct heating and power production in remote and cold regions.

12.7 Aquifer Thermal Energy Storage (ATES)

Aquifer Thermal Energy Storage is a method to store thermal energy in underground water-bearing formations (aquifers) and use it later for heating or cooling buildings.

12.7.1 Principles of ATES

·         During summer: Excess heat is stored in underground water.

·         During winter: The stored heat is extracted for use.

·         Cold can also be stored in winter for cooling in summer.

ATES uses heat pumps and wells to inject and extract water from the aquifer.

12.7.2 Underground Thermal Energy Storage (UTES)

UTES includes:

·         Borehole Thermal Energy Storage (BTES)

·         Cavern Thermal Energy Storage

·         Aquifer Thermal Energy Storage

It is a seasonal energy storage system using the ground as a natural battery.

12.7.3 Applications of UTES

·         Heating and cooling buildings

·         Greenhouse heating

·         District heating systems

·         Industrial processes

·         Integration with solar and geothermal systems

These systems help reduce dependency on fossil fuels and improve energy efficiency.

12.8 Let’s Sum Up

Wind and geothermal energy are crucial for a sustainable energy future. Wind energy is a well-established technology in India with large-scale applications, while geothermal energy offers untapped potential, especially in specific regions. Both are clean, renewable, and have low environmental impact. New technologies like Aquifer and Underground Thermal Energy Storage provide innovative ways to store and use energy efficiently. As India moves towards energy security and climate goals, wind, geothermal, and thermal storage systems will play an increasingly important role.

 

Comments

Post a Comment

Popular Posts

Jcert Class 8 Daffodil Chapter 1a: The Naive Friends Solutions

-
Chapter 1a : The Naive Friends Answer the following questions: 1. Which questions made Keshav and Shyama curious about the egg? Ans.         How did the chick come out? How big would the eggs? How many? What colours would they? What did they eat? Such types of questions made Keshav and Shyama curious about the egg. 2. What three things did the children do to protect the eggs? Ans.         The children done three things are: (i)          Adjustment of food. (ii)        Adjustment of water. (iii)      Adjustment of roof. 3. Why did Keshav think of making a cushion for the eggs? Ans.         When Keshav saw the egg on direct sun light, he thaught making a cushion for the eggs. 4. What excuse did Keshav give for not showing the eggs to Shyama? Ans.     ...
Read more

Jcert Class 8 भाषा मंजरी Chapter 3 मित्रता Solutions

-
अध्याय - 3 : मित्रता 1. आप किस प्रकार कह सकते हैं कि मित्रों के चुनाव की उपयुक्तता पर हमारे जीवन की सफलता निर्भर करती है? उ. मित्रों के चुनाव की उपयुक्तता पर हमारे जीवन की सफलता निर्भर करती है क्योंकि संगति का गुप्त प्रभाव हमारे आचरण पर पड़ता है और यदि हमें अच्छी संगति, अच्छे मित्र मिलते हैं तो वे हमें सफलता की ओर ले जाते हैं जबकि बुरी संगति हमारे जीवन को खाक में मिला देती है।  2. 'विश्वासपात्र मित्र जीवन की एक औषध है।' आशय स्पष्ट कीजिए। उ. 'विश्वासपात्र मित्र जीवन की एक औषध है'- ऐसा इसलिए कहा गया है कि यदि हमें विश्वासी मित्र मिल गया तो हम अपने जीवन में चाहे जैसा भी कदम उठाएँ, उस कदम की आलोचना करके वह हमें सही दिशा की ओर उन्मुख करेगा। हम अपनी गलती रूपी बीमारी को उसकी आलोचना रूपी औषधि से दूर कर सकेंगे।  3. मित्र का चुनाव करते समय हमें किन बातों का ध्यान रखना चाहिए? उ. मित्र का चुनाव करते समय हमें निम्नलिखित बातों का ध्यान रखना चाहिए हमारे अच्छे विचारों (संकल्पों) को दृढ़ करने वाला हो। हमें दोषों और त्रुटियों से बचाए। हमारे सत्य, पवित्रता ...
Read more

Jcert Class 8 भाषा मंजरी Chapter 8 अमरूद का पेड Solutions

-
अध्याय - 8 : अमरूद का पेड 1. लेखक को क्यों लगता है कि इन सब पिछड़े खयालातों का हमारे घर में गुजर नहीं हो सकेगा। उ. अमरूद के पेड़ को देखकर सबसे पहले बाबू कन्हैयालाल की बूढ़ी पत्नी ने एक दिन टोका कि पश्चिम की तरफ अगर मकान का मुखड़ा हो और सामने ही अमरूद का पेड़ तो 'राम-राम बड़ा अशुभ होता है और माँ के चेहरे पर थोड़ा-सा भय दिखा पर लेखक को विश्वास था कि इन सब पिछड़े खयालातों का हमारे घर में गुजर नहीं हो सकेगा क्योंकि उसके घर के लोग आधुनिक विचारधारा के थे उसकी माँ सत्याग्रह के दिनों में अजमेर में लम्बा जेल कर चुकी है। पिताजी खुद राजनैतिक सामाजिक उदारता वाले आदमी थे। बुआ ने विवाह नहीं किया था, पढ़ने-लिखने में ही अपनी सम्पूर्ण जिन्दगी लगा दी और समाज कोई चुनौती देने का साहस नहीं कर सका। साथ ही परिवार के सभी लोगों में पिछड़ेपन के प्रति भर्त्सना का भाव था। 2. अमरूद के पेड़ की छाया किस प्रकार लेखक को उनके भाई-बहनों के साथ जोड़ती है ? उ. अमरूद के पेड़ की छाया लेखक को उसके भाई-बहनों के साथ जोड़ती है। वे सभी अमरूद की छाया में बेंत की कुर्सियों पर बैठ चर्चाएँ करते थे जिससे उनके बीच...
Read more