Study Notes on Non-Conventional Energy Sources

Module Overview

  • Module 4: Non-Conventional Energy Sources
  • Elective 2: Environmental Chemistry and Non-Conventional Energy Sources
  • Semester: II, 2025-26
  • Course Code: BSC2032

Conventional Energy Sources

  • Definition: Sources that have been traditionally used for power generation and energy.

Types of Conventional Energy Sources

  • Fossil Fuels:
      - Coal
      - Oil
      - Natural Gas
  • Nuclear Energy

Limitations of Conventional Energy Sources

  • Cost:
      - High production costs which are continuously rising.
  • Extraction Impacts:
      - Mining and drilling cause:
        - Habitat destruction
        - Oil spills
        - Water contamination
  • Finite Resources:
      - These sources are exhaustible and will eventually deplete. Availability is subject to market and political discourse.
  • Environmental Degradation:
      - Burning fossil fuels releases CO2 and other pollutants impacting climate with global warming, acid rain, and smog.
  • Health Hazards:
      - Pollution from fossil fuels leads to respiratory diseases and other health issues.
  • Geopolitical/Supply Risk:
      - Dependence on specific extraction locations leads to supply instability and fluctuating costs.
  • Safety Risks (Nuclear):
      - Risks associated with radiation accidents and challenges in radioactive waste disposal.

Non-Conventional Energy Sources

Types of Non-Conventional Energy Sources

  • Solar Energy
  • Wind Energy
  • Geothermal Energy
  • Biomass Energy
  • Tidal Energy

Advantages of Non-Conventional Energy Sources

  • Renewable and Sustainable:
      - Naturally replenished and will not deplete like fossil fuels.
  • Low Operating Costs:
      - Initial infrastructure costs can lead to free or significantly lower long-term operational costs.
  • Environmentally Friendly:
      - Produce minimal to no greenhouse gases or pollutants, aiding in climate change mitigation.
  • Improved Public Health:
      - Cleaner air/water improves public health and reduces healthcare costs.
  • Enhanced Energy Security:
      - Utilizing domestic resources reduces dependency on imports thereby improving energy independence.
  • Adaptability:
      - Utilized for various applications: electricity generation, transportation, and heating.
  • Resource Conservation:
      - Helps to conserve finite resources by utilizing renewable sources.
  • Job Creation:
      - Expanding renewable energy sectors generate employment in various fields.
  • Stable Energy Prices:
      - Resilience against geopolitical and market price fluctuations.

Investment Trends in Renewable Energy

  • Annual Financial Commitments (2013-2022):
      - Solar PV and Onshore Wind dominated investments, with allocations of 46% and 32%, respectively.
      - Offshore Wind received 8% and Solar Thermal, 5%.
      - Other technologies (hydropower, biomass, etc.) received only 7% cumulatively.
  • Increase in Investment in 2022:
      - 95% of overall investments concentrated in solar and wind technologies.

Renewable Energy Employment by Country and Technology (2023)

Employment Statistics (Global)

  • Total employment across technologies is 7,106,000.
  • Breakdown:
      - Solar Photovoltaic: 16,233
      - Liquid Biofuels: 2,803
      - Hydropower: 2,323
      - Wind Energy: 1,456
      - Solid Biomass, Geothermal Energy, etc.

Employment Statistics (India)

  • Total renewable energy employment is 1,019,000.
  • Breakdown:
      - Hydropower: 453
      - Solar Photovoltaic: 319

Trends in Renewable Energy Capacity in India

Installed Capacity by Source (as of May 2023)

  • Total Installed Capacity: 417.7 GW
      - Renewables: 125.7 GW (+15.8 GW since March 2022)
      - Coal: 60 GW
      - Wind: 60 GW
      - Nuclear: 6.8 GW

Renewable Energy Mix (May 2024)

  • Breakdown of capacity:
      - Wind: 32%
      - Solar: 57%
      - Biomass: 7%
      - Others: 4%

Differences Between Conventional and Non-Conventional Energy Sources

Conventional Energy Sources

  • Finite: Exhaustible resource.
  • Pollution: Contributes to greenhouse effects, acid rain, and smog.
  • Reliability: Continuous energy supply yet subject to availability constraints.
  • Cost: Higher and increasing.

Non-Conventional Energy Sources

  • Renewable: Virtually inexhaustible.
  • Pollution: Produces negligible emissions.
  • Availability: Not an issue in terms of resource depletion.
  • Cost: Lower operating costs, but high initial capital investment required.

Hydropower

Overview

  • Definition: Renewable energy harnessing kinetic and potential energy from water movement.
  • Electricity Conversion: Water flow spins turbines linked to generators.
  • Market Presence: Accounts for approximately 71% of all renewable electricity generation globally.

Key Components

  • Dam & Reservoir: Stores water, creating potential energy.
  • Penstock: Pipe channeling water from reservoir.
  • Turbine: Converts kinetic energy to mechanical energy.
  • Generator: Transforms mechanical energy into electrical energy.
  • Draft Tube & Outflow: Re-releases water into the environment post-generation.

Applications

  • Residential and commercial electricity supply.

Advantages of Hydropower

  • Clean Energy Source: Sustainable; no emissions during operation.
  • Reliable: Consistent power generation, efficiency of 90-95%.
  • Versatile Applications: Can provide flood control, irrigation.
  • Cost-Effective: Long lifespan (>50 years) with lower operational costs.

Disadvantages of Hydropower

  • High Construction Costs: Significant initial investment required for infrastructure.
  • Environmental Impact: Potential alterations to ecosystems, risks of flooding, and displacement.
  • Reliability on Water Availability: Droughts heavily impact energy output.

Environmental Impact of Hydropower

  • Ecosystem Change: Changes water temperature, interrupts fish migration, and affects biodiversity.
  • Space Utilization: Requires large areas of land, displacing communities.

Tidal Energy

Overview

  • Definition: Energy derived from the gravitational pull of the Moon and the Sun on Earth's oceans. Highly predictable and renewable.

How It Works

  • Tidal Turbines: Installed in high tidal activity areas, converting kinetic energy from tides into electricity.
  • Technologies for Harnessing:
      - Tidal Stream Generators: Similar to underwater wind turbines.
      - Tidal Barrages: Structures that harness tidal flow for energy generation.
      - Tidal Lagoons: Enclosed areas capturing and releasing water through turbines.

Advantages of Tidal Energy

  • Renewable & Predictable: Cycles can be predicted, making them reliable.
  • High Energy Density: Water’s density allows for energy production even at lower speeds.
  • Long Operational Lifespan: Tidal power plants have low environmental impact and longevity.

Limitations of Tidal Energy

  • High Initial Costs: Extensive engineering and development are required.
  • Environmental Concerns: Possible disruption of ecosystems with barrages.
  • Location Limitations: Suitable only in specific coastal locations with high tidal ranges.
  • Corrosion Concerns: Maintenance is intensive to withstand saltwater conditions.

Wind Energy

Overview

  • Definition: Energy derived from wind, a byproduct of solar heating of the atmosphere.
  • Types of Wind Power:
      - Onshore: Turbines located on land.
      - Offshore: Turbines located in water bodies, often more efficient.

how It Works

  • Working Mechanism:
      - Wind flows over rotor blades causing lift and drag, producing rotation.
      - This drives a generator, converting mechanical energy to electricity.

Components

  • Rotor: Captures wind energy.
  • Gearbox: Increases rotation speed.
  • Generator: Converts mechanical energy to electricity.
  • Transformer: Manages electricity output.

Advantages of Wind Power

  • Renewable & Abundant: Wind is free and abundant; provides no emissions.
  • Cost-Effective: Competitive prices with improved technology.
  • Land Adaptability: Fits well into multiple-use rural areas.

Limitations of Wind Power

  • Variable Production: Weather-dependent; not always reliable.
  • Location Constraints: Suitable wind fields often far from demand centers.
  • Environmental Concerns: Risks to wildlife, visual aesthetics, and noise pollution.

Solar Energy

Overview

  • Definition: Energy harnessed from sunlight through various technologies (photovoltaic, solar thermal).
  • Potential: Global solar energy far exceeds total energy needs.

Types of Solar Power

  • Solar Thermal: Converts sunlight into heat.
  • Photovoltaic: Converts sunlight directly into electricity.

Applications

  • Household Electricity Generation: Installation on rooftops.
  • Industrial Applications: Utilized in factories for energy.

Advantages and Disadvantages of PV Cells

Advantages

  • Clean: No emissions; renewable resource.
  • Cost-Effective: Declining costs makes it affordable.

Disadvantages

  • Efficiency: Often around 30% efficiency.
  • Land Requirement: Requires substantial space for significant generation.
  • Dependence on Weather: Ineffective at night or during cloudy days.

Geothermal Energy

Overview

  • Definition: Heat energy from within the Earth; renewable and sustainable.

Mechanism of Electricity Generation

  • Utilizes heated steam to power turbines, generating electricity.
  • Systems promote direct use for heating applications, agriculture, and recreation.

Advantages of Geothermal Energy

  • Low-Carbon Emissions: Minimal impact on greenhouse gas emissions.
  • Sustainable: Continuous heat production makes it reliable.

Limitations of Geothermal Energy

  • High Upfront Cost: Drilling and exploration costs are significant.
  • Geographic Limitations: Suitable sites mostly near volcanic regions.

Environmental Impact of Geothermal Energy

  • Land Use: Small footprint, limited use for other land applications.
  • Biodiversity: Risk of affecting regional biodiversity.

Study Questions

  • Define non-conventional energy sources. Explain the limitations of conventional energy sources.
  • Name renewable energy sources and state their advantages.
  • Distinguish between conventional and non-conventional sources of energy.
  • Write short notes with advantages and limitations on hydro energy and tidal energy.
  • What is the environmental impact of wind and solar power plants on the environment?
  • Draw the flow diagram, state the components and explain the working of a wind power plant. What factors affect conversion efficiency?
  • Discuss the merits and demerits of photovoltaic cells and their operation with a sketch.