Alternative Energy Technologies — PYQs
1. Introduction — Alternative Energy Technologies
- Alternative Energy Technologies are crucial for sustainable development and energy security, frequently featuring in UPSC Prelims.
- This section covers key alternative energy terms asked in previous year questions.
KNOWLEDGE NUGGET
- Alternative Energy: Energy sources that do not rely on fossil fuels
- Key Areas: Solar, wind, nuclear, hydrogen, bioenergy, geothermal, ocean energy, fuel cells
2. Alternative Energy Technologies — Previous Year Questions
2021 — SODIUM LAMPS & LED LAMPS
- Sodium vapor lamps: Gas-discharge lamps emitting light by exciting sodium atoms to produce a distinctive at around 589 nm wavelength.
- Used in street lighting; come in two types — low pressure and high pressure sodium lamps.
- The spectrum of visible light from sodium lamps is almost monochromatic and has a shorter lifespan compared to LEDs.
2016 — INTERNATIONAL THERMONUCLEAR EXPERIMENTAL REACTOR (ITER)
- A large-scale scientific experiment aimed at demonstrating the feasibility of fusion energy for commercial use.
- An international collaboration involving multiple countries, designed to replicate the sun's nuclear fusion process to produce clean, limitless energy.
2015 — FUEL CELLS
- Devices that convert chemical energy from fuel into electricity through a chemical reaction.
- Offer high efficiency and low emissions; used for powering space capsules and satellites, power generation, etc.
- The working of this fuel cell involved the passing of hydrogen and oxygen into a concentrated solution of sodium hydroxide via carbon electrodes.
2014 — PHOTOVOLTAICS (PV)
- A technology that converts sunlight directly into electricity using semiconductor materials.
- A sustainable and renewable energy source, crucial for reducing carbon emissions.
- PV systems are versatile, used in various scales from small gadgets to large solar power plants.
2014 — SOLAR THERMAL ENERGY
- Involves harnessing the sun's heat to generate thermal energy for heating or electricity production.
- Uses mirrors or lenses to concentrate sunlight onto a receiver, where the heat is captured and converted into usable energy.
- Offers a renewable and clean power source.
2011 — MICROBIAL FUEL CELLS
- A bioelectrochemical device in which electrical power is obtained from the energy in chemical bonds of an organic substrate.
- Operates in oxygen-limited conditions by the action of electroactive microbial species like Nocardia, E. coli, etc.
3. Important Terms in News
COAL GASIFICATION
- A thermo-chemical procedure wherein the pressure and heat of the gasifier disintegrates coal into its chemical components, resulting in production of Syngas.
- Syngas is mostly Carbon Monoxide (CO) and Hydrogen (H₂), with other gaseous substances such as Hydrogen Sulphide (H₂S) and Carbon dioxide (CO₂).
CRITICALITY IN A NUCLEAR PLANT
- Refers to a condition when each fission event releases a sufficient number of neutrons to sustain an ongoing series of reactions.
- The first criticality is the start of a controlled fission chain reaction.
- After the fission, the heat is used to make steam that turns a turbine and produces electricity.
E-FUELS (Electrofuels)
- A type of synthetic fuels that can be used to power vehicles, ships, and aeroplanes.
- Made from captured Carbon Dioxide or Monoxide and hydrogen obtained from water split.
HYGROELECTRICITY
- Refers to generation of electricity from air humidity.
- Electricity is harvested through a small device with two electrodes and a nanoporous material.
- When water molecules pass through these nanopores, they create an electric charge imbalance, turning the device into a mini battery.
LOW TEMPERATURE THERMAL DESALINATION (LTTD) TECHNOLOGY
- Exploits the difference in temperature (nearly 15°C) in ocean water at the surface and at depths of about 600 feet.
- Warmer water at the surface is condensed, whose pressure has been lowered using vacuum pumps.
- Such depressurised water can evaporate even at ambient temperatures and result in vapors which when condensed are free of contaminants.
SMALL MODULAR REACTORS (SMRs)
- Advanced nuclear reactors with power generation capacity ranging from less than 30 MWe to 300+ MWe.
- Capable of generating substantial low-carbon electricity.
4. Summary: Alternative Energy Technologies at a Glance
| Year | Term | Key Description |
|---|---|---|
| 2021 | Sodium Lamps & LED Lamps | Gas-discharge lamps emitting at 589 nm; monochromatic; shorter lifespan than LEDs |
| 2016 | ITER | International collaboration for nuclear fusion energy; replicates sun's fusion process |
| 2015 | Fuel Cells | Convert chemical energy to electricity; high efficiency, low emissions; H₂ and O₂ |
| 2014 | Photovoltaics (PV) | Converts sunlight to electricity using semiconductors; sustainable, renewable |
| 2014 | Solar Thermal Energy | Harnesses sun's heat using mirrors/lenses to concentrate sunlight |
| 2011 | Microbial Fuel Cells | Bioelectrochemical device using electroactive microbes (Nocardia, E. coli) |
Key Takeaways for UPSC
- ITER: International Thermonuclear Experimental Reactor — nuclear fusion energy
- Fuel Cells: Convert chemical energy to electricity — H₂ and O₂ reaction
- Photovoltaics: Direct sunlight to electricity using semiconductors
- Solar Thermal: Concentrated sunlight for heat/electricity
- Microbial Fuel Cells: Electricity from organic substrates using microbes
- Criticality: Sustained nuclear fission chain reaction
- Coal Gasification: Produces Syngas (CO + H₂) from coal
- E-Fuels: Synthetic fuels from captured CO₂ and hydrogen
- Hygroelectricity: Electricity from air humidity
- LTTD: Low Temperature Thermal Desalination — ocean temperature difference
- SMRs: Small Modular Reactors — 30-300+ MWe nuclear reactors
High-Yield Interactive UPSC Quiz (Alternative Energy Technologies)
Q1. ITER is an international project for:
Correct Answer: C. ITER (International Thermonuclear Experimental Reactor) is a large-scale scientific experiment aimed at demonstrating the feasibility of fusion energy for commercial use.
Q2. Fuel cells convert chemical energy into:
Correct Answer: B. Fuel cells are devices that convert chemical energy from fuel into electricity through a chemical reaction. They offer high efficiency and low emissions.
Q3. Photovoltaics convert sunlight into electricity using:
Correct Answer: C. Photovoltaics (PV) is a technology that converts sunlight directly into electricity using semiconductor materials.
Q4. Sodium vapor lamps emit light at which wavelength?
Correct Answer: C. Sodium vapor lamps emit light at around 589 nm wavelength by exciting sodium atoms.
Q5. Microbial fuel cells use which microorganisms to generate electricity?
Correct Answer: C. Microbial fuel cells are bioelectrochemical devices that use electroactive microbial species like Nocardia and E. coli to generate electricity from organic substrates.
Q6. Criticality in a nuclear plant refers to:
Correct Answer: C. Criticality in a nuclear plant refers to a condition when each fission event releases a sufficient number of neutrons to sustain an ongoing series of reactions.
Q7. Syngas produced from coal gasification is mostly composed of:
Correct Answer: B. Syngas is mostly Carbon Monoxide (CO) and Hydrogen (H₂), with other gaseous substances such as Hydrogen Sulphide (H₂S) and Carbon dioxide (CO₂).
Q8. E-Fuels are synthetic fuels made from:
Correct Answer: C. E-Fuels (Electrofuels) are synthetic fuels made from captured Carbon Dioxide or Monoxide and hydrogen obtained from water split.
Q9. Low Temperature Thermal Desalination (LTTD) technology uses temperature difference in ocean water at depths of about:
Correct Answer: C. LTTD exploits the difference in temperature (nearly 15°C) in ocean water at the surface and at depths of about 600 feet.
Q10. Small Modular Reactors (SMRs) have power generation capacity up to:
Correct Answer: D. Small Modular Reactors (SMRs) are advanced nuclear reactors with power generation capacity ranging from less than 30 MWe to 300+ MWe.