Question 77 from UPSC CSE 2014 - Science and Technology

Question

With reference to technology for solar power production, consider the following statements:
1. 'Photovoltaics' is a technology that generates electricity by direct conversion of light into electricity, while 'Solar Thermal' is a technology that utilizes the Sun's rays to generate heat which is further used in the electricity generation process.
2. Photovoltaics generates Direct Current (DC), while Solar Thermal generates Alternating Current (AC).
3. India has a manufacturing base for Photovoltaics technology, but not for Solar Thermal.
Which of the statements given above is/are correct?

Accepted Answer

Correct Option: A. 1 only

Strategy: - Differentiate between photovoltaic (PV) and solar thermal technologies based on their core principles: PV generates DC electricity, while solar thermal generates heat.
- Evaluate statement 1 as accurate based on this differentiation.
- Dismiss statement 2 for its incorrect DC versus AC contrast.
- Dismiss statement 3 because India has a manufacturing base for both technologies.
- Conclude that only statement 1 is correct.

Key Info: **Photovoltaic (PV) Technology**
- Uses semiconducting materials, such as silicon, to convert sunlight directly into electricity through the photovoltaic effect.
- The initial output is direct current (DC), which is typically converted to alternating current (AC) by inverters for grid integration.

**Solar Thermal Technology**
- Employs mirrors or lenses to concentrate sunlight, producing high temperatures that heat a fluid.
- The heated fluid creates steam to drive turbines for electricity generation.
- This process does not generate AC by itself; electricity is produced via conventional turbine generators.

**Manufacturing in India**
- India has a strong and expanding PV manufacturing base, producing modules, cells, and supporting equipment.
- The country also has solar thermal manufacturing capabilities, primarily for solar water heaters and some components for concentrated solar power (CSP) plants, although large-scale CSP deployment is limited.
- The National Solar Mission promotes the development of both PV and solar thermal technologies.

**Key Differences and Examples**
- **Core Function:** PV generates electricity directly, whereas solar thermal generates heat for indirect electricity production.
- **Initial Output:** PV produces DC; solar thermal produces heat.
- **Indian Projects:** Large solar parks like Pavagada and Bhadla are predominantly PV-based. CSP installations are fewer, with notable projects in Rajasthan and Gujarat.

Answer

Option B: 2 and 3 only

Answer

Option C: 1, 2, and 3

Answer

Option D: None of the above