From UPSC perspective, the following things are important :
Prelims level : Types of technologies in PV cells
Mains level : Paper 3- Adoption of new technologies in solar power sector
Large-scale solar projects in Tamil Nadu have seen rapid growth in recent years. By embracing advances in solar technologies, India can continue to lead in this sector.
Factors driving growth
- In the past five years, the cumulative installed capacity witnessed a four-fold increase in Tamil Nadu to 4.4 GW, as of March 2021.
- High insolation level: Aiding this capacity addition is the State’s reasonably high insolation levels and matching solar potential, estimated at 279GW.
- Decline in price: The sharp decline in the prices for solar and resulting cost competitiveness is another factor.
- National target: Additionally, in response to the ambitious national targets and to spur sector specific development, Tamil Nadu released the Solar Policy of 2019, aiming for 9GW of solar installations by 2023.
Type of technology use for solar panel
- 1) Mono-crystalline Vs multi-crystalline panels: ‘First-generation’ solar cells use mono-crystalline and multi-crystalline silicon wafers.
- The efficiency of mono-crystalline panels is about 24%, while for multi-crystalline panels it is about 20%.
- Mono-crystalline cells are dominant today.
- Although mono-crystalline panels are priced higher than multi-crystalline ones, the difference is diminishing and will soon attain parity.
- This would result in mono panels being preferred over multi due to their higher efficiency, greater energy yield and lower cost of energy.
- 2) Bifacial solar cells: Newer technologies incorporating crystalline silicon focus on bifacial solar cells, capable of harvesting energy from both sides of the panel.
- Bifacials can augment the power output by 10-20%.
- Within this, the Passive Emitter and Rear Contact technology is predicted to gain popularity. However, it is yet to achieve price parity for large-scale deployment.
- 3) Thin-film technologies: It is classified as the ‘second generation of solar PVs.
- In addition to being used in solar farms and rooftops, thin films with their low thickness, light weight and flexibility are also placed on electronic devices and vehicles, power streetlights and traffic signals.
- Mainstream thin films utilise semiconductor chemistries like Cadmium Telluride with module efficiencies of around 19%.
- Other technologies include Amorphous Silicon and Copper Indium Gallium Di-Selenide.
- Nanocrystal and dye-sensitised solar cells are variants of the thin film technology. These are in early stages for large-scale commercial deployment
- However, the efficiency of thin films is lower than that of crystalline silicon.
- 4) Perovskite: These are grouped as ‘third generation’ and contain technologies such as perovskite, nanocrystal and dye-sensitised solar cells.
- Perovskites have seen rapid advances in recent years, achieving cell efficiency of 18%.
- They have the highest potential to replace silicon and disrupt the solar PV market, due to factors such as ease of manufacture, low production costs and potential for higher efficiencies.
- 5) Use of Graphene Quantum-dots: Graphene is made of a single layer of carbon atoms bonded together as hexagons.
- Solar cells made of graphene are of interest due to high theoretical efficiency of 60% and its super capacitating nature.
- Quantum-dot PVs use semiconductor nanocrystals exhibiting quantum mechanical properties capable of high efficiency of about 66%.
- However, both these are in the early stages of research.
Technologies to better integrate solar PVs into the grid
- These technologies include weather forecasting and power output prediction systems; operation monitoring and control systems; and scheduling and optimisation systems.
- Additionally, automatic systems have been developed for the smooth resolution of output fluctuations.
- A portion of the budget for renewable energy targets should be set aside exclusively for new technologies.
- Grants and subsidies can also be provided for their adoption.
- Efforts must be taken to address gaps in research, development, and manufacturing capabilities in the solar sector through sector-specific investment and incentives.
- There must also be greater industry-academia collaborations and funding opportunities for startups.
- A comprehensive sector-specific skilling programme is also required for workers.
All these efforts would help the country become a global player in the solar power sector.