Solar Cell

A solar cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is an physical and chemical phenomenon. A solar cell, a type of photoelectric cell, directly converts light energy into electricity. These individual cells are the building blocks of photovoltaic modules, commonly known as solar panels

Almost all of the commercial PV cells consist of crystalline silicon, with a market share of 95%. Cadmium telluride (CdTe) thin-film solar cells hold a strong position in the market, capturing around 5% of the global solar cell share. An array of interconnected solar cells directly converts sunlight into a usable amount of direct current (DC) electricity

Solar cells are like tiny factories that turn sunlight into electricity. Imagine little power plants that use sunshine instead of burning fuel! Heres what they're used for:

  • Big power plants: Lots of solar cells together create solar farms that generate electricity for entire towns and cities.
  • Homes and businesses: Solar panels on rooftops use sunshine to power houses and buildings.
  • Off-the-grid living: In remote areas without power lines, solar cells provide electricity for homes and cabins.
  • Small electronics: Calculators, portable phone chargers, and even some toys use tiny solar cells.

Process for solar cell manufacturing:

The Heart of Photovoltaic Power: Transforming Silicon Wafers into Solar Cells

Solar cell manufacturing is a fascinating dance between material science, physics, and meticulous engineering. Here's a closer look at the key steps involved in transforming silicon wafers into electricity-generating powerhouses:

  1. Silicon Processing:
  • Crystal Growth: Ultra-pure silicon, the base material, undergoes a process like the Czochralski method. Molten silicon is slowly pulled from a crucible, forming a cylindrical crystal ingot with a near-perfect crystalline structure.
  • Wafering: These ingots are sliced into thin wafers using diamond-coated wire saws. The precise thickness is crucial for light absorption and electrical properties.
  1. Wafer Cleaning and Texturing:
  • Cleaning: The wafers are meticulously cleaned with chemicals and deionized water to eliminate any surface contaminants that could hinder light absorption or electrical flow.
  • Texturing: The smooth wafer surfaces are then textured using techniques like chemical etching or laser ablation. This creates microscopic peaks and valleys, increasing the surface area and light trapping efficiency within the cell. Light bounces around more within the textured surface, maximizing the chance of it being absorbed by the silicon.
  1. Junction Formation (Doping):
  • Doping Magic: This step creates the heart of the solar cell - the p-n junction. Here's the magic:
    • P-type Doping: The wafers are selectively doped with boron atoms. Boron introduces "holes," which are the absence of electrons and act like positively charged carriers. This region becomes the p-type region.
    • N-type Doping: Phosphorus atoms are then introduced onto specific areas of the wafer. Phosphorus donates extra electrons, creating an n-type region.

The p-n junction is the foundation for the photovoltaic effect. Light hitting the cell creates an electric field across this junction, allowing electrons to flow and generate electricity.

  1. Antireflective Coating:
  • Light Trapping Champion: A thin layer of antireflective coating, like silicon nitride or titanium oxide, is applied to the front surface of the cell. This coating minimizes light reflection and maximizes light absorption within the silicon. Think of it like a special lens that helps trap more sunlight inside the cell.
  1. Metallization:
  • Electrical Collectors: Electrical contacts are applied to the front and back surfaces of the cell using techniques like screen printing or sputtering. These contacts, typically made of silver or aluminium paste, collect the generated current and allow it to flow out of the cell for use. Imagine them like tiny electrical highways that carry the electricity away.
  1. Cell Assembly:
  • Building the Powerhouse: Individual solar cells are interconnected electrically, often using thin metal strips called busbars or ribbons. These interconnected cells are then sandwiched between protective layers like encapsulant (ethylene vinyl acetate - EVA), tempered glass on the front, and a back sheet. The encapsulant protects the cells from moisture and mechanical damage, while the tempered glass provides strength and weather resistance. The final product is a solar panel, ready to convert sunlight into usable electricity.

This detailed breakdown provides a deeper understanding of the intricate steps involved in solar cell manufacturing. Each step plays a crucial role in transforming a simple silicon wafer into a powerful tool for harnessing the sun's energy.

Setting Up a Solar Cell Manufacturing Unit in India: Rules, Regulations, and Procedures

Establishing a solar cell manufacturing unit in India is a promising venture, but navigating the regulatory landscape can be complex. Here's an in-depth breakdown of the key legal requirements and procedures you'll encounter:

1. Business Registration and Permits:

  • Company Registration: Choose an appropriate business structure for your operation. You can register as a proprietorship for a smaller scale, or opt for a Limited Liability Partnership (LLP) or a company under the Companies Act, 2013 for larger ventures. Each structure offers varying degrees of liability protection and operational flexibility.
  • GST Registration: The Goods and Services Tax (GST) is a nationwide indirect tax levied on the supply of goods and services. Registering for GST is mandatory if your anticipated annual revenue exceeds the threshold limit set by the government. GST registration helps streamline tax compliance and facilitate business transactions.
  • Industrial License: Depending on the size and projected production capacity of your manufacturing unit, you might require an industrial license from the Department of Industrial Policy and Promotion (DIPP). The DIPP website provides a handy tool to determine if your proposed unit falls under the licensing ambit.
  • Factory License: As the major activity of manufacturing solar cells the unit must required factory license for such manufacturing activity.
  • BIS certificate: BIS certification will be required for manufacturing of solar cell as this will certify the safeguard to the public health, provides quality assurance and assures the product is not hazardous for human health.
  • ISO certification: As the ISO satisfy the customers faith in domestic and international market place, ISO certification is also required for solar cell manufacturing unit and products.

2. Environmental Clearances:

  • Pollution Control Board (PCB) Authorization: Operating a manufacturing facility necessitates obtaining a Consent to Establish (CTE) and Consent to Operate (CTO) from the State Pollution Control Board (SPCB) in your area. These clearances signify that your proposed manufacturing processes comply with established environmental regulations for air and water pollution control, hazardous waste management, and overall environmental impact. The SPCB will assess your application based on factors like the type and volume of pollutants generated, wastewater treatment plans, and solid waste disposal mechanisms.
  • E-Waste Management Authorization: Solar cell manufacturing often involves the use of electronic components. If your production process generates electronic waste (e-waste), you'll need authorization for handling and disposal from the Central Pollution Control Board (CPCB). The CPCB outlines specific guidelines for e-waste management, ensuring environmentally responsible disposal practices.

3. Additional Approvals:

  • No Objection Certificate (NOC) from Fire Department: Fire safety is paramount. Obtaining a No Objection Certificate (NOC) from the Fire Department in your area verifies that your facility adheres to fire safety regulations regarding building codes, electrical installations, firefighting equipment, and emergency evacuation plans.
  • Latest Tax Receipt: Furnish a receipt from the Municipal/Gram Panchayat for the land where your factory will be located. This demonstrates you've paid the necessary property taxes, ensuring you have the legal right to operate from that location.
  • Auditor Compliance Certificate: Certain government incentives for solar cell manufacturing might require an auditor compliance certificate regarding your fossil fuel utilization. This certifies your commitment to clean energy practices.
  • Approval from Chief Electrical Inspector: Ensure the safety and efficiency of your electrical installations by securing approval from the Chief Electrical Inspector of your state. They will inspect your electrical infrastructure to ensure compliance with relevant safety standards.
  • Clearance from Forest Department: If your facility setup involves any land use changes or requires acquiring forest land, you'll need clearance from the Forest Department. This ensures adherence to regulations protecting environmentally sensitive areas.

 

4. Power Evacuation Arrangement:

  • Permission from Electricity Discom: If your manufacturing unit plans to generate excess electricity, you'll need permission from the local electricity Distribution Company (Discom) for grid interconnection. This allows you to export surplus power to the grid, potentially generating additional revenue. Discoms will have specific technical requirements for grid interconnection, and obtaining their permission is crucial for a functional operation.

5. Land Conversion (if applicable):

  • Land Use Conversion: If you're converting agricultural land for your facility, you'll need to obtain land conversion permission from the relevant authorities. This process typically involves submitting an application and paying any conversion fees mandated by the state government.

6. Regulatory Compliance for PV Modules:

  • Mandatory Testing and Registration: The Ministry of New and Renewable Energy (MNRE) enforces the Approved List of Models and Manufacturers (ALMM) scheme. This program mandates that all solar photovoltaic (PV) modules manufactured or sold in India undergo rigorous testing and registration. This ensures product quality, consumer safety, and adherence to national solar energy standards.

The Indian government actively supports the development of domestic solar cell manufacturing to achieve energy security and reduce reliance on imports. Here are some key government schemes that can benefit your solar cell manufacturing plant setup:

Production Linked Incentive Scheme for the National Programme on High Efficiency Solar PV Modules:

  • This flagship scheme by the Ministry of New and Renewable Energy (MNRE) offers financial incentives to companies that set up giga-watt (GW) scale manufacturing capacity for high-efficiency solar PV modules.
  • The scheme provides a tiered incentive structure based on the efficiency of the manufactured modules.
  • This scheme aims to attract significant investments, promote technological advancements, and make India a global leader in high-efficiency solar cell manufacturing.

 

Modified Special Incentive Package Scheme (M-SIPS):

  • Although closed for new applications as of December 2018, the M-SIPS scheme by the Ministry of Electronics & Information Technology (MeitY) is still worth considering if you can leverage existing applications or similar future initiatives.
  • This scheme offered capital subsidy support for setting up new electronics manufacturing units, including solar cell production facilities.

Preference to 'Make in India' in Public Procurement:

  • The MNRE prioritizes domestically manufactured solar modules in government tenders and public procurement programs.
  • This policy incentivizes companies to set up manufacturing facilities in India and helps them secure a stable domestic market for their products.

Tax Benefits:

  • The government offers various tax benefits for solar cell manufacturers, including:
    • Exemption or concessional customs and excise duties on imports of capital goods.
    • Tax breaks on profits earned from solar cell manufacturing.
    • Accelerated depreciation benefits for plant and machinery.

Other Initiatives:

  • The government also supports research and development activities in solar cell technology through various institutions and funding programs.
  • Additionally, they organize skill development programs to create a skilled workforce for the solar sector.

By strategically leveraging these government schemes and staying informed about policy changes, you can significantly enhance the viability and competitiveness of your solar cell manufacturing venture in India.