Types of Solar Rooftop Plates - Working, Specifications, Capacity & Lifespan

        With the rise in demand for renewable energy, solar rooftop systems have become a widely adopted solution for both residential and institutional electricity needs. At the core of these systems are solar plates—commonly known as solar panels—which convert sunlight into electricity. The selection of the right solar panel type depends on efficiency, installation area, budget, and desired output.

Solar Rooftop Plates - Working, Specifications, Capacity & Lifespan

Working Principle of Solar Rooftop Plates -

    All solar panels work on the photovoltaic effect. When sunlight hits the surface of a solar cell, photons in the sunlight dislodge electrons in the silicon-based semiconductor material. These free electrons flow through an electric circuit, generating direct current (DC), which is later converted into alternating current (AC) via an inverter for use in homes or institutions.

Types of Solar Rooftop Panels (Plates)

1. Monocrystalline Solar Panels (Mono-Si)

Made from a single crystal structure of high-purity silicon, these panels are known for their sleek black appearance and high efficiency.

- Efficiency - 18% to 22%

- Temperature Coefficient - 0.3% to -0.5% per °C (lower is better)

- Power Output - 320W – 600W (per panel)

- Lifespan - 25–30 years

- Best For - Limited rooftop space, high-efficiency requirements

- Cost - Higher than other types, but provides better ROI over time

Advantages -

- High power output per square meter

- Better performance in low-light and high-heat environments

2. Polycrystalline Solar Panels (Poly-Si)

    These panels are speckled and have a bluish colour because they are made of many silicon pieces that have been melted and put into moulds.

- Efficiency - 15% to 17%

- Temperature Coefficient - ~ -0.4% per °C

- Power Output - 250W – 400W (per panel)

- Lifespan - 20–25 years

- Best For - Larger rooftops, budget-friendly installations

- Cost - Cheaper than monocrystalline

Advantages -

- Cost - effective for large-scale installations

- Stable performance under average sunlight

3. Thin-Film Solar Panels (TFSP) -

    These are made by depositing one or more layers of photovoltaic material on a substrate like glass, plastic, or metal. Amorphous silicon (a-Si) and cadmium telluride (CdTe) are common materials.

- Efficiency: 10% to 12% (can go up to 14% with advanced models)

- Temperature Coefficient - 0.2% to -0.3% per °C

- Power Output - 100W – 300W (per panel)

- Lifespan - 10–20 years

- Best For - Curved or non-traditional roofs, lightweight applications

- Cost - Medium to low

Advantages -

- Flexible and lightweight

- Better performance in shaded or partially sunlit conditions

4. Bifacial Solar Panels -

    These panels can absorb sunlight from both the front and rear surfaces, increasing overall energy yield, especially when installed on reflective surfaces (e.g., white rooftops).

- Efficiency - Up to 25%

- Power Output - 350W – 700W

- Lifespan - 25+ years

- Best For - High-reflectivity rooftops, institutional use

- Cost - Higher initial investment

Advantages -

- Generates more energy from the same area

- Ideal for government or commercial rooftops with higher demands

5. Half-Cut Cell Solar Panels -

    A variation of mono or polycrystalline panels where cells are cut into halves to reduce resistance and improve performance.

- Efficiency - 19% to 23%

- Power Output - 370W – 600W

- Lifespan - 25 years

- Best For - Areas with partial shading or high temperatures

- Cost -Slightly more than standard panels

Advantages -

- Less power loss due to shading

- Higher durability and energy output

Comparison Table -

Panel Type	Efficiency	Lifespan	Power Output	Cost	Best Use Case
Monocrystalline	18–22%	25–30 yrs	320–600W	High	Limited space, max output
Polycrystalline	15–17%	20–25 yrs	250–400W	Medium	Budget-friendly setups
Thin-Film	10–12%	10–20 yrs	100–300W	Low	Lightweight, flexible use
Bifacial	Up to 25%	25+ yrs	350–700W	High	Reflective rooftops
Half-Cut Cell	19–23%	25 yrs	370–600W	Medium	Shaded or hot climates

    Choosing the right type of solar rooftop plate involves understanding your roof’s area, orientation, budget, and power requirement. In Rajasthan’s sun-rich environment, monocrystalline or bifacial panels offer the best long-term value for government and institutional installations, while polycrystalline panels are ideal for cost-sensitive projects.

        Installing efficient solar panels not only lowers electricity bills but also contributes to environmental protection by reducing carbon emissions and promoting clean, renewable energy adoption.

Government Scheme - PM Surya-ghar Muft Bijlee Yojna, an initiative by the central government, aims for the installation of solar net metering for households, under which the government of India offers a subsidy. The scheme to promote renewable energy to cut much higher household bills and helps in the reduction in carbon emission.