PV Module: Solar Panel Technologies and Selection

Q: What is the difference between PERC, TOPCon and HJT modules?

All three are crystalline silicon cell designs. PERC adds a passivated rear layer and dominated production until about 2022. TOPCon adds a tunnel oxide passivating contact on n-type wafers. HJT layers thin amorphous silicon on crystalline silicon, giving low temperature losses and degradation.

Q: What is the typical warranty on a PV module?

Most manufacturers offer a 12 to 25 year product warranty and a 25 to 30 year linear power warranty. Power warranties usually guarantee around 98 to 99% output in year one, then a fixed yearly decline, ending roughly 80 to 89% at the end of term depending on technology.

Q: Do PV modules need ALMM listing in India?

Yes for most government-linked projects. MNRE's Approved List of Models and Manufacturers (ALMM) List-I covers modules, and listed products are required for government, subsidised, net-metered and open-access projects. Modules must also carry BIS registration under IS 14286 and IS/IEC 61730.

Q: What is module degradation?

Degradation is the gradual loss of output power over time. It includes initial light-induced degradation in the first months, then a slower linear rate, often around 0.4 to 0.55% per year for modern n-type modules. Energy yield models apply both rates across the project life.

Quick answer

A PV module (photovoltaic module) is a sealed, framed assembly of solar cells that converts sunlight into DC electricity. Crystalline silicon modules are design-qualified under IEC 61215 (IS 14286 in India) and safety-qualified under IEC 61730. Designers use module datasheet values such as Voc, Isc and temperature coefficients to size strings and inverters.

Quick Facts

Field	Detail
Term	PV Module / Solar Panel
Category	Solar Components
Standards	IEC 61215, IEC 61730, UL 1703, UL 61730, IS 14286
Typical Power	400-650 W (commercial-grade c-Si)
Efficiency	19-24%
Difficulty Level	Beginner

Module Anatomy

Power, voltage, and current values printed on a module’s nameplate are all measured at Standard Test Conditions, the physical layers below are what actually deliver that rated output in the field.

Glass cover (3.2 mm tempered), UV protection.
EVA encapsulant: adheres glass to cells.
PV cells: silicon wafers with conductive grid.
Back encapsulant: EVA or POE.
Back sheet (monofacial) or glass back (bifacial).
Aluminum frame: structural support.
Junction box: bypass diodes + MC4 connectors.

Cell Technologies (2024)

PERC (Passivated Emitter Rear Cell)

Dominant 2018-2022.
21-22% efficiency.
LID 1.5-2%.
Phasing out in favor of TOPCon.

TOPCon (Tunnel Oxide Passivated Contact)

Dominant 2023+.
22-23% efficiency.
Lower LID (<0.5%).
Better bifaciality (75-85%).
Improved high-temp behavior.

HJT (Heterojunction Technology)

Premium tier.
22-24% efficiency.
Lowest LID (<0.3%).
Best high-temp performance.
Highest cost (~5-10% premium over TOPCon).

Other (niche)

IBC (Interdigitated Back Contact): SunPower Maxeon, 22%.
Tandem perovskite: emerging, lab efficiency 30%+.
CdTe (First Solar): 18-19%, thin-film, low-temp benefit.

Form Factors

Form	Cell count	Module power (TOPCon, 2024)
60-cell full	60	380-420 W
72-cell full	72	460-510 W
60-cell half	120	410-450 W
72-cell half	144	540-580 W
Bifacial 72-cell	144	545-620 W
Large-format (210 mm)	110-135	600-660 W

Major Manufacturers (2024)

Brand	Country	Tier	Specialty
Longi	China	Tier 1	Volume leader, TOPCon
Jinko	China	Tier 1	TOPCon volume
Trina	China	Tier 1	Bifacial leader
Canadian Solar	Canada/China	Tier 1	US market focus
JA Solar	China	Tier 1	Diversified
Q CELLS	Korea/Germany	Tier 1	Premium residential
REC	Norway/Singapore	Tier 1	HJT
Adani	India	Tier 1	India market
Waaree	India	Tier 1	India market
Goldi Solar	India	Emerging	ALMM-listed

Permitting & Standards

NEC 690.4(B): All modules must be listed (UL 1703 or UL 61730).
IEC 61215: Crystalline module performance.
IEC 61730: Module safety.
UL 1703 / UL 61730: North America listing.
IS 14286: India PV module standard.
ALMM: India approved list for subsidized projects.

Key Takeaways

Modern PV modules are 400-650 W, 19-24% efficient, using PERC/TOPCon/HJT crystalline silicon.
TOPCon dominates 2024+ utility-scale; HJT premium for residential and high-temperature climates.
Bifacial modules add 5-25% rear-side gain in ground-mount installations.
Verify UL 1703/61730 (US) or IS 14286 (India) listing before specifying.
For Indian subsidized projects, confirm ALMM listing on the MNRE portal.

A module’s nameplate power and bifacial gain are only starting inputs, how they translate into an 8,760-hour energy forecast is covered in PV Yield Simulation Software: The Bankable Yield 5 (2026), which walks through the tools that turn cell-level specs into a bankable yield number.

On the structural side, the module weights and wind-exposed surface area referenced above (22-32 kg per panel, depending on glass-glass vs. glass-backsheet construction) are exactly what racking and foundation calculations have to absorb; see ASCE 7-22 Wind Load for Solar Rooftops, A Designer’s Reading for how that load path is sized.

For ground-mount arrays specifically, where bifacial modules do most of their rear-side gain, our Solar Ground Mount Design service covers the racking and tilt decisions that go with module selection.

Frequently Asked Questions

4 commonly searched questions about PV Module.

What is the difference between PERC, TOPCon and HJT modules?

All three are crystalline silicon cell designs. PERC adds a passivated rear layer and dominated production until about 2022. TOPCon adds a tunnel oxide passivating contact on n-type wafers. HJT layers thin amorphous silicon on crystalline silicon, giving low temperature losses and degradation.

What is the typical warranty on a PV module?

Most manufacturers offer a 12 to 25 year product warranty and a 25 to 30 year linear power warranty. Power warranties usually guarantee around 98 to 99% output in year one, then a fixed yearly decline, ending roughly 80 to 89% at the end of term depending on technology.

Do PV modules need ALMM listing in India?

Yes for most government-linked projects. MNRE's Approved List of Models and Manufacturers (ALMM) List-I covers modules, and listed products are required for government, subsidised, net-metered and open-access projects. Modules must also carry BIS registration under IS 14286 and IS/IEC 61730.

What is module degradation?

Degradation is the gradual loss of output power over time. It includes initial light-induced degradation in the first months, then a slower linear rate, often around 0.4 to 0.55% per year for modern n-type modules. Energy yield models apply both rates across the project life.

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