Solar Panel Technologies- 2025

Below, we outline the key solar panel technologies considered in this study

Bifacial Glass–Glass (TOPCon / HJT)

Bifacial glass–glass modules use n-type Tunnel Oxide Passivated Contact ( TOPCon) or Heterojunction (HJT) cells laminated between two sheets of glass and produce power from both the front and rear sides. Typical commercial front-side efficiencies are around 22–23.5% , with rear-side gains adding approximately 5–30% extra annual energy yield in suitable sites [1–4].

Advantages:

• Higher energy yield: rear-side gains can increase annual production by about 5–30% compared with monofacial modules in high-albedo (reflective) sites [1, 2].
• Durable glass–glass construction: reduced moisture ingress and mechanical stress enable long lifetimes (> 30 years ) and low degradation rates [1, 13, 14].
• High front-side efficiency: commercial bifacial TOPCon/HJT modules commonly reach 22–23.5% efficiency [2–4].

Disadvantages:

• Higher weight: dual glass significantly increases module mass, which can challenge some rooftop and tracker designs [13, 14].
• Site-dependent benefit: limited rear irradiance (dark ground, dense row spacing) strongly reduces the bifacial gain [1, 2].
• Slight cost premium and design complexity require more detailed reflective power, spacing and mounting optimization than monofacial systems.

Glass–Glass Monofacial

Glass–glass monofacial modules retain the dual-glass laminate but generate electricity only from the front. They focus on robustness and low degradation, typically using high-efficiency TOPCon or HJT cells with commercial module efficiencies of about 21–23% [3, 4, 13, 14].

Advantages:

• Enhanced reliability: dual glass improves resistance to moisture, UV and mechanical loads, reducing long-term degradation [13–15].
• Long warranties: many products carry 30-year performance guarantees with around 0.25–0.4%/year degradation [13, 14].
• Good pairing with n-type cells supports long-lived TOPCon/HJT designs for premium rooftops and commercial systems [3, 4].

Disadvantages:

• Higher weight: similar mass penalty to bifacial glass–glass, which may exceed allowable roof loads on older buildings [13].
• No bifacial gain: customers pay a small glass–glass premium without rear-side power generation.
• Slight capital expenditure (CAPEX) premium: meaning the cost per watt is slightly higher than the bifacial module, and later the cost gap is narrowing [13].

Note:  Glass–glass refers to the module's construction (glass on both sides), whereas bifacial refers to the cells' ability to harvest light from both the front and rear. Many bifacial modules use a glass–glass design, but not all glass–glass modules are necessarily bifacial.

Perovskite–Silicon Tandem Panels

Perovskite–silicon tandem panels stack a wide-bandgap perovskite top cell on a silicon bottom cell to surpass the single-junction efficiency limit. Early commercial and pilot modules achieve roughly 23–25% efficiency, with record panels around 26–27% [2, 6–8], [16].

Advantages:

• Very high efficiency potential: tandem modules already reach about 25% , and cell records approach 30% [2, 6–8].
• Higher power density: roughly 20% more power per square meter compared with typical 21–23% silicon modules, reducing area and balance of system (BOS) costs [2, 6–8] .
• Thin and design-flexible: perovskite layers can be very thin and potentially colored or semi-transparent, enabling advanced Building Intergrated Photovoltaics (BIPV) concepts [8].

Disadvantages:

• Stability and lifetime not yet proven, current tandems target shorter (~ 10–20 years ) lifetimes than mature silicon modules [2, 8].
• Lead and encapsulation concerns: most high-efficiency perovskites use lead, requiring robust encapsulation and end-of-life management [8].
• High cost and limited availability: pilot-scale production keeps prices well above mainstream silicon, often more than 2–3× in €/W terms [2, 6–8].

Shingle Modules

Shingled modules cut cells into overlapping strips connected with conductive adhesive, eliminating front busbars and increasing active area. Commercial shingled modules typically reach about 20.5–22% ; premium variants can approach 23% [2, 10, 15].

Advantages:

• Higher power density: overlapping strips reduce inactive areas and busbar shading, improving light absorption and thereby module efficiency [10, 15].
• Better shade tolerance: many small parallel strips maintain power output when part of the panel is shaded [10, 15].
• Clean aesthetics: uniform, often all-black appearance is attractive for residential roofs [15].

Disadvantages:

• More demanding manufacturing: laser cutting and adhesive application add cost and potential failure modes [10].
• Edge and adhesive degradation risks: Poor process control can lead to long-term performance loss [10].
• Still a niche versus half-cut: half-cut, multi-busbar modules remain cheaper and more common in volume markets.

Flexible Thin-Film (CIGS / Perovskite)

Flexible thin-film laminates use Copper-Indium-Gallium-Selenide (CIGS) or perovskite absorbers on polymer, metal foil or ultra-thin glass substrates. Commercial flexible CIGS modules typically achieve  efficiencies of about  15–18% and the  weight can be as low as 3 kg/m² ; lab cells and tandems have reached even higher values ​​[9–11].

Advantages:

• Ultra-light and flexible: ideal for weak roofs, vehicle bodies, tents, curved façades and portable devices [9–11].
• Competitive thin-film efficiencies: flexible CIGS records around 18.7% , and flexible perovskite–CIGS tandems have exceeded 18–20% in mini-modules [9, 10].
• New application spaces: enable PV where rigid glass modules are too heavy or cannot conform to the surface [9–11].

Disadvantages:

• Lower efficiency than rigid n-type silicon: Commercial flexible modules (often  10–18% ) lag behind modern rigid panels ( 21–24% ) [11].
• Higher cost per watt: Because these panels are made in smaller quantities and for special uses, they can cost several times more per watt than standard silicon panels [11].
• Durability challenges: bending, moisture and perovskite stability demand advanced barrier and encapsulation solutions [8–11].

Multi-Busbar ( MBB) Tiling Ribbon Panels

MBB tiling ribbon panels combine multi-busbar (MBB) interconnection with tiling ribbon, which eliminates gaps between cells by slightly overlapping or tightly butting the cell edges. In commercial n-type products, typical module efficiencies are around 21–22.5% for standard formats [2, 9, 13–15].

Advantages:

• Higher module efficiency: eliminating cell gaps and using many thin busbars increases active area and can boost panel power by about 2–4% compared with conventional ribbon layouts using the same cells [2, 3, 9, 13–15].
• Reduced resistive and optical losses: multi-busbar layouts shorten current paths and reduce shading; MBB can absorb roughly 0.3–0.5% more light and cut resistive losses by 30–50% [1, 4, 5, 15].
• Lower silver consumption and mechanical robustness: many thin wires and tiling help distribute stress, reduce micro-crack losses and lower silver paste use per watt [2, 4, 13–15].

Disadvantages:

• More complex stringing and layup tiling ribbon and dense MBB wiring require precise alignment and process control, raising manufacturing complexity [9, 13–15].
• Potential edge-related reliability issues, close or overlapping cell edges, can be sensitive to thermal cycling and mechanical stress if encapsulation is poor [9, 13].
• Moderate cost premium versus simple 5BB half-cut designs, although gains in efficiency and lower silver usage offset part of the extra cost [2, 4, 13–15].

Solar Panel Comparison

Technology	Explanation	Commercial Efficiency	Structural Notes	Cost Level
Bifacial Glass–Glass (TOPCon/HJT)	Captures sunlight from both sides; Boosts annual energy yield;	~22–23.5%.	Glass–glass laminate with bifacial TOPCon/HJT cells.	High-efficiency price band (~0.11–0.13 €/Wp)
Glass–Glass Monofacial	Strong durability; Front-side generation only; long lifetime	~21–23%.	Dual-glass construction improves moisture, UV and mechanical resistance.	Mainstream to slightly higher (~0.09–0.12 €/Wp)
Perovskite–Silicon Tandem Panels	Designed to exceed single-junction silicon limits; Targets maximum power density per m²	~23–25%.	Perovskite top cell laminated over silicon.	Strong premium pricing (often >2–3x mainstream €/W)
Shingle Modules	Reduces inactive and shaded areas;	~20.5–22%.	Overlapping cell strips joined with conductive adhesive	Slightly above standard module cost
Flexible Thin-Film (CIGS/Perovskite)	Flexible; Very lightweight; Good fit for curved or irregular surfaces	~15–18%.	Ultra-light, bendable structures;	Specialty high-€/W products;
MBB Tiling Ribbon Panels	Multi-busbar distribute current; Tiling ribbon removes gaps between cells; Raises module power without changing cell technology	~21–22.5%.	Half-cut or full cells with many thin busbars; high energy density.	Upper mainstream to high-efficiency tier.

Conclusion

In 2025, solar panel technology is moving decisively towards higher efficiency, longer lifetimes and more specialized applications. Bifacial(TOPCon/HJT), glass–glass, perovskite–silicon tandems and MBB tiling ribbon modules push commercial efficiencies above conventional p-type designs, while shingled and flexible thin-film panels unlock new formats for rooftops and lightweight structures. Although some of these technologies still carry a cost or reliability premium, ongoing scale-up and process optimization are expected to narrow the gap. Overall, the current generation of PV modules provides more energy per square meter, better long-term stability and greater design flexibility, reinforcing solar power as a core pillar of future low-carbon energy systems.

References

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3. TaiyangNews. (2024). New Solar Modules Overview 2024.

4. TaiyangNews. (2023). Heterojunction Solar Technology - 2023 Edition.

5. Reuters. (2025). Trina Solar sets world record for solar technology.

6. Fraunhofer ISE. (2024). Oxford PV and Fraunhofer ISE develop full-sized tandem PV module with record efficiency of 25 percent.

7. Largue, P. (2024). Oxford PV achieves 25% efficiency record for solar panels. Enlit World.

8. Peplow, M. (2023). A new kind of solar cell is coming: Is it the future of green energy? Nature.

9. SNEC PV / Solar RRL. (2023). Four-terminal flexible perovskite–CIGS tandem mini-module with 18.4% efficiency.

10. Innovations-Report. (2025). Record efficiency of 18.7 percent flexible CIGS solar cells.

11. ETIP PV. (Roadmap). Thin-film (non-perovskite) PV modules – Roadmap 3.

12. Schachinger, M. (2024–2025). PV module price index and European wholesale prices.

13. PV-Tech. (2020). Tiger Module Technology White Paper (multi-busbar + tiling ribbon).

14. Sunterra Solar. (2022). Tiling Ribbon Technology (TR) explainer.

15. Terli / Sunevo Solar. (2024–2025). Multi-busbar (MBB) solar cell and panel design notes.

16.  EurekAlert: News release 2020