Choosing the Best Solar Panels in 2025: A Comprehensive Guide

Updated February 2025

Selecting the best solar panels for your system is crucial for maximising your return on investment. With solar technology advancing rapidly, understanding which panel suits your needs best can be challenging. This guide explores ten of the top solar panels available in 2025, providing key insights into their efficiency, performance, and suitability for different installation types.

Quick Summary

For those looking for a quick decision, here are the top recommendations based on installation type and key considerations:

• Best for Pitched Roof Installations: AIKO NeoStar 2 or NeoStar 3
• Best for Ground-Mounted or Flat Roof Systems: Eurener NEXA 500W (bifacial) or AIKO Comet 1N (jumbo panel)
• Best for Shaded Roofs: REC Alpha RX (better shading tolerance with four bypass diodes)
• Best for In-Roof Installations: AIKO NeoStar 2 or NeoStar 3 (superior temperature coefficient)
• Most Ethically Manufactured Panel: DMEGC (100% green production) or Eurener (recycled materials, ESG focus)
• Best Warranty Coverage: Eurener NEXA 500W (30-year product warranty when installed by a certified partner)

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1- What to Look for in a Solar Panel

1.1 Standard vs. Jumbo Panels
1.2 Solar Panel Efficiency
1.3 N-Type vs. P-Type Semiconductors
1.4 Temperature Coefficient
1.5 Warranty Considerations

2. Detailed Breakdown of Each Panel’s Advantages and Disadvantages

2.1 AIKO NeoStar 2 & 3
2.2 Eurener NEXA 500W
2.3 REC Alpha RX
2.4 JA Solar 440W
2.5 DMEGC 450W
2.6 SunPower Maxeon P7
2.7 AIKO Comet 1N (Jumbo Panel)
2.8 LONGi Hi-Mo X6 Explorer (Jumbo Panel)
2.9 DMEGC 585W (Jumbo Panel)

3. Best Panels for Each Situation

3.1 Best for Pitched Roof Installations
3.2 Best for Ground-Mounted or Flat Roof Systems
3.3 Best for Shaded Roofs
3.4 Best for In-Roof Installations
3.5 Best for Ethical Manufacturing

Conclusion

1. What to Look for in a Solar Panel

1.1 Standard vs. Jumbo Panels

The first consideration when choosing a solar panel is its size. Standard panels are commonly used for residential installations, while jumbo panels can optimise roof space, particularly on larger or commercial installations. For example, the 625W AIKO Comet 1N is a jumbo panel designed to maximise generation per square metre, making it ideal for larger projects.

It's important to note that jumbo panels are primarily designed for commercial installations, and some models may not be MCS certified, which is required for certain domestic solar installations in the UK. Always check certification before selecting a jumbo panel for residential use.

1.2 Solar Panel Efficiency

Efficiency is a key metric that determines how much power a panel can generate per square metre. The most advanced panels now reach efficiencies of 23% to 24%, such as the upcoming AIKO NeoStar 3, which is expected to hit 24.3% efficiency.

With the NeoStar 3’s impending release, many homeowners might wonder if it’s worth waiting for this model. While this panel offers incremental improvements over the NeoStar 2, delaying installation means missing out on potential energy savings and financial returns that would accumulate over time. Given that solar returns are tax-free, investing sooner rather than later often makes better financial sense.

1.3 N-Type vs. P-Type Semiconductors

N-type semiconductor panels are preferable to P-type because they suffer less from light-induced degradation and provide better long-term performance. Panels like the AIKO NeoStar 2 and REC Alpha RX use N-type silicon to improve longevity and output.

1.4 Temperature Coefficient

Solar panels perform better at lower temperatures. The temperature coefficient tells you how much efficiency drops as the panel heats up. A high-quality panel will have a coefficient of -0.3% per degree Celsius or better, with leading models like the REC Alpha RX achieving -0.24% per degree Celsius.

This factor is particularly critical for in-roof solar installations, where panels tend to operate at higher temperatures due to reduced airflow beneath them. A panel with a lower temperature coefficient, such as AIKO NeoStar 2 or 3, will help mitigate performance losses in these conditions.

1.5 Warranty Considerations

Solar panels come with two types of warranties:

• Performance Warranty: Ensures a minimum power output over 25-30 years.
• Product Warranty: Covers defects or failures, typically ranging from 15 to 30 years.

The Eurener NEXA 500W provides an industry-leading 30-year product warranty when installed by a Eurener premium partner.

2. Detailed Breakdown of Each Panel’s Advantages and Disadvantages

2.1 AIKO NeoStar 2 & 3

• Pros: High efficiency (22.8%-24.3%), excellent temperature coefficient (-0.26%), sleek black design, reliable long-term performance
• Cons: Slightly more expensive than budget panels, limited bifacial capabilities, upcoming NeoStar 3 may create decision delays
• Best for: Standard pitched roof installations, in-roof systems, residential solar systems prioritising aesthetics and efficiency

2.2 Eurener NEXA 500W

• Pros: 30-year product warranty (when installed by a certified partner), high bifacial output, strong ESG credentials, high durability
• Cons: Slightly more expensive, certification requirement for full warranty coverage, bifacial gains depend on installation conditions
• Best for: Ground-mounted and flat roof systems where bifacial panels can take advantage of reflected light

2.3 REC Alpha RX

• Pros: Four bypass diodes (superior shading resistance), industry-leading temperature coefficient (-0.24%), durable build quality, high voltage design beneficial for smaller string lengths
• Cons: Higher price point, bifacial technology may not provide significant benefits for on-roof installations
• Best for: Shaded installations, systems with fewer panels but higher voltage requirements

2.4 JA Solar 440W

• Pros: Affordable, widely available, solid efficiency (22%), long warranty (25 years product, 30 years performance)
• Cons: Lower efficiency than premium models, standard temperature coefficient (-0.3%)
• Best for: Budget-conscious buyers looking for a reliable panel

2.5 DMEGC 450W

• Pros: Cost-effective, good efficiency (22.5%), 25-year product warranty
• Cons: Not as high efficiency as premium panels, slightly higher degradation over time
• Best for: Budget installations where cost-effectiveness is key

2.6 SunPower Maxeon P7

• Pros: Strong build quality, high reliability, 30-year warranty, well-established brand reputation
• Cons: High cost compared to competing panels, no longer the most efficient panel on the market
• Best for: Those prioritising long-term reliability and warranty coverage over cost-effectiveness

2.7 AIKO Comet 1N (Jumbo Panel)

• Pros: 625W output, highly efficient use of roof space, ideal for large-scale commercial installations
• Cons: Not always MCS certified for domestic use, heavier weight requires strong racking systems
• Best for: Large commercial and industrial projects

2.8 LONGi Hi-Mo X6 Explorer (Jumbo Panel)

• Pros: Strong efficiency (22.3%), cost-effective, widely available
• Cons: P-type semiconductor, slightly higher degradation
• Best for: Those looking for an affordable, efficient panel

2.9 DMEGC 585W (Jumbo Panel)

• Pros: High power output, good efficiency (22.6%), bifacial capabilities
• Cons: Heavier weight, not ideal for smaller roofs
• Best for: Ground-mounted or large-scale roof installations

3. Best Panels for Each Situation

3.1 Best for Pitched Roof Installations

• AIKO NeoStar 2 or NeoStar 3: Offers the best balance of efficiency, cost, and long-term durability. The sleek black design blends well with residential aesthetics.
• Eurener NEXA 500W: A premium choice with an extended 30-year warranty, ideal for those prioritising longevity.

3.2 Best for Ground-Mounted or Flat Roof Systems

• Eurener NEXA 500W or REC Alpha RX: Bifacial panels that capture additional energy from reflected light, increasing system efficiency.
• AIKO Comet 1N: A jumbo panel that maximises output for large installations.

3.3 Best for Shaded Roofs

• REC Alpha RX: Features four bypass diodes to maintain efficiency in partially shaded environments, significantly outperforming standard panels.

3.4 Best for In-Roof Installations

• AIKO NeoStar 2 or NeoStar 3: Lower temperature coefficient reduces heat-related efficiency losses, making them ideal for in-roof mounting systems.

3.5 Best for Ethical Manufacturing

• DMEGC: 100% green production and high sustainability credentials.
• Eurener: Uses recycled materials and strong ESG transparency.
• AIKO: Winner of a 2024 ESG Transparency Award for responsible manufacturing.
• JA Solar: Fully traceable supply chain ensuring ethical production.

Conclusion

Choosing the right solar panel depends on your specific installation type, budget, and energy needs. AIKO NeoStar 2 and 3 remain strong all-around options, while Eurener NEXA 500W excels in ground-mounted setups due to its bifacial capabilities. REC Alpha RX is the best for shaded conditions, and AIKO Comet 1N is ideal for large commercial projects.

Balancing efficiency, cost, durability, and warranty coverage is key to making the best decision. Consulting a trusted solar installer can refine your choices to maximise your return on investment.