July 16, 2025

Choosing the right solar panels is one of the most important decisions when investing in a home solar PV system. The panels you choose will impact everything from output to the longevity and payback period.

With so many options on the market, it’s easy to get lost in a sea of efficiency ratings, warranties, and unfamiliar brand names. In this article, we will walk you through the main types of panels, bi-facial vs traditional mono-facial, and compare several leading brands to help you make a well-informed choice based on your home, budget, and energy goals.

1. Panel Types Overview

Mono-facial Panels (Traditional)

Traditional, mono-facial solar panels absorb daylight from one side only, and are usually installed flush to a sloped roof. These are still a common choice for residential solar installations.

Bi-Facial Panels

Bi-facial panels are designed to absorb daylight from both its front and rear surfaces. This allows them to harness light reflected from surfaces like gravel, grass, or rooftops, boosting their output without needing more space.

We recommend choosing bi-facial panels to ensure the ongoing performance and lifespan of your solar system.

Read this article to learn more about the advantages of bi-facial solar panels.

2. How We Compare Panels

When comparing solar panels, understanding key performance metrics is crucial to making an informed decision.

To provide a fair comparison, each panel is evaluated across these criteria:

1. Efficiency: The percentage of daylight converted into electricity

2. Temperature Coefficient: How output is affected by heat

3. Degradation Rate / Warranty: Long-term performance reliability

4. Cost per Watt: Value in terms of power output

5. Durability: Resistance to weather, hail, and wind

6. Installation Suitability: Whether it’s ideal for roof-mounted, flat, or ground-mounted systems

2.1 Efficiency: How Much Daylight Becomes Usable Electricity

Efficiency refers to how effectively a solar panel converts daylight into electricity. This matters especially when space is limited, the more efficient the panel, the more it can produce per square metre.

Choosing high-efficiency panels means you can generate more electricity from the same area.

It’s not just a technical spec, higher efficiency often leads to better system performance overall and can help maximise your return on investment.

2.2 Temperature Coefficient: Performance in Warm Conditions

The temperature coefficient tells you how much a panel’s performance drops as it gets hotter. Solar panels perform best in cooler conditions, and as temperatures rise, their output typically decreases.

This is expressed as a negative percentage per degree Celsius.

In Ireland, where extreme heat is rare, the temperature coefficient is less critical than in warmer climates. However, on warm summer days a lower temperature co-efficient helped to ensure consistent performance.

2.3 Degradation Rate and Warranty: Long-Term Energy Output

Over time, all solar panels gradually lose their ability to generate electricity, this is called the degradation rate. Premium panels will typically degrade between 0.3% and 0.5% per year, meaning they will still produce between 87% and 93% of their original output after 25 years.

Lower degradation rates mean more long-term value. Manufacturers usually back this up with a performance warranty, often promising a minimum 80%-90% output after 25 years.

In Ireland, where solar panel are rarely exposed to extreme temperatures, UV radiation, or dust, well-made panels can often outperform their stated warranties.

2.4 Cost per Watt: Understanding Value, Not Just Price

Cost per watt is a way to compare the value of different solar panels. It’s calculated by dividing the price of a panel by how much power it can produce (in watts).

For example, a more expensive panel may be better value if it produces significantly more electricity or has a longer lifespan.

While it may be tempting to go for the cheapest option, lower-cost panels sometimes have higher degradation rates or shorter warranties, which could cost longer in the long run due to maintenance, repair and the need for replacement.

In Ireland, where solar PV incentives and grants help to offset upfront costs, it’s worth weighing quality and long-term performance alongside price.

2.5 Durability: Withstanding Irish Weather

The Irish weather can be unpredictable. Strong winds, heavy rain, and occasional hail are all factors to consider.

A panel’s durability is usually certified through international standards such as IEC 61215, which tests for extreme weather conditions, including wind pressure and hail impact.

Look for panels with a high mechanical load rating and a proven track record in similar climates.

Panels with solid framing, tempered glass and a good IP (Ingress Protection) rating will typically handle the Irish weather with ease, ensuring they last for decades, performing without issue.

2.6 Installation Suitability: Matching Panels to Your Roof or Property

Not all solar panels are suitable for every type of installation. Some are better for pitched roofs, others for flat roofs or ground-mounted systems. Weight, dimensions, and mounting systems all play a role in determining whether a panel is a good fit.

For Irish homes with slate or tile roofs, lighter panels or specialised mounting systems may be needed. Panels with a higher wattage per square metre are ideal when roof space is limited.

Ground-mounted panels, often used in rural areas, offer more flexibility in size and orientation but require more land and groundwork.

Choosing a panel that suits your property layout is key to maximising energy output and installation lifespan.

4. What Is N-Type and Why Should You Care?

When looking at solar panel specs, you might come across the terms N-type and P-type, these refer to the type of silicon used inside the solar cells. Both types do the same job: converting daylight into electricity. But the way they’re built affects how well they perform, especially over time.

N-type panels use a more advanced type of silicon that resists impurities and sunlight-related damage better than traditional P-type panels. This makes them more efficient and longer-lasting.

For homeowners, the key benefit is simple: N-type panels produce more electricity for longer

5. Weather Protection: Understanding IP Ratings for Solar Panels

Solar PV panels should have a minimum rating of IP65, which means they are fully protected against dust and resistant to low-pressure water jets from any direction, ideal for Ireland’s frequent rain and wind.

IP stands for Ingress Protection, and it’s a measure of how well a device is sealed against dust and moisture. The first digit refers to protection against solids (like dust), and the second refers to protection against liquids (like rain or spray).

IP65: Dust-tight and resistant to water jets (minimum standard for solar panels)

IP66: Dust-tight and protected against stronger water jets

IP67: Dust-tight and can withstand temporary immersion in water

IP68: Dust-tight and suitable for continuous immersion (usually unnecessary for rooftop panels)

For Irish conditions, where panels face high rainfall, coastal winds, and occasional storms, IP65 or higher ensures the panel casing is built to last and won’t be compromised by the weather over time.

6. Comparison Summary Table

7. How to Pick the Right Panel for Your Home

Ask yourself:

• What is my budget?

• Is my roof south-facing or shaded?

• Do I have any reflective surface below the array (gravel, tiles, etc.)?

• Do I plan to stay in this home for 20+ years?

• Do I want a premium, long-term panel, or the best value upfront?

8. Final Recommendations

Best All-Round Panel for Residential Homes: Bauer Solar

Durable, efficient, and ideally suited for Irish rooftops. Bauer Solar offers the best product and performance warranties, protecting your investment. Their bi-facial design offers long-term gains even under cloud cover and diffuse light, making them a smart investment for long-term homeowners. Their robust design and excellent temperature performance also make them well-suited to the ever-changing Irish climate.

Best for High-Yield Installations: ATLAS Duo N-Type

Designed for maximum output in optimal conditions, the ATLAS Duo N-Type is ideal for ground-mounted systems with reflective surfaces or commercial rooftops. Built with high-efficiency N-type cells and a bifacial glass-glass structure, these panels excel when there’s room to optimise light capture from both the front and rear. Their robust design and excellent temperature performance also make them well-suited to larger-scale systems where long-term energy yield is the top priority.

Best Budget Option: LONGi

A proven performer with a wide range of models and strong value for money. LONGi is one of the world’s largest solar manufacturers, known for balancing cost and performance. Their panels use high-efficiency PERC technology and come with reliable warranties, making them a solid choice for homeowners looking to reduce upfront costs without compromising too much on performance. While they may not offer the premium specs of N-type panels, LONGi’s consistent quality and affordability make them ideal for budget-conscious installations.

9. Conclusion

No single solar panel is perfect for every home. The best option depends on your roof type, light conditions, budget, and how long you wish to get out of your solar system. While many panels offer similar core performance, factors like build quality, warranty, and long-term stability matter just as much.

If you’re seeking a balance between performance, reliability, and long-term value, especially for residential use, Bauer Solar is a strong contender. Its bi-facial design, solid efficiency, and glass-glass durability make it an ideal fit for Irish homes with varying light conditions.

Still unsure? Complete the form below to get in touch with a qualified installer who can assess your site and recommend the right solution.