CertainTeed Solstice Solar Panel 365W vs GAF Energy Timberline Solar ES
The CertainTeed Solstice Solar Panel 365W wins this comparison by a decisive margin. It leads in efficiency (19.9% vs 15%). For most residential installations, the CertainTeed Solstice Solar Panel 365W is the stronger choice.
Key Differences
- • CertainTeed Solstice Solar Panel 365W is rated at 365W while GAF Energy Timberline Solar ES is rated at 67W, a 298W difference.
- • CertainTeed Solstice Solar Panel 365W achieves 19.9% efficiency vs 15% for the other, a 4.9 percentage point gap.
- • GAF Energy Timberline Solar ES comes with a 25-year product warranty vs 10 years for the other.
- • CertainTeed Solstice Solar Panel 365W has a superior temperature coefficient of -0.36%/°C vs -0.41%/°C, retaining more power in hot climates.
- • CertainTeed Solstice Solar Panel 365W uses Monocrystalline PERC cells while GAF Energy Timberline Solar ES uses Monocrystalline cells, representing different technology generations.
Specifications Breakdown
Module Efficiency
The CertainTeed Solstice Solar Panel 365W achieves 19.9% module efficiency compared to GAF Energy Timberline Solar ES's 15%, meaning CertainTeed Solstice Solar Panel 365W converts 4.9 percentage points more sunlight into electricity per square meter. In practical terms, the CertainTeed Solstice Solar Panel 365W produces 199.2 watts per square meter of panel area while the GAF Energy Timberline Solar ES produces 148.2 W/m². For rooftop installations where space is limited, this efficiency gap determines how many kilowatts you can fit on your available roof area. Over a 25-year system life, even a small efficiency advantage compounds into meaningful additional energy production.
Power Output
The CertainTeed Solstice Solar Panel 365W delivers 365W per panel versus 67W for the GAF Energy Timberline Solar ES, a 298W difference per module. To build an 8 kW residential system, you would need 22 CertainTeed Solstice Solar Panel 365W panels or 120 GAF Energy Timberline Solar ES panels. Choosing the higher-wattage option saves 98 panels, reducing total racking hardware, wiring, and installation labor costs. Higher wattage per panel is particularly valuable for commercial-scale installations where panel count directly impacts balance-of-system costs.
Temperature Coefficient
The CertainTeed Solstice Solar Panel 365W has a temperature coefficient of -0.36%/°C versus -0.41%/°C for the GAF Energy Timberline Solar ES. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the CertainTeed Solstice Solar Panel 365W retains 92.8% of its rated power while the other retains 91.8%. While the numerical gap is modest, it still accumulates over decades of summer production, especially in southern latitudes with prolonged peak heat hours.
Warranty Coverage
The CertainTeed Solstice Solar Panel 365W is backed by a 10-year product warranty and 25-year performance guarantee, while the GAF Energy Timberline Solar ES offers 25-year product and 25-year performance coverage. The GAF Energy Timberline Solar ES provides 15 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (2% first year then 0.55%/year for CertainTeed Solstice Solar Panel 365W; 2.5% first year then 0.6%/year for GAF Energy Timberline Solar ES), after 25 years the CertainTeed Solstice Solar Panel 365W should retain approximately 84.8% of original output versus 83.1% for the GAF Energy Timberline Solar ES. This 1.7 percentage point gap in end-of-life output meaningfully impacts lifetime energy economics.
Physical Dimensions & Weight
The CertainTeed Solstice Solar Panel 365W measures 1755×1044×40mm and weighs 21.6 kg, while the GAF Energy Timberline Solar ES measures 1270×356×10mm at 5.2 kg. 1.83 m² of panel area for the CertainTeed Solstice Solar Panel 365W versus 0.45 m² for the GAF Energy Timberline Solar ES. The GAF Energy Timberline Solar ES is 16.4 kg lighter per panel, which reduces structural load requirements on the roof and makes handling easier during installation. For a 20-panel system, that is a total weight difference of 328 kg. The more compact GAF Energy Timberline Solar ES may be easier to fit on irregularly shaped or space-limited rooftops.
Specification Comparison
| Specification | CertainTeed Solstice Solar Panel 365W | GAF Energy Timberline Solar ES |
|---|---|---|
| Power | 365W | 67W |
| Efficiency | 19.9% | 15% |
| Power Density | 18.5 W/sq ft | 13.8 W/sq ft |
| Cell Type | Monocrystalline PERC | Monocrystalline |
| Bifacial | No | No |
| Weight | 21.6 kg | 5.2 kg |
| Temp Coefficient | -0.36%/°C | -0.41%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 10 years | 25 years |
| Performance Warranty | 25 years | 25 years |
| Degradation (Year 1) | 2% | 2.5% |
| Annual Degradation | 0.55% | 0.6% |
| Country | United States | United States |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: CertainTeed Solstice Solar Panel 365WThe CertainTeed Solstice Solar Panel 365W achieves 19.9% efficiency versus 15% — a 4.9 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 8.9 kW more total system capacity, or 41 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: CertainTeed Solstice Solar Panel 365WThe CertainTeed Solstice Solar Panel 365W has a better temperature coefficient of -0.36%/°C versus -0.41%/°C. On a 45°C summer day (20°C above STC), the winner retains 92.8% of rated power versus 91.8%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: GAF Energy Timberline Solar ESGAF Energy Timberline Solar ES leads with a 25-year product warranty versus 10 years. CertainTeed Solstice Solar Panel 365W degrades more slowly at 0.55% per year versus 0.6%. After 25 years, expect 84.8% vs 83.1% of original output for CertainTeed Solstice Solar Panel 365W and GAF Energy Timberline Solar ES respectively.
4. Power Output
Winner: CertainTeed Solstice Solar Panel 365WThe CertainTeed Solstice Solar Panel 365W delivers 365W versus 67W per panel — 298W more. For an 8 kW system, you need 22 panels with the higher-wattage option versus 120 panels, saving 98 panels and the associated racking and labor costs.
5. Cell Technology
Winner: GAF Energy Timberline Solar ESThe CertainTeed Solstice Solar Panel 365W uses Monocrystalline PERC: PERC (Passivated Emitter Rear Cell) is the current mainstream technology, offering good efficiency at the lowest manufacturing cost. The GAF Energy Timberline Solar ES uses Monocrystalline: Monocrystalline. Monocrystalline represents a newer generation technology with a longer performance runway as manufacturing matures.
CertainTeed Solstice Solar Panel 365W
The CertainTeed Solstice Solar Panel 365W is a conventional residential solar panel from CertainTeed (Saint-Gobain), using monocrystalline PERC half-cut cells. Designed to pair with CertainTeed roofing products for a coordinated roof-and-solar installation through certified roofing contractors.
Pros
- + Made in the USA by Saint-Gobain subsidiary
- + 10-year product warranty — strong for US-manufactured panel
- + Designed for seamless pairing with CertainTeed roofing
- + Half-cut PERC cells for partial shade resilience
- + Available through established roofing contractor network
Cons
- - 19.9% efficiency below current N-Type leaders
- - 365W output lower than modern 400W+ panels
- - Heavier at 21.6 kg than comparable wattage panels
- - Higher cost per watt than budget alternatives
- - Limited distribution outside CertainTeed roofing dealers
GAF Energy Timberline Solar ES
The GAF Energy Timberline Solar ES is the world's first nailable solar shingle — installed with a standard nail gun just like conventional roofing shingles. Each 67W unit integrates with GAF Timberline architectural shingles for a low-profile solar roof that any trained roofer can install. Wind rated to 130 mph. Efficiency not publicly disclosed — estimated at ~15%. Installed cost is $4.00-$5.50/W.
Pros
- + World's first nailable solar shingle
- + Installable by standard roofing crews — no solar specialists needed
- + 25-year dual warranty covering power and weatherization
- + 130 mph wind rating — suitable for hurricane zones
- + Class A fire rating
- + Low profile integrates seamlessly with GAF Timberline roofing
Cons
- - $4.00-$5.50/W installed — 2-3x cost of conventional panels
- - ~15% efficiency lower than rack-mounted panels
- - 67W per shingle requires many units for adequate system size
- - Higher operating temperature from flush roof mounting
- - Only available through GAF-certified installers
Choose CertainTeed Solstice Solar Panel 365W If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ You want fewer panels to reach your target system size, reducing racking and labor costs
- ✓ You live in a hot climate (Arizona, Texas, Florida) where heat performance matters
- ✓ You want maximum output retention over the system's 25-30 year lifespan
- ✓ Homeowners doing a combined roof replacement and solar installation through CertainTeed-certified contractors.
Choose GAF Energy Timberline Solar ES If...
- ✓ Long-term warranty protection is a top priority and you plan to stay in your home for 25+ years
- ✓ Homeowners wanting solar that installs like regular roofing, especially during a new roof or re-roof project, with broad installer availability.
Our Recommendation
The CertainTeed Solstice Solar Panel 365W is the decisive winner in this solar panel comparison, outperforming the GAF Energy Timberline Solar ES in 3 of 5 dimensions. Unless you have a specific requirement that the GAF Energy Timberline Solar ES uniquely addresses, the CertainTeed Solstice Solar Panel 365W is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, CertainTeed Solstice Solar Panel 365W or GAF Energy Timberline Solar ES?
The CertainTeed Solstice Solar Panel 365W wins this comparison by a decisive margin. It leads in efficiency (19.9% vs 15%). For most residential installations, the CertainTeed Solstice Solar Panel 365W is the stronger choice.
Which panel is more efficient, CertainTeed Solstice Solar Panel 365W or GAF Energy Timberline Solar ES?
The CertainTeed Solstice Solar Panel 365W at 19.9% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 4.9 percentage points translates to approximately 298W per panel under standard test conditions.
Which has a better warranty, CertainTeed Solstice Solar Panel 365W or GAF Energy Timberline Solar ES?
The CertainTeed Solstice Solar Panel 365W comes with a 10-year product warranty and 25-year performance guarantee. The GAF Energy Timberline Solar ES offers 25-year product and 25-year performance warranties. GAF Energy Timberline Solar ES provides 15 additional years of product coverage.
Which panel performs better in hot weather?
The CertainTeed Solstice Solar Panel 365W has a temperature coefficient of -0.36%/°C and the GAF Energy Timberline Solar ES is -0.41%/°C. CertainTeed Solstice Solar Panel 365W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many CertainTeed Solstice Solar Panel 365W vs GAF Energy Timberline Solar ES panels do I need for an 8 kW system?
For an 8 kW system: you need 22 CertainTeed Solstice Solar Panel 365W panels (365W each) or 120 GAF Energy Timberline Solar ES panels (67W each). The CertainTeed Solstice Solar Panel 365W requires fewer panels, saving on racking hardware and installation labor.
Related Resources
Last updated: February 2026