Choosing Solar Panels for Your Factory: Technology Comparison Guide UK 2025
A comprehensive comparison of solar panel technologies for UK industrial applications. Learn which panel type, efficiency rating, and inverter configuration delivers the best return on investment for your factory.
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Panel Technologies
Decision Factors
Introduction: Why Technology Choice Matters
Selecting the right solar panels for factories involves more than comparing price tags. The technology you choose affects how much electricity you generate, how long your system lasts, how well it performs in UK weather conditions, and ultimately your return on investment over 25+ years.
UK factories face unique challenges: limited daylight hours, frequent cloud cover, maritime climate, and often restricted roof space shared with HVAC equipment. This guide helps you navigate these factors to select the optimal technology for your specific situation.
Key Decision Factors for Factory Solar
- Available roof space: Less space requires higher efficiency panels
- Roof load capacity: Lightweight options for older buildings
- Budget constraints: Premium vs. value options
- Shading issues: Determines inverter configuration
- Aesthetic requirements: All-black vs. standard appearance
Monocrystalline Solar Panels
Monocrystalline panels dominate the UK commercial solar market, and for good reason. Made from single-crystal silicon, they offer the highest efficiency and best performance in the low-light conditions typical of British weather.
Monocrystalline Panel Specifications
Technical Characteristics
- Efficiency: 20-23%
- Temperature coefficient: -0.3% to -0.4%/C
- Degradation rate: 0.3-0.5% per year
- Lifespan: 25-30+ years
- Weight: 18-22 kg per panel
Cost & Warranty
- Cost: GBP 180-280 per panel (400-450W)
- Product warranty: 12-25 years
- Performance warranty: 25-30 years
- Guaranteed output at year 25: 85-87%
Advantages for Factory Applications
- Maximum output per square metre: Generate more power from limited roof space
- Superior low-light performance: Better output on cloudy UK days
- Lower degradation: Maintain higher output over 25+ year lifespan
- Aesthetic uniformity: Clean, professional appearance on visible roofs
- Premium warranties: Longer coverage from established manufacturers
PERC vs. TOPCon vs. HJT Technology
Within the monocrystalline category, several cell technologies compete for the commercial market:
| Technology | Efficiency | Cost Premium | Best For |
|---|---|---|---|
| PERC | 20-21% | Baseline | Budget-conscious projects |
| TOPCon | 21-22.5% | +5-10% | Optimal value/performance |
| HJT | 22-23% | +15-25% | Premium installations |
| IBC (Interdigitated Back Contact) | 22-24% | +30-40% | Space-constrained sites |
Our Recommendation
For most UK factory installations, TOPCon monocrystalline panels offer the best balance of efficiency, cost, and long-term value. The small premium over PERC technology delivers measurably better performance in low-light conditions typical of British climate.
Polycrystalline Solar Panels
Polycrystalline panels, recognisable by their blue, speckled appearance, were once the go-to choice for commercial installations. Made from multiple silicon crystals, they cost less to manufacture but sacrifice some efficiency.
Polycrystalline Panel Specifications
Technical Characteristics
- Efficiency: 16-18%
- Temperature coefficient: -0.4% to -0.5%/C
- Degradation rate: 0.5-0.7% per year
- Lifespan: 20-25 years
- Weight: 18-22 kg per panel
Cost & Warranty
- Cost: GBP 120-180 per panel (330-380W)
- Product warranty: 10-12 years
- Performance warranty: 25 years
- Guaranteed output at year 25: 80-82%
When Polycrystalline Makes Sense
- Large roof areas: When space isn't constrained, lower cost per watt matters more than efficiency
- Budget-limited projects: Get more kilowatts installed for the same investment
- Non-visible roofs: Aesthetic appearance less important
- Short ownership horizon: If selling the property within 10 years
Market Reality in 2025
The price gap between polycrystalline and monocrystalline panels has narrowed significantly. In many cases, the higher yield from monocrystalline panels over their lifetime now delivers better overall ROI despite the higher upfront cost. We recommend obtaining quotes for both technologies to compare lifecycle economics.
Thin-Film Solar Technology
Thin-film panels deposit photovoltaic material onto substrates in ultra-thin layers. While less common for factory installations, they offer unique advantages for specific applications.
Types of Thin-Film Technology
CdTe (Cadmium Telluride)
- Efficiency: 18-19%
- Best low-light performance
- Lowest carbon footprint to manufacture
- First Solar dominant manufacturer
CIGS
- Efficiency: 13-15%
- Flexible applications possible
- Good shade tolerance
- Limited commercial availability
Amorphous Silicon (a-Si)
- Efficiency: 6-8%
- Lowest cost
- Building-integrated applications
- Rarely used for commercial
Factory Applications for Thin-Film
- Lightweight requirements: Half the weight of crystalline panels suits weak roof structures
- Curved surfaces: Flexible options conform to barrel vault or curved roofs
- Very large installations: First Solar CdTe panels popular for utility-scale projects
- Hot climates: Better temperature coefficient (less relevant for UK)
Bifacial Solar Panels
Bifacial panels capture sunlight from both front and rear surfaces. While they cost more, they generate additional energy from light reflected off the surface below.
Bifacial Performance Gains
| Surface Below Panels | Albedo | Extra Generation |
|---|---|---|
| White TPO membrane | 80% | 10-15% |
| Light gravel/concrete | 40-50% | 5-10% |
| Dark bitumen roofing | 10-15% | 2-5% |
| Green roof | 20-25% | 3-6% |
When Bifacial Panels Make Sense
- White or light-coloured roofs: Maximises reflected light capture
- Elevated mounting systems: Greater gap between panels and roof
- East-West orientation: Captures reflected morning and afternoon light
- Snow-prone locations: Reflected light from snow cover
Factory Consideration
Many UK factories have white single-ply membrane roofs which are ideal for bifacial panels. If your factory has this roofing type, the 10-15% extra generation typically justifies the 10-15% cost premium for bifacial panels.
Efficiency Comparison: What the Numbers Mean
Panel efficiency measures how much of the sunlight hitting the panel converts to electricity. For factory installations, efficiency directly impacts how much generation capacity you can fit on your available roof space.
| Technology | Efficiency Range | Watts/m2 | kWh/kWp/year (UK avg) |
|---|---|---|---|
| Premium Mono (IBC/HJT) | 22-24% | 220-240 | 950-1,000 |
| Standard Mono (TOPCon) | 21-22% | 210-220 | 920-960 |
| Entry Mono (PERC) | 19-21% | 190-210 | 880-920 |
| Polycrystalline | 16-18% | 160-180 | 840-880 |
| Thin-Film (CdTe) | 18-19% | 180-190 | 900-940 |
Real-World Impact Example
Case Study: 2,000m2 Factory Roof
Usable area for panels: 1,400m2 (after setbacks, obstacles, access routes)
Polycrystalline (17%)
- System size: 238 kWp
- Annual yield: 202,300 kWh
- System cost: GBP 190,000
TOPCon Mono (21.5%)
- System size: 301 kWp
- Annual yield: 277,000 kWh
- System cost: GBP 241,000
Premium HJT (23%)
- System size: 322 kWp
- Annual yield: 306,000 kWh
- System cost: GBP 290,000
At 28p/kWh, the TOPCon system saves GBP 21,000 more annually than polycrystalline despite costing GBP 51,000 more upfront. Extra investment recovered in under 2.5 years.
Cost Analysis: Price vs. Value
Panel costs represent only 25-35% of total system cost. However, selecting the right panels affects overall system value through efficiency, degradation rates, and warranty coverage.
| Category | GBP/Wp (Panel Only) | GBP/Wp (Installed) | 25-Year LCOE |
|---|---|---|---|
| Budget Polycrystalline | 0.18-0.22 | 0.65-0.75 | 4.2-4.8p/kWh |
| Standard PERC Mono | 0.22-0.28 | 0.70-0.85 | 3.8-4.2p/kWh |
| TOPCon Mono | 0.26-0.32 | 0.75-0.90 | 3.5-4.0p/kWh |
| Premium HJT/IBC | 0.35-0.50 | 0.90-1.10 | 3.4-4.0p/kWh |
| Thin-Film CdTe | 0.20-0.26 | 0.68-0.80 | 3.6-4.2p/kWh |
LCOE (Levelised Cost of Energy) accounts for degradation, maintenance, and inverter replacements over the system lifetime. Better panels often deliver lower LCOE despite higher upfront costs.
Inverter Technology Options
Inverters convert DC electricity from panels to AC for use in your factory. The right inverter configuration maximises system output and provides monitoring capabilities.
String Inverters
Most common for commercial installations. Multiple panels connect in series strings to central inverters.
Pros:
- Lower cost per watt
- Easier maintenance (ground-level access)
- Proven reliability
- 10-15 year warranties
Cons:
- Shading affects entire string
- Less granular monitoring
- Single point of failure per string
Best for: Unshaded roofs, simple layouts
String + Power Optimisers
DC-DC converters at each panel maximise individual panel output before string inverter.
Pros:
- Panel-level MPPT
- Shading impact reduced
- Individual panel monitoring
- Rapid shutdown compliance
Cons:
- 10-20% cost premium
- More components to fail
- Roof-level maintenance
Best for: Partial shading, complex roofs
Microinverters
Complete DC-to-AC conversion at each panel. No central inverter required.
Pros:
- Maximum per-panel optimisation
- No single point of failure
- Detailed monitoring
- 25-year warranties available
Cons:
- Highest cost option
- More components on roof
- Not ideal for large systems
Best for: Heavy shading, multiple orientations
Central Inverters
Large-scale inverters for systems above 500kW. Multiple strings connect to single unit.
Pros:
- Lowest cost per watt
- High efficiency at scale
- Simplified architecture
- Industrial-grade durability
Cons:
- Requires dedicated space
- Single point of failure
- No panel-level optimisation
Best for: Large factories, ground-mount arrays
Recommended Inverter Brands for UK Commercial
| Brand | Type | Warranty | UK Support |
|---|---|---|---|
| SolarEdge | String + Optimisers | 12-25 years | Excellent |
| SMA | String / Central | 5-10 years (extendable) | Excellent |
| Huawei | String + Optimisers | 10-15 years | Good |
| Fronius | String | 5-10 years (extendable) | Excellent |
| Enphase | Microinverters | 25 years | Good |
Our Technology Recommendations
Based on UK climate conditions, factory requirements, and 2025 market pricing, here are our recommendations for different scenarios:
Best Overall: TOPCon Monocrystalline + String Inverters with Optimisers
Optimal balance of efficiency, cost, and long-term value for most UK factory installations.
- Panel brands: Longi, JA Solar, Trina Solar, Canadian Solar
- Inverter: SolarEdge or Huawei with power optimisers
- Installed cost: GBP 0.75-0.85/Wp
- Expected payback: 4-6 years
Premium Choice: HJT or IBC Monocrystalline + Microinverters
Maximum generation and longevity for space-constrained or architecturally sensitive installations.
- Panel brands: SunPower, REC Alpha, Panasonic
- Inverter: Enphase IQ8 microinverters
- Installed cost: GBP 0.95-1.15/Wp
- Expected payback: 5-7 years
Budget Option: PERC Monocrystalline + String Inverters
Lowest upfront cost while maintaining acceptable quality and performance.
- Panel brands: Risen, Seraphim, Jinko Tiger
- Inverter: SMA, Fronius, or Sungrow string inverters
- Installed cost: GBP 0.65-0.75/Wp
- Expected payback: 4-5 years
Large Scale (500kW+): TOPCon Bifacial + Central Inverters
Optimised for very large factory roofs with white membrane surfaces.
- Panel brands: Longi, Trina Vertex, JA Solar DeepBlue
- Inverter: SMA Sunny Central, Huawei SUN2000
- Installed cost: GBP 0.60-0.70/Wp
- Expected payback: 3.5-5 years
Next Steps
Choosing the right technology is just one part of a successful factory solar installation. Work with experienced commercial installers who can assess your specific situation and recommend the optimal configuration.
Questions to Ask Your Installer
- 1. What panel technology do you recommend for my roof type and location?
- 2. How do the proposed panels perform in UK low-light conditions?
- 3. What inverter configuration optimises my system given any shading?
- 4. What are the warranty terms and claims process for the panels and inverters?
- 5. Can you provide LCOE calculations comparing different technology options?
- 6. What monitoring system is included and what data will I have access to?
Get Expert Technology Recommendations
Our network of MCS-certified commercial installers can assess your factory and recommend the optimal solar panel technology for your specific requirements, budget, and goals.
Request Technology Assessment