We’re seeing more demand for solar that doesn’t just sit on a roof — solar that becomes part of the building itself. That’s where Building Integrated Photovoltaics (BIPV) come in. These systems generate clean energy and replace traditional materials like cladding, curtain walling, or spandrel panels. It’s functional, future-focused design — especially useful in dense urban environments where roof space is limited.
At PV Plus, we’ve supported façade contractors on several London projects using Onyx Solar systems — wiring and commissioning the PV side as part of the build. Although we didn’t supply or install the glass itself, we’re familiar with the Onyx product range and have been recommended by them to UK clients seeking experienced support. Onyx Solar is based outside the UK but has earned a global reputation for premium, customisable BIPV installation — and we’re proud to be among the few UK-based installers with firsthand experience.
Types of Building integrated solar panels
- Curtain Wall Integration (Photovoltaic curtain wall) – replaces glazing within curtain wall structures
- Cladding Panel Systems – replaces opaque façade materials with solar glass
- Ventilated Façade Solutions – integrates with rainscreen or double-skin façades
Crystalline vs Amorphous PV Glass: What’s the Difference?
Crystalline Silicon Photovoltaic Glass
- Best choice for maximum energy output per m² (typically 100–180 Wp/m²)
- Made from standard-sized 158.75 x 158.75 mm opaque c-Si cells
- Transparency customisable from 0% to 75% VLT by adjusting spacing
- Higher yield and better ROI, but more opaque
Ideal where performance is priority and façade transparency isn’t essential.
Amorphous Silicon Photovoltaic Glass
- Uses a thin, uniform silicon layer between two glass panels
- Performs better in low-light and cloudy conditions
- Naturally semi-transparent, with up to 30% visible light transmittance
- Sleeker aesthetic with more colour and shape options
- Lower power output than crystalline (around 1/3), but better for daylighting and visual comfort
Best for vision areas and projects prioritising aesthetics and light.
Why Onyx Solar?
Onyx Solar is the most awarded photovoltaic glass manufacturer in the world, with over 100 international recognitions. Their solutions have been used in award-winning buildings like the Life Science Building at the University of Washington, Dubai Frame, and Bell Works in the USA. They’ve been recognised for:
- Innovation: U.S. National Glass Association’s Most Innovative Glass of the Year
- Sustainability: Multiple LEED-certified projects
- Performance: Best Photovoltaic Construction Material – NAN Award 2024
At PV Plus, we’ve worked on several UK projects using their glass. While we didn’t carry out the panel supply or façade build, we handled the electrical design, wiring, and commissioning side of things — and continue to support UK contractors looking to integrate Onyx BIPV into their builds.
Project Spotlight: Bell Works, USA
One of Onyx Solar’s most celebrated projects is Bell Works in New Jersey, USA — the former Bell Labs building transformed into a vibrant mixed-use development. Over 1,000 m² of crystalline silicon photovoltaic glass was installed across the façade, combining high power output with a clean, modern aesthetic. The system generates substantial on-site electricity while maintaining daylight and architectural appeal. As Ralph Zucker, CEO of Bell Works, put it: “The economics of replacing the existing glass with photovoltaic glass were shockingly affordable — likely more affordable than simply cleaning and replacing existing glass with simple glass.” It’s a benchmark project showing how BIPV can deliver serious energy performance without compromising design.
Customisation Options: Matching Design Intent
What makes Onyx stand out is how adaptable their PV glass is. Architects aren’t confined to one look — and neither are clients.
Size, Shape & Thickness
- Available up to 4000 mm x 2000 mm panels
- Laminated, double or triple glazing
- Compatible with Insulated Glass Units (IGUs)
Colour, Finishes & Cell Visibility
- From white, grey and blue to terracotta, marble brown, and corten steel
- Visible or obscured solar cells depending on design preference
- Textures available: acid-etched, ceramic frit patterns, tinted glass, anti-slip finishes
This is PV that doesn’t look like PV — it looks like premium architectural glass.
Design and Architectural Considerations
- Aesthetic Integration – With full customisation of glass, colour, and texture, design is never compromised
- Building Orientation – Façade exposure matters; south and southwest offer the best solar gain
- Planning Permission – Most façade-integrated systems will require planning approval — we recommend engaging local planning teams early in the design phase
Technical Installation Requirements
- Structural Mounting – Integrated into the building envelope, not surface-mounted
- Electrical Integration – Requires careful string design, inverter matching, and performance coordination
- Weatherproofing and Sealing – Glass must be correctly sealed within façade systems to maintain building airtightness and water resistance
Performance and Integration Benefits
- Dual-functionality: Generates clean energy and replaces cladding, glazing or balustrades
- Thermal & Acoustic Control:
- U-values as low as 0.7 W/m²K
- Solar factor (g-value) between 6%–41%
- UV and infrared filtering
- Monitoring & Control: Systems can be connected to remote monitoring platforms for visibility and fault detection
- Class A Fire Resistance — a major plus for high-rise applications
- Excellent ROI: Lower total build cost than cladding + conventional solar
“The economics of replacing the existing glass with photovoltaic glass were shockingly affordable — likely more affordable than simply cleaning and replacing existing glass with simple glass.”
— Ralph Zucker, CEO of Bell Works USA
Safety and Access Considerations
- Installation Safety Protocols – Often installed via scaffolding, mast climbers or crane lifts; full RAMS and site controls essential
- Maintenance Access Planning – Abseil anchors, BMUs, or planned access zones should be designed in early
- Fire Safety Compliance – All Onyx panels are Class A rated and meet UK guidance including RC62 and MCS requirements
Maintenance and Lifecycle
- Cleaning & Inspection – Ideally once per year; more frequent in polluted or coastal locations
- Component Replacement – Inverters and connectors have typical replacement cycles every 10–15 years
- Performance Monitoring – Essential to catch underperformance early and ensure long-term ROI
Frequently Asked Questions (FAQ)
Typically yes — especially in conservation areas or listed buildings. Early engagement is key.
Crystalline glass on façades can generate around 60–70% of optimally tilted roof panels. Amorphous generates less but offers better aesthetics.
Panels must meet Class A standards. Onyx Solar products are Class A rated and comply with UK MCS and RC62 guidance.
Yes — Onyx panels are fully customisable by colour, texture, and transparency. They can mimic traditional materials like corten steel or tinted glass.
Access must be planned at design stage — either via BMUs, scaffold points, or abseil anchors. Cleaning and checks should be done annually.
Final Word
BIPV isn’t just solar on buildings — it is the building. And when you’re working with Onyx Solar, you’re using one of the most advanced and adaptable systems on the market. At PV Plus, we’re familiar with their products, we’ve commissioned them on UK façades, and we’re here to help bridge the gap for UK contractors or clients considering BIPV.
Let us know if you’re planning a project that involves integrated solar — we’d be happy to advise, coordinate, and deliver the PV side to spec.
