In this blog, we take a deeper look at the technology behind bifacial solar modules, how they’re installed and mounted, where they can be used, and their advantages.
WHAT ARE BIFACIAL SOLAR MODULES?
Bifacial solar modules allow light to enter from both the front and rear sides of the panel generating up to 30% more solar power than monofacial or conventional PV panels, depending on where the system is installed and how it is mounted.
Developed in the 1960s, they were first deployed in the 1970s by the Soviet Space Program. In the 1980s, the development of PERC (Passive Emitter Rear Cell) – a technology created to achieve higher energy conversion efficiency – helped bifacial modules grow into prominence. Improved power and cost efficiencies have made bifacial PV modules more accessible and they’re now slated to be the industry standard.
BIFACIAL TECHNOLOGY
Bifacial PV panels are usually manufactured using p-PERC bifacial cells. Bifacial panels tend to be more efficient since each solar cell is made up of a single silicon crystal, allowing electricity-generating electrons more space to move. Polycrystalline bifacial panels tend to be a more cost-efficient choice.
The power rating on a bifacial module is generally 440 to 545 watts which indicates expected power generation under ideal sunlight and temperature conditions. While this power rating takes into account the power generation from the front of the panel, bifacial panels also present a second rating for the rear side of the panel.
Where traditional PV modules have an opaque backsheet, a bifacial module usually has a glass or clear backsheet. This enables the panel to capture reflected light. The cells on the back of the panel absorb light that is reflected off the ground which is called ‘albedo’ light. Albedo light capture is higher when the ground beneath the array has a white or reflective surface that reflects light more efficiently than darker colours. Research from Solar World indicates ground surface albedo values for concrete as 16%, greenfield or grass as 23%, white gravel delivers 27% higher power generation, while white-painted concrete can contribute anywhere between 60% to 80% depending on the type and thickness of the paint. White roofing membrane however delivers the highest albedo value of over 80%.
Usually placed on the back of the panel is a junction box that is smaller than the type placed on traditional arrays, which means it occupies less space and throws less shade on the back of the solar cells resulting in the creation of more solar power. In some cases, the junction box is separated into multiple units positioned along the panel’s edge to prevent shading, too.
HOW ARE BIFACIAL SOLAR PANELS INSTALLED & MOUNTED?
Since bifacial solar panels work differently from traditional modules, their installation and mounting are subject to several factors.
Type of module
Bifacial modules can be framed or frameless. Frameless panels are mounted with rubber clamps that hold the glass in place, they are PID-free and require no grounding. Framed modules are mounted like conventional modules.
Mounting requirements
Bifacial solar modules can be mounted horizontally and vertically – in most cases, vertical mounting is done in BIPV systems that are building-integrated.
Mounting and racking systems are specially formatted for bifacial installations to minimise shading and maximise exposure to sunlight. Bifacial modules require a special structure that mounts the panels at a higher height. The higher a bifacial module is mounted the more power it produces from its bifacial properties. These modules are usually mounted in fixed or tilted arrays. Tilted arrays are mounted to align and optimise light at sunrise and sunset.
APPLICATION OF BIFACIAL SOLAR PANELS
Extremely effective for:
– High-range commercial set-ups
– Utility-scale applications
– On-grid solar power systems
ADVANTAGES OF CHOOSING A LEADING BIFACIAL SOLAR MANUFACTURER
One of the leading manufacturers of solar systems, Emmvee’s Bifacial modules feature AR coated transmission glass, anodised aluminium frames, MC4 compatible connectors, PID resistance, and a mechanical load of 5400 Pa. Built to last, bifacial modules from Emmvee offer a host of advantages.
1. Better performance
Bifacial solar modules deliver higher power generation, especially where space is at a premium, adding more production of electricity at a marginally higher installation cost, so LOCE costs are reduced.
2. Higher lifetime power yield
Over their lifetime, bifacial panels offer a higher power yield as compared to conventional solar modules.
3. Improved durability & reliability
Made with double-sided cells, Emmvee’s solar modules are manufactured with the highest quality of raw materials under exacting manufacturing processes. Strong tempered glass and corrosion-resistant frames make these panels durable enough to withstand snow, hailstorms, strong winds, and harsh weather conditions. They offer excellent current distribution performance, with no degradation of electrical power for enhanced safety. What’s more, all modules come with a 10-year product warranty and a 25-year linear performance warranty.
4. Impressive aesthetics
These versatile modules offer excellent aesthetic value as they are transparent and can be used in a variety of ways, to add character and function when integrated with interior and architectural features. They can be used as pergolas, barriers or dividers, canopies, and brise-soleil.
5. Lower BOS cost
Emmvee’s Bifacial solar systems help reduce BOS costs because per panel wattage capacity is higher, requiring fewer panels. Balance of Systems cost or BOS includes all non-module costs like hardware including switches, inverters, support racks, etc, and soft costs like planning, labour, etc.
6. Low maintenance
In general solar systems require minimal maintenance and Emmvee’s bifacial solar panels will only need periodic cleaning and minimal upkeep.