Bifacial solar panels: Innovative, eye-catching, and best of all, more efficient

Editorial note: This article has been updated following the federal government's decision to end the special tariff exemption for bifacial solar panels.

Bifacial solar panels have grabbed everyone’s attention in the solar PV industry — for all the right reasons.

The tale of tariff exemption and bifacial solar technology

In June 2019, the US trade representative (USTR) issued a notice announcing that all bifacial solar panels will be exempt from President Trump’s section 201 import tariff duties.

However, after just 4 months, the USTR has decided to rescind the exemption on bifacial solar modules — completely dissolving it on October 28, 2019.

After evaluating its decision, the USTR, in conjunction with the Secretaries of Commerce and Energy, concluded that the exclusion of bifacial modules from the Section 201 tariffs undermined the attempts to safeguard domestic solar panel production.

In its ruling, the USTR pointed out that global production of bifacial solar panels is increasing. It argued that the continuation of the exclusion would likely result in increased imports of bifacial solar panels in the U.S., which would compete against the domestically produced monofacial and bifacial solar panels.

Thus, bifacial products are now subjected to a 25% tariff as of October 28, 2019. This rate will drop down to 20% in 2020. Regarding the decision, CEO and president of the Solar Energy Industries Association, Abigail Ross Hopper, stated:

“We’re obviously disappointed by USTR’s decision to revoke the bifacial panel exemption. USTR granted the exemption only four months ago, and only after a year-long process that included notice and comment and inter-agency review. In an extraordinary and unprecedented turn of events, the exemption was quickly rescinded without any opportunity for public notice and comment. This is unnecessarily squeezing the supply of panels in the United States, thereby inflating prices for consumers. In its rush to judgement, USTR missed an opportunity to address the significant shortage of domestic solar panels and its decision will slow the growth of an American economic engine. We look forward to making our case during the pending midterm review.”

Let’s back up: what exactly are bifacial solar cells, and how do they work?

Bifacial solar panels have solar cells that absorb light from both the front and the back. That means that besides capturing sunlight from the front of the panel, they also capture all the valuable sunlight that is reflected from the ground, as well as any diffused light that hits the back of the solar cells. Thus, they absorb more sunlight and provide higher efficiency than monofacial solar cells.

A solarium designed with 16 bifacial solar panels for a home in Wilmington, NC. Image source: Florian

This is an advancement over traditional 'monofacial' solar cells that make up the vast majority of existing PV solar systems. Monofacial panels, of course, can only generate electricity from just one side — the side that houses the solar cells and is directed towards the sun.  

Here’s a quick video that demonstrates the idea behind bifacial solar panels: 

What do the experts say about bifacial solar technology?

Solar industry experts are talking a lot about this highly energy-efficient bifacial solar technology. Here’s what they have to say: 

“With market penetration exceeding expectations in 2018, bifacial technology is set to account for one-third of global solar module production by 2022”
Edurne Zoco, Research Director at IHS Markit. Source

“Bifacial panels are a no-brainer. They will be the panel of choice for the utility-scale market. It is estimated that the solar farm in York will generate 20 percent more energy due to its combination of bifacial solar panels and trackers that enable each panel to follow the sun, compared with traditional static photovoltaic panels.”
Toddington Harper, Chief Executive of Gridserve. Source

“Bifacial technology captures more light, and it is not very much more expensive, so it makes sense.”
Cedric Philibert, International Energy Agency. Source

“Although bifacial technology may cost $0.05/W more to install than a monofacial PV system, a conservative 10% bifacial gain easily outweighs the risk”
Scott Stephens, Director of Technology Development at Clearway Energy. Source

Who are the top bifacial solar panel manufacturers?

‘Bifacial’ is definitely the new buzzword in the solar industry. Bifacial panels have become the topic of discussion at solar conferences and trade shows.

Some solar companies are ahead of the curve and have succeeded in achieving high power output from their bifacial product lines. 

These are the major players in bifacial solar panel manufacturing:

LG

Korean electronics conglomerate LG is currently dominating the market by offering an energy-efficient bifacial module with a front system of 390 W. Their NeON 2 BiFacial solar panels have an efficiency of up to 18.7%. These panels absorb sunlight from the front and rear sides via a transparent back sheet.

Canadian Solar

Canadian Solar has combined advanced bifacial cell technology with its double glass module manufacturing expertise to develop the ultramodern BiKu bifacial panels. These modules feature a well-engineered design, an automated manufacturing process, and stringent BOM quality testing. Canadian Solar claims that BiKu bifacial panels produce up to 30% additional power from the back side. These solar systems are highly durable, as they are made with anodized aluminum alloy frames.

Sunpreme

Sunpreme’s Maxima GxB 520 modules are made up of HCT cells in a frameless double glass structure. They are known for high power yield with a 20% backside power boost and over 600 W of bifacial output. The thin double-glass construction of Sunpreme’s solar panels provides appealing aesthetics that Sunpreme claims are well-suited for carports, roofs, and canopies. Sunpreme’s bifacial panels are free from light-induced degradation (LID) or potential induced degradation (PID).

JinkoSolar

JinkoSolar offers Bifacial 72M, a 72-cell module generating 380 W power. It increases systems’ output by 5-25%, depending on various reflective conditions. The unique frameless design of Jinko solar panels greatly reduces the possibility of the PID effect. Also, it is designed for high voltage (up to 1500 VDC) systems. The system also claims only 0.5% yearly power degradation, with 30 years of warranty.

Another one of their panels, the popular Swan module, has combined Cheetah bifacial cells and DuPont Tedlar PVF transparent film, allowing them to achieve an output of up to 400 W on the front side and a 20% energy gain from its rear side.

Other key market players for bifacial solar panels

Here’s a list of many other prominent market players who are involved in manufacturing advanced bifacial solar technology.

• Trina Solar
• AE Solar
• Suntech
• LONGi Solar
• Yingli Solar
• Sunpreme Inc.
• Prism Solar Technologies, Inc.
• SoliTek
• JA Solar

Major solar projects using bifacial solar technology

A number of large-scale solar projects built with bifacial solar modules have come online recently, and there are several more in the pipeline. These projects are an indication of how the bifacial solar industry is booming globally. Here are some noteworthy developments:

• In June 2019, Canadian Solar was awarded a Brazilian solar power project to install, which was around 130,000 BiHiKu modules (of 51.1 MWp capacity)
• In Feb 2019, Sunpreme and Tigo Energy completed a 750 kW bifacial system project for a commercial carport in the California Bay Area
• LONGi is working on a 224MW capacity power generation project in Mitchell County, Georgia. It is the largest "bifacial+tracker" power generation project in the United States

The positive attitudes of industry experts and ongoing project announcements show that the sun is shining brightly on bifacial solar panels.

Bifacial panels clearly have a promising future in the utility solar market. But what about when it comes to residential solar? Are they a good fit for homes?

Are bifacial panels a good choice for homes?

Short answer: no.

The biggest reason for this is bifacial solar panels don’t work well when installed on rooftops. Rooftop solar panels are mounted on frames which leave just a few inches between the panel and the roof surface. This means that very little reflected sunlight reaches the rear panel face, restricting bifacial solar production.

They require a large amount of space in order to avoid shading and to absorb the reflected light properly, making them less suitable for residential properties where real estate is limited.

Finally, bifacial solar panels currently come with a significant cost premium, and in residential setups they are unlikely to produce the additional power required to justify their higher price.

This means that traditional monocrystalline or polycrystalline solar panels are still the most cost-effective option for residential installations.

That being said, bifacial solar systems can still prove useful for certain residential applications. For instance, bifacial thin-film solar cells make sense when used for freestanding structures like pergolas, both providing partial shade and producing energy from both sides.

A solar patio designed from bifacial solar panels to capture sunlight from both sides. Image source: Prism Solar

Bifacial systems may also work for areas where there is no hindrance to the reflection of light. Canopies and awnings made from bifacial photovoltaics PV panels allow the reflected light to reach the back of the panels and generate additional sustainable energy for homes.

Conclusion: The bifacial solar panels market will take off but not all future panels will be double-sided

Bifacial solar panels are being hailed as solar energy's next big thing. With a higher rate of energy production, bifacial panels seem bound to take over the utility solar market in the US.

However, they are unlikely to have much of an impact on the stable residential solar market. A bifacial solar system mounted on the roof of a home can’t really capture the reflecting rays of the sun. Add to that their premium price and frameless design, and it’s clear that bifacial solar technology will not be a fit for most homes.

Before you go, check out these cool applications of bifacial PV technology

We leave you with some stunning and innovative applications of bifacial solar panels from module manufacturer Prism Solar.

Bifacial solar cells installed vertically as a verandah railing.

 

Bifacial solar panels incorporated into an awning.

 

Bifacial solar panels used in a drive-through.

 

Bifacial solar panels used to shade a railway station waiting area.

 

Bifacial solar panels used on a parking canopy.