How MPPT is Shining Light on Bifacial Solar Panels | SolarEdge UK
Close mobile menu

How MPPT Technology is Shining New Light on Bifacial Solar Panels

All Articles

Anna Ben-David

Content Writer

October 27, 2022 Comments ()
facebook icontwitter iconlinkedin icon
All Articles

How MPPT Technology is Shining New Light on Bifacial Solar Panels

1.3MW Castle Plaza Australia

The global demand for bifacial solar panels, panels that produce solar energy from both sides, is growing massively, with market share predicted to reach 35% of all global solar energy installations by 2030. This is largely because bifacial solar panels not only produce more energy, but they have also become significantly more cost effective.

If the goal of a PV system is to have the lowest Levelized Cost of Energy (LCOE, the cost of solar power production divided by the lifetime energy production of the solar project), then consider that an optimally placed PV system with bifacial panels can result in 10-15% lower LCOE, resulting in higher return on investment.

What is a bifacial solar panel and how does it work?

Bifacial solar panels are panels that convert PV energy from the front and back sides of the module, as opposed to the traditional ‘monofacial’ panels that produce on one side only. With monofacial solar panels, the front is comprised of photovoltaic cells (made up of semiconductors), while the back side is protected by a backing sheet. Bifacial panels utilize photovoltaic cells on both the front and rear . This enables power production also on the back side, increasing the amount of energy that can be produced by around 6-10% or more in some cases1


monofacial panels
bifacial panels

Which types of PV Systems work best with bifacial modules?

It's important to bear in mind that bifacial modules may not be suitable for all installations, but best suited for tilted systems and  areas with high surface albedo. Some examples of this would be areas with white concrete, snow and ice, desert sand, or water. Bifacial modules may produce more energy when installed in optimized conditions.

Why SolarEdge inverters are best for bifacial modules

While using bifacial solar panels can yield more energy, it also brings more complexities. Installing SolarEdge’s smart PV solutions in a bifacial system solves many of these complexities and improves the system LCOE.

As with monofacial panels, bifacial panels can experience module mismatch causing potential power losses and dragging down the overall system’s performance. This is common in all types of solar panels; however bifacial panels are even more susceptible to module mismatch because the light that hits the rear side is less uniform than the front. There are several reasons for this:

  • Inconsistent surface underneath the modules (from uneven snow or glass, different soil or material conditions, and more)
  • Different angles of the sun or shading by other modules and racking
  • Irradiance differences between modules located at the edge of the rows and in the middle, often called “edge effects”
  • Higher module degradation, ripples in floating PV, foliage growth in ground mount systems, and more

Installing a SolarEdge system with bifacial modules is optimal for maximum energy yield and faster return on investment (ROI). The SolarEdge solution utilizes Maximum Power Point Tracking technology (MPPT) that comprises a smart inverter with Power Optimizers connected to panels in 2:1 configuration in commercial installations. In traditional PV systems, even if one module produces less energy due to mismatch, production of the entire string is lowered accordingly. With the SolarEdge’s DC optimized topology, these power losses caused by mismatch between modules are mitigated, resulting in maximum power generation from each individual module.

Residential Panel Comparison

Because each panel performs individually, this enables more flexibility in the design of the system, including installing more panels at different angles or with inconsistent shading, as often occurs with bifacial panels. Using SolarEdge inverters and Power Optimizers eliminates these power losses.

Additionally, bifacial modules must be mounted on a higher racking system in order to expose the back to reflective sunlight. But with SolarEdge’s design flexibility, modules connected to SolarEdge Power Optimizers can be mounted at any angle, tilt, or orientation while still producing more energy. The extra energy produced over the system’s lifetime equates to better LCOE and a measurable increase in ROI.

In several sites with bifacial panels, the SolarEdge Monitoring Platform has shown that SolarEdge’s commercial PV solutions provided 4-7% more energy than initially expected from the PVsyst models, as shown in the chart below:

Bifacial Chart

Powering the largest PV system in rural Alaska

Kotzebue, Alaska has snow over 60% of the year, so when it came time to select the panels for their 576kW ground mount PV system, bifacial modules coupled with SolarEdge’s three-phase inverters with Synergy Technology and Power Optimizers were a great fit. SolarEdge’s smart PV solution was ideal for this project for several reasons. SolarEdge’s DC optimized commercial solution eliminated mismatch losses by almost 3% in the first year compared to a traditional string inverter. In addition, the energy gain is estimated to be over 6% by year 20, due to module degradation according to PVsyst modeling. By pairing SolarEdge’s inverter and Power Optimizer combination with bifacial modules, an additional gain of at least 5% is expected. Another added benefit is that the Kotzebue Electric Association can remotely troubleshoot through the SolarEdge Monitoring Platform, further reducing onsite visits and maintenance and lowering their O&M costs.

“With SolarEdge MPPT technology combined with bifacial panels, we expect to generate more energy than initially estimated.”
Matt Bergan, Engineer, Kotzebue Electric Association, Alaska

Bifacial Solar Panels

The Path to Making Bifacial Shine

Solar power could provide a quarter of global electricity needs by 2050, but for that to happen global capacity must reach 18 times current levels. That is why bifacial modules are so critical, with some manufacturers and industry analysts predicting they will eventually overtake mono-facials as the go-to technology, especially in ground mount solar installations. The key to worldwide adoption ultimately depends on the ability to overcome module-mismatch that is common in bifacial modules to extract the maximum energy production airing bifacial solar panels with SolarEdge’s DC optimized commercial PV solution can yield more energy, and lead to an overall higher return on investment and lower Levelized Cost of Energy

Add new comment

This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.


Similar Articles

Renewable energy trends
Renewable Energy Trends to Watch in Solar – Part 1
Nitsana Bellehsen | February 09, 2023
We’ve come a long way since ancient Greek homes were kept toasty using passive solar heating and since the Romans warmed their bathhouse water from the sun. New customer needs, innovative new products, and exciting new inventions are being put to use to harvest energy from the world’s most powerful energy source. So, as this year gets underway, let’s look at some of the exciting renewable energy trends that we can look forward to seeing more of in 2023. 1. The Rise of the Prosumer – and Energy Management “Prosumers”, as envisaged by Alvin Toffler in his 1980 book The Third Wave, are consumers who take an active part in the process of production. Indeed, homeowners and business owners with a PV installation, are active prosumers – who produce some or all of their own electricity and even sell it back to the grid. With the growing popularity of PV as a renewable energy source, coupled with the increased cost of electricity, this growing group of prosumers require additional tools in order to maximize the options available to them. As PV adoption grows, optimizing its use becomes even more critical. The prosumer has many decisions to make on a daily, hourly or even minute-by-minute basis: should I store my PV for later or use it now? When is it most efficient to run the washer/dryer– or for a factory owner, how can I take best advantage of my on-site solar production to power my manufacturing line? Should I charge my electric car with solar power? When? Enter stage left, energy management. PV is designed to provide its owner with financial benefits, as well as sustainable alternatives. But system owners have more pressing things to do with their time than program and monitor their home energy around the clock. These operational decisions should be able to be made automatically with minimum attention required from the PV system owner in order to optimally take advantage of their PV production. Fortunately, SolarEdge has built smart energy management into SolarEdge Home, the SolarEdge residential solution. As an integral part of our smart energy ecosystem, smart energy management is easy to deploy. Homeowners utilize load controllers to manage essential loads (specific appliances that need to remain powered on), select their preferences, while the SolarEdge Home Operating System orchestrates the home’s energy automatically. Homeowners monitor performance through the mySolarEdge app and can make changes if required. SolarEdge makes becoming a prosumer particularly lucrative for users. 2. Community and Multi-dwelling PV Installations Community solar is an exciting renewable energy trend that is growing in popularity and in applications. According to the U.S. Department of Energy, community solar is defined as “any solar project or purchasing program, within a geographic area, in which the benefits of a solar project flow to multiple customers such as individuals, businesses, nonprofits, and other groups.” These types of projects provide solar energy access to individuals or businesses that could not otherwise harvest their own solar energy. The beauty of these installations is that they accelerate solar energy adoption and decarbonization in a region, while democratizing the process, making solar energy accessible to everyone. Here are some interesting community solar stories: Puerto Rico – An ambitious community solar project that is also exciting because of the significant quality of life improvement it offers. Puerto Ricans have been subjected to deadly hurricanes which have repeatedly knocked out their access to electricity, especially when they needed it most. Even in the best of weather conditions, their power grid is frequently thwarted by repeated outages which leave residents without electricity. In response, many Puerto Ricans have been installing solar solutions. And now, 7,000 of those installations will be connected to form the US territory’s first virtual solar virtual power plant (VPP). This will provide power and stability to Puerto Ricans who aren’t able to install their own PV. Working together with utility companies, the aim is to reduce reliance on the fossil fuel operated “peaker” plants that are accessed when there is high demand – and enable more residents on the island to benefit from solar. Africa – Many areas in Africa did not have access to energy at all prior to the availability of solar. A number of initiatives led by partner organizations that include the World Bank, SNV Not for Profit and others have created mini-grids in areas not previously connected to solar, with pay-as-you-go and other plans to ensure accessibility for impoverished residents. To date, more than 32 million Africans have access to basic electricity because of projects of this type. This is only a drop in the ocean of the more than 600 million who still are waiting for that access, so there is more work to do. Around the globe Community solar doesn’t only assist in areas of need. The US alone boasts 1600 different community solar projects.  41 US states plus D.C., have at least one community solar project installed, all together, producing 5.3 gigawatts as of Q3 2022. Europe is home to an estimated 10,000 community solar projects. In Germany alone, 900 energy co-ops sell solar to homes and businesses.  And this is only the beginning of a trend that is rising, with solutions for individual multi-resident dwellings becoming mainstream. SolarEdge community solar A recent SolarEdge community solar site in the US is the Hartford Pike Project, led by Sunlight General Capital. The project is situated on a 12-acre site in Foster, Rhode Island, on undulating ground that also experiences shading from nearby trees. This is a typical scenario in many of the locations available for community solar, and fortunately, it is not a hindrance with SolarEdge technology. SolarEdge Power Optimizers attach directly to solar modules and enable each module in the string to perform independently at its maximum power point. Underperformance due to shading, for example, will not impact the other modules on the same string, ensuring maximized energy production of the entire system. This technology also afforded Sunlight General Capital precise module level monitoring. As James Pochez, Head of Product Development explains, “To optimize energy production…we needed to be able to monitor all 15,800 solar modules in real-time and ensure we can pinpoint any issues quickly and efficiently. As the owner/operator of this project, the decision on what to build will impact our business for the next 25-years plus. It is in our best interests to choose the best quality solution available.” In its first nine months of operation, the Rhode Island project generated 5.81 GWh of solar energy, of which 3.35 GWh was made available to local residents and businesses through the community solar initiative. 3. Hybrid Hydro and Solar Water and sun. Could it be a marriage made in heaven? Both hydro and solar are renewable energy technologies that help countries around the world reduce their dependence on fossil fuels. Yet the use of each alone includes certain drawbacks. A study undertaken by the European Joint Research Center estimates that covering just 1% of Africa’s hydroelectric reservoirs with solar panels could double their capacity to 58 gigawatts and increase overall generating capacity by up to a quarter. Hydroelectric plants currently generate 90% of the electricity used in several African nations and are significant to the power grid in the US and elsewhere. However, severe drought experienced in many of these same regions, coupled with natural evaporation, is threatening the viability of many of these plants. Due to drought, a hydropower dam in California was shut for several months, and other huge dams reduced production. In one year alone, 2016 to be exact, 42 billion m³ of the hydropower industry’s water evaporated. In tropical locations, up to two meters of water can evaporate from the surface of hydroelectric plants each year – sometimes up to half of the water they capture. Placing solar panels over hydroelectric plants is a viable solution to reduce evaporation, as proven by researchers at the University of California Merced, studying the effects of covering a 4,000-mile water canal with solar panels. They learned that such an installation could save 65 billion gallons of water annually.  This renewable energy trend could have huge potential. Adding floating solar panels at these sites is simple, as hydropower plants are already connected to the grid.  The synergy of the two technologies makes for a much more stable environment. Solar can compensate for hydropower during dry periods and the two can balance each other out, depending upon the time of day and surges in electricity use. Floating PV provides a higher energy yield because the water is cooler than the earth. Installing panels can also assist with reducing algae growth where it is not welcome. More renewable energy trends to come… In a future blog we’ll talk about some other renewable energy trends – like new EV applications, job opportunities around the globe, where solar panels go when they die, and other ways PV is working together with other industries for amazing, complementary results… Stay tuned!
Read more
Solar Panels
Getting Your Creative On with Solar Panels
Oren Zaltzhendler | April 14, 2022
As the impact of climate change continues to disrupt our lives, many governments are looking toward the sun as a source of renewable energy. Some, like the United States and Switzerland, are even offering incentives to go solar. And it’s working. According to the International Energy Agency (IEA) Photovoltaic Power Systems Program (PVPS), the rate of PV installations across the world during 2020 was more than double compared to 2016, and more than 7 times compared to 2012. While most companies and homes that go solar do so with the intention of generating as much energy as possible, others consider the aesthetics to be no less important. Design, shape, visibility, and utilization of solar panels (otherwise called photovoltaics or PV panels or solar modules) for additional income such as advertising are some of the considerations. Mickey Mouse, panda bears, and wild horses Take, for example, Disney, which is using PV panels in the shape of Mickey Mouse as part of their brand. In fact, the Disney company is harnessing the power of the sun at four installations across the globe and, according to their estimations, these sites will produce enough energy to power over 65,000 homes for one year. And there is a company in China which invests in and operates PV fields in the shapes of smiling panda bears. In fact, a solar project in China earned a new world record for the largest ever solar panel image – it occupies an area of about 1,400 square meters, the same size as roughly 200 football fields! According to the Dailymail, the project produces power for over a million houses and was built as a part of the government’s effort to promote tourism and energy resources in the Gobi Desert. The image shows the local horse breed that characterizes the region. This all sounds great in principle, but is there a downside? A solar site that is designed in a special shape could potentially enhance a phenomenon known as module mismatch where some modules can produce less power than others. Module mismatch can limit the power production of the stronger modules in the string to that of the weakest modules. However, companies such as Kia, Hyundai, and Audi have designed sites incorporating their logos without compromising on the generated energy. These companies are using SolarEdge Power Optimizers to enable each solar module to generate electricity at its maximum potential.   What are solar modules? With many “creative” solar energy solutions still in the early development stages and facing their own engineering challenges, let’s first understand a few basics about PV panels which can be found in our neighborhoods, commercial parks, farms, and even in remote unpopulated deserts, and look at several interesting solutions. First of all, what’s the difference between solar modules, solar panels and PV panels? In most cases, not much. They are all terms that can be used interchangeably depending on region.  They are made of silicon, glass and metal and, when exposed to the sun, they produce power. But for all practical purposes, however you refer to them – modules or panels -- each is single unit of a packaged, connected assembly of solar cells, wires, electronics, glass, and a frame. A standard PV panel comprises an array of solar cells with various spacing configurations. The cells are interconnected with metallic conductors and positioned between the front glass and a back sheet. The most common solar cells are made of crystalline silicon that is dark blue in color and is cut into the familiar rectangular shape. The conversion efficiency of these PV cells depends on the spectrum of the irradiance – some frequencies of light are converted better than others. Some PV technologies can also produce power from irradiation that passes through the cells and is reflected by the back sheet into the back side of the cell. It’s worth mentioning that in addition to the standard PV panels, there is another type of solar panel -- bifacial PV panels which are designed to convert radiation from the front and back side of the panel. Bifacial PV panels utilize glass instead of a reflecting back sheet. In this case, the silicon is placed between two glass sheets, allowing radiation to be reflected back from the ground directly on the PV silicon. Let’s get even more creative with solar There are lots of ways to change the overall look of solar panels, some of which are even manufactured in monochromatic red, green, gold, and silver. One of the most popular is to paint the gap between the cells in a dark color, making them look more homogenous. But this does not come without its challenges. Homogeneous colored panels are great for places where the panels are located far from sight. However, sometimes the metallic conductors can be seen through the paint. Some companies eliminate all metallic conductors from the front side of the panel with technologies that enable back contact PV cells, leaving the front of the cells polished and flat. There are also “skins” that can be used with any panels in a process that closely resembles tinting a car’s windshield. Companies even make use of these skins for advertising purposes or blend them in a patterned environment. The main challenge in a painted front surface of a solar panel is that it blocks a portion of the light, negatively impacting the panel’s efficiency and essentially producing less power. Some technologies mitigate the negative effect of paint by using specific colors and materials that allow most of the light to reach the silicone behind them. Another approach is to reduce the amount of paint by painting only small dots while leaving the gaps between the dots completely unpainted instead of painting the entire surface. Getting solar in shape The traditional rectangular-shaped solar modules were designed to address engineering and economic considerations. An important consideration for a solar panel is that most of it be covered with silicon as the gaps between silicon cells and the frame around them are not utilized for producing power. Therefore, solar panel manufacturers increase the portion of the silicon area of their panels by reducing the gaps between cells and the width of the frame. This criterion is sometimes referred to as the “packing factor.” Rectangular cells can be packed better than circular cells - combined with a rectangular frame we get a good packing factor. So, what happens when the installation site is not rectangular? The remaining area is usually left unutilized`. Some manufacturers have begun introducing PV panels in various shapes such as triangles and trapezoids. With more area utilized, more power is subsequently generated. This solution is beneficial for sites with tiled roofs and a non-rectangular shape. There is also a growing niche of curved solar panels which are suitable for curved roofs. The curved surface of the solar panel poses its own problems as different parts of it face different directions. For example, curved solar panels that encircle streetlights face the sun on one side while the other side is shaded, resulting in a mismatch. Some solar panel manufacturers are dividing the curved solar panels into small sections, then electrically grouping sections that face similar directions together. This solution allows curved solar panels to produce power even under significant mismatch conditions. Looking towards the future Solar panel aesthetics are a major consideration that is gaining traction as a growing number of technologies are becoming commercialized. In fact, building-integrated photovoltaics (BIPV) is expected to develop rapidly due to government regulations and polices. This means that more panels will be integrated into new buildings, making the design and aesthetics key characteristics of a solar installation. This rapidly growing market could foster more innovative design concepts that may even become standard. I expect to find more aesthetic PV products in branding, advertisements, rooftops, and large utility fields. If you find any, please let us know in the Comments.
Read more