Bifacial photovoltaics are currently a popular trend in solar energy. While double-sided panels are still more expensive than traditional single-sided panels, they significantly increase energy production where appropriate. This means faster payback and lower cost of energy (LCOE) for solar projects. In fact, a recent study showed that bifacial 1T installations (i.e., bifacial solar arrays mounted on a single-axis tracker) can increase energy production by 35% and reach the lowest levelized cost of electricity (LCOE) in the world for most people (93.1% of land area). These numbers are likely to improve as production costs continue to trend downward and new efficiencies in the technology are discovered.
      Bifacial solar modules offer many advantages over conventional solar panels because electricity can be generated from both sides of the bifacial module, therefore increasing the total power generated by the system (up to 50% in some cases). Some experts predict that the bifacial market will grow tenfold in the next four years. Today’s article will explore how bifacial PV works, the benefits of the technology, some of the limitations, and when you should (and should not) consider them for your solar system.
Simply put, bifacial solar PV is a solar module that absorbs light from both sides of the panel. While a traditional “single-sided” panel has a solid, opaque cover on one side, a bifacial module exposes both the front and back of the solar cell.
      Under the right circumstances, bifacial solar panels have the ability to generate far more power than conventional solar panels. This is because in addition to direct sunlight on the module surface, they benefit from reflected light, diffuse light and albedo irradiance.
      Now that we’ve explored some of the benefits of bifacial solar panels, it’s important to understand why they don’t make sense for all projects. Because of their increased cost over traditional single-sided solar panels, you need to make sure that your system can take advantage of the benefits of a bifacial panel setup. For example, one of the cheapest and easiest ways to build a solar system today is to take advantage of an existing south-facing roof and install as many recessed panels as possible. A system like this minimizes racking and installation costs and helps you start generating electricity without too much red tape or permitting. In this case, double-sided modules may not be worth it. Because the modules are mounted closely to the roof, there is not enough room for light to pass through the back of the panels. Even with a brightly colored roof, if you mount a series of solar panels close together, there is still no room for reflection. Before starting your project, you absolutely need to determine what type of setup and system design is right for your unique property, location, and your or your business’ individual needs. In many cases, this may include double-sided solar panels, but there are definitely situations where the additional cost doesn’t make sense.
      Obviously, as with every solar project, the design of the system will depend on many different factors. Single-sided solar panels still have a place and won’t be going anywhere for a long time. That said, many believe we are in a new era of PV where high-efficiency modules reign supreme and bifacial technology is a key example of how high energy yields can be achieved using higher quality materials. “Bifacial modules are the future of the industry,” said Hongbin Fang, technical director of Longi Leye. “It inherits all the advantages of monocrystalline PERC modules: high power density for significant BOS savings, high energy yield, better low light performance and lower temperature coefficient. In addition, bifacial PERC modules also harvest energy from the back side, showing higher energy yield. We believe that bifacial PERC modules are the best way to achieve lower LCOE.” In addition, there are many solar PV technologies that have even higher yields than bifacial panels, but their costs are still so high that they don’t make sense for many projects. The most obvious example is a solar installation with a dual-axis tracker. Dual-axis trackers allow the installed solar panels to move up and down, left and right (as the name implies) to track the sun’s path throughout the day. However, despite the highest power production achieved in a tracker, the cost is still too high to justify the increased production. While there are many innovations to be made in the solar field, bifacial solar panels appear to be the next step, as they have the potential for higher energy efficiency relative to the marginal affordability of conventional panels.