Bifacial modules are taking over the market - at least that is the impression you get if you believe the producers of cells with both an active front and an active back for power generation. At Intersolar Europe 2019, this year's trade fair for photovoltaics in Munich, exhibits of this kind could be found at the booth of nearly every major module manufacturer. Companies have outdone themselves with the amount of output the front side alone can deliver - figures which when combined with the output of the back of the modules, add up to as much as 30% under optimum conditions. Added to the 425 W generated by the front of the panels, for instance, are as much as 140 W of output from the back, so that modules from manufacturers like LONGI Solar and Trina Solar promise to deliver significantly more than 500 W, making them ideal for efficient power generation in a limited space - at least that's the theory.
The reality does not look quite so promising, however. Demand for this module technology, and thus the actual extent of its use, is still very limited, at least in Central Europe. Nevertheless, dealers and manufacturers are currently offering more and more products available on short notice that can be purchased at least in small to medium quantities.
An increasing supply at the beginning of the year prompted me to include bifacial modules in my analysis and later in the price index. It should be noted that the type and design of the products analyzed can vary greatly. In addition to glass-glass modules - with or without frames - some manufacturers also offer glass-film modules, which means that the manufacturing costs and thus the selling price vary considerably. Wholesale prices range from 0.32€/W for bifacial modules from JA Solar to more than 0.60€/W for products from LG Electronics. As with all price points in the index, the price shown is an average of all brands and supply chain levels.
Overall, prices have remained largely stable across all technologies over the past month. Only mainstream modules continued on a downward trend. At the end of the quarter, some suppliers' inventories were well stocked due to the unexpectedly sluggish demand in early autumn, both in Asia and in Europe. As a result, larger inventories were dumped on the market on short notice at special prices, which then put pressure on the competition. Most of these module inventories were quickly reduced, however, due to selling prices slashed by as much as 15%, meaning that higher material costs can be expected again in October, as some module manufacturers have already announced. The stock clearance operation essentially concerned only modules in the lower output classes of each category.
But back to bifacials: demand for these modules is still quite low, mainly due to the lack of experience with the technology, and thus the absence of concrete applications. Experts still cannot agree on standardized data and test procedures, which puts planners at the mercy of manufacturers' forecasts of the potential increase in performance under certain conditions. According to certified test procedures, only the front side performance can be measured and indicated, even though many test institutes have been developing new procedures for some time. Also, only a few simulation programs, PVSol and PVsyst for example, have been able to deal with this technology and added the corresponding products to their databases. In addition, the simulation result is greatly influenced by correctly determined environmental data. Some of the larger EPCs therefore first set up small test systems to determine the necessary parameters in comparison with conventional installations and then calculate a more reliable estimate.
Thus, there is no real comparability even between the products of different designs within this category, and the actual profitability of bifacial projects is still uncertain. Although the price differences are only some 10 to 30 percent higher than comparable monofacial standard modules (high efficiency), the yield gain on the basis of empirically determined data from existing test systems is often no more than just 10 percent, at least for simple rack-mounted rooftop systems with no other special features that would inevitably lead to higher costs. Additional yield could only be achieved by optimizing the support structure so that the module backs are completely free of shading, and by increasing the reflectivity of the surface beneath the panels.
However, demand for bifacial products is already much higher in some parts of the Middle East, as well as in Asia - that is, everywhere where large ground-mounted plants are built in desert-like regions. Tracked systems in particular allow the modules to capitalize on all their advantages. The United States is also an attractive market, as bifacial solar modules are exempt from existing punitive tariffs. Only here in Central Europe will it probably take some time for the double-sided modules to gain a foothold. Although small to medium-sized roof systems are increasingly equipped with highly efficient panels, bifacials have yet to find their way into this market.
Overview of the price points by technology in September 2019 including the changes over the previous month (as of September 23, 2019):
