With developments in module making having hit the fast track, it is increasingly becoming difficult to differentiate modules based on a particular module technology. The pressure to reduce cost and increase power ratings has been motivating module manufacturers to integrate multiple advanced module technologies into a single module product.
On the other hand, they have also started paying special attention to applications when designing the module product. In fact, the applications for PV are increasing beyond the mainstream of residential, C&I and utility. Innovations at the module level are increasingly being integrated into several other day to day aspects of life. This stream of PV is generally termed as integrated photovoltaics. According to Fraunhofer ISE, integrated photovoltaics blend into the outer surface of buildings, roadways, railways, vehicles, agriculture and water bodies in a way that these surfaces have an additional functionality of generating power on top of serving its core purpose.
Some of these applications are already known by their colloquial names — building integrated PV (BIPV), agricultural PV (Agri PV), Floating PV (FPV), and PV integrated into vehicles (VIPV). Using PV as a noise barrier on roads and railways is also a well-known application. These applications have specific requirements in terms of weight, format, size, shape and even color. While these are still niche, there is big interest from the leading PV manufacturers. However, while companies are working on different module designs specific to these new requirements, such products are yet to become fully commercially available.
The following section of the TaiyangNews Solar Module Innovations report, in addition to providing an overview, discusses the innovative module designs for respective applications. Here is a brief summary on FPV:
FPV is a small, but strongly emerging subsection of utility PV. Using water as an installation site instead of land is the primary attribute of this budding, but very promising, section of PV. An FPV system consists of the same components as ground-mount solar parks — PV arrays, mounting system, inverters, cables, fuses, switchgears, auxiliary load circuits, transformers, and security system. In addition, one component adds to the BOS — floaters — which holds the majority or the entire PV system on the water surface. FPV is relatively more expensive than a ground-mount installation, not just due to the addition of floaters, but also because of the special care needed to keep all components functioning effectively in humid and wet operating conditions.
On the other hand, FPV brings in several benefits. First, it solves the problem of real estate, especially in locations where land is scarce or at a premium. FPV can be easily integrated into commercial water bodies such as irrigation and drinking water reservoirs, aquaculture farms, and even hydropower generation sites, where FPV brings in synergistic benefits. It not only allows for effective utilization of the water surface, otherwise of no other use, the floating PV setup also suppresses the evaporation of water and improves overall water quality. On top, the power yield of FPV is estimated to be relatively higher due to the cooling effect facilitated by the water body. The benefits add on further when such a system is installed on a hydropower generation site, where the existing infrastructure can save on the additional costs required for such an exercise. However, the field of FPV is developing rapidly – total installed capacity has exceeded the GW level, and the first off-shore multiple GW projects are in the planning in Asia.
Similar to other components of FPV, the solar module used in floating applications must also exhibit high resistance to moisture ingression. Glass-glass is also the preferred configuration here, which is believed to offer better protection against moisture ingression. It also benefits from the water's reflectivity when using bifacial technology. Encapsulation materials with low water vapor transmission rate (WVTR) such as POE and junction boxes with high corrosion resistance are the other major changes required in BOM. While module makers are taking special care when making the panels for FPV, the stream is yet to earn a place for itself among the list of applications under which the modules are listed, which may change soon.
The Text is an excerpt from the recent TaiyangNews' Solar Module Innovations 2022 report, which can be downloaded for free here.