Solar aesthetics combined with hail resistance class 5: the Activ'Glass BC Full Black in-roof solar module

The Solrif BC Full Black series – The new solution for high hail resistance in integrated solar roof systems

Hailstorms are becoming more frequent and intense. It is impossible to predict in which geographical regions they will cause significant damage. 

This makes it all the more important to be as well prepared as possible in all locations: especially when it comes to complex projects such as integrated solar systems.

The Solrif BC Full Black series

deSonna GmbH, a specialist wholesaler for building-integrated photovoltaics (BIPV) and a major German system provider for Solrif in-roof systems, now offers the Solrif BC Full Black series of solar modules, which, thanks to their extremely robust 4 mm ESG glass, have received certification for (Swiss) hail class HW5. 
And this is in accordance with the Swiss VKF procedure, which applies even stricter standards than its German TÜV counterpart.

But it is not just the outstanding glass hardness that sets the Solrif BC Full Black series apart; these innovative modules also clearly stand out from comparable products in other respects.
For instance, the Solrif BC Full Black series from Aktiv'Glass utilises the latest IBC cell technology with a rear-contact design and no visible conductor tracks. As a result, the module surface appears matt black across its entire surface from all distances, thereby enabling particularly harmonious architectural implementations.

About the product

The BC Full Black series as an integrated solution within the proven Solrif system from Ernst Schweizer AG

The realisation of the architectural aesthetic is significantly supported by a further decisive advantage of the Solrif Aktiv'Glass BC Full Black series: it utilises the proven and patented Solrif system from Ernst Schweizer AG. This means that, as an integrated photovoltaic solution (solar roof tiles) on roofs, it combines aesthetics, energy efficiency and durability. 

Thanks to the Solrif system, the modules can be installed quickly and easily and are suitable for both full and partial roofs. 

The system also offers options for skylights, dormers, chimneys and other roof penetrations. Furthermore, blank panels and custom shapes are available for various roof types. 

The specialist staff at deSonna BIPV GmbH are happy to answer any questions you may have regarding in-roof solar systems and, of course, specifically regarding the new Solrif BC Full Black series from Aktiv'Glass.
Telephone: +49 8841 9 99 99 – 33
Email: bipv@desonna.de

A brief digression: developments and future forecasts regarding hailstorms

According to research by the Institute for Meteorology and Climate Research – Tropospheric Research (IMKTRO) in Karlsruhe, a statistically significant increase in hail events has been observed in southern Germany – particularly along the border between Baden-Württemberg and Bavaria. Data from the last
20 years was analysed. 

Studies (including those by the reinsurer Munich Re) also show that, in a climate scenario assumed to be moderate, severe hail events (hailstone size ≥5 cm) could increase by 10–20% across Europe, and in some parts of Germany by as much as 30–40%. 

In our view, the risk across Germany will also increase due to the fact that increasingly dry soils in the northern half of Germany are leading to a sharp rise in airborne dust and thus also in the quantity of condensation nuclei – i.e. the initial particles involved in the formation of rain and hailstones. 
Together with the increased thermal activity caused by rising temperatures – which is largely responsible for the size of hailstones (thermal updrafts repeatedly lift the hailstones to great heights, where further layers of ice then accumulate) – increasingly severe hailstorms will result.

Background to the hail resistance classes (HWK)

Hail resistance classes (HWK or HW) are predominantly used to provide a standardised description of the resistance of roofing (including solar modules as well as, for example, roof tiles) and of building envelope components (plaster systems, panels, etc.).
These (Swiss) classes indicate how well a component can withstand hailstones of a certain size without sustaining damage. The Swiss classification generally ranges from HW 1 (low) to HW 5 (very high), with the numbers referring, amongst other things, to the diameter of the assumed hailstone size and the impact force. 

The (Swiss) classes are determined experimentally via so-called hail simulation tests, i.e. the component to be tested is subjected to multiple impacts from clear ice balls of varying sizes at defined points within a realistic test setup.
The test conditions are designed to replicate the laws of physics: larger hailstones fall from the sky faster and strike with greater velocity than smaller ones. The impact energy increases disproportionately with increasing hailstone size.

Differences between the test procedures of VKF (Switzerland) and TÜV (Germany)

The Swiss VKF (Association of Cantonal Fire Insurers) procedure uses standardised test methods (IEC, ISO) in accredited testing institutes, in which ice balls of defined sizes and velocities are fired at the modules (or components). 

Classification ranges from HW 1 to HW 5 based on criteria such as watertightness, light transmission, mechanical properties and the appearance of the impact points. 

The test results are mandatory for hail insurance classification in Switzerland. The
certificates are stored in the Hail Register (www.hagelregister.ch). 

Germany does not have a national register or mandatory system equivalent to the VKF. However, similar test methods are carried out by testing organisations (e.g. TÜV Rheinland) in accordance with IEC standards (IEC 61215). 

However, the IEC standard only specifies minimum requirements (≈25 mm hail); there is no graded classification system such as HWK 1–5 associated with it. 

The test result is therefore limited to Pass/Fail. 

The components (modules) are issued with an IEC certificate (e.g. IEC 61215). In Germany, there is no public register of HW classes.

Insurance-related significance of the hail resistance classes (HWK)

There is no legal obligation to install a specific HWK. However, it appears that insurance companies (residential buildings, PV systems) in southern Germany, particularly in high-risk hail areas (e.g. the Swabian Alb, Allgäu, the Alpine foothills, Upper Bavaria), often recommend or even require minimum classes. 

In this context, insurers often differentiate premiums by region and risk class, or reduce the excess or offer lower premiums if a hail resistance class of ≥ 4 can be demonstrated. For increased cover or extended policies, proof of HW 4–5 may be required. 

In high-risk areas, HW 5 may be a prerequisite for the insurance company to reimburse claims in full at all.