Bischof + Klein offers polypropylene-based backsheet for extreme solar cell protection

Facebook
Twitter
LinkedIn
Reddit
Email

Bischof + Klein has introduced a new generation of PV module backsheets, designed to provide greater stability when exposed to UV radiation and increased protection against moisture ingress. The new B+K ‘BackFlex’ PP backsheet is based on polypropylene and is therefore naturally resistant to hydrolysis. It can withstand more than 5,000 hours of damp heat testing (85°C / 85% r.h.).

Problem

PV modules are installed all over the world, and are therefore exposed to diverse, constantly changing environmental conditions for many years. The backsheet plays an important role in the lifespan of PV modules. It has to protect the inner parts against corrosion and hydrolysis by preventing the ingress of, for instance, water vapour over a period of 20 years and more. It additionally has to withstand the harsh climates to which PV modules are exposed. Electrical safety in terms of insulation also plays an important role. Finally, special requirements such as low shrinkage during vacuum lamination have to be met by the manufacturer.

Solution

The new B+K BackFlex PP backsheet developed by packaging and film specialist Bischof + Klein can withstand more than 5,000 hours of damp heat testing (85°C / 85% r.h.). Polyester (PET), in particular, is prone to hydrolysis due to its polymeric structure. The ingress of water vapour into PV modules can cause corrosion of the metallic components but also hydrolysis of the encapsulant EVA, leading to the formation of acetic acid. B+K BackFlex PP is said to reduce water ingress by more than 50% compared to market standards. System voltages can be high in PV installations so particular attention has to be paid to electrical safety in terms of insulation. B+K BackFlex PP is certified for a system voltage of 1.5 kV DC. The 360 µm B+K DuroFlex PP offers a dielectric strength of 60 kV. During PV module production, the module stack is vacuum laminated. In this process, backsheet shrinkage is minimised to reduce mechanical stress inside the module stack. The B+K BackFlex PP meets these requirements with unique shrinkage behaviour of no more than 0.3% in both dimensions, according to the company. 

Applications

PV module backsheet. 

Platform

The new B+K BackFlex PP backsheet can withstand more than 5,000 hours of damp heat testing (85°C / 85% r.h.) and is certified for a system voltage of 1.5 kV DC. The 360 µm B+K DuroFlex PP offers a dielectric strength of 60 kV. The optical reflectance of the backsheet significantly influences PV module efficiency. B+K BackFlex PP offers high optical reflectance within the solar spectrum that is comparable to market standards such as TPT or PPE. The backsheet is manufactured in a one-step co-extrusion process that leads to outstanding internal adhesion. No glue or solvents are therefore required to produce the product. 

Availability

May, 2018 onwards.

15 September 2022
Bifacial PV modules will be the dominant solar PV technology globally within one or two years; in the utility-scale sector, their market share is already above 70%. This webinar will provide a clear view on the successful implementation of bifacial technology, maximizing system performance and minimising LCoE.

Read Next

August 10, 2022
OMERS Private Equity has acquired a minority stake in the Arizona-headquartered solar operations & maintenance (O&M) provider NovaSource Power Services.
August 9, 2022
The Public Service Commission of the District of Columbia (DCPSC) has approved a 15-year power purchase agreement (PPA) with renewables developer Invenergy for 73MW of solar power to meet a 5% renewables target for district’s default electricity supply.
August 8, 2022
India deployed 8,359MW of solar PV in the first half of the year, marking a significant increase of 71% compared to the same period last year
August 8, 2022
Energy technology company AES Corporation is still on track to reach its target of 4.5-5.5GW in long-term renewables and energy storage contracts in 2022, having already signed 1,618MW in the year to date, according the firm’s Q2 financial report.
August 4, 2022
Hanwha Solutions is reportedly considering expanding its investment into US solar production if the newly agreed upon Inflation Reduction Act (IRA) is passed.
August 3, 2022
Tata Power subsidiary Tata Power Green Energy has commissioned a 225MW hybrid wind and solar project in the Indian solar hotbed state of Rajasthan.

Subscribe to Newsletter

Upcoming Events

Upcoming Webinars
September 7, 2022
15:30 AEST (UTC +10)
Solar Media Events
September 14, 2022
London
Solar Media Events
October 4, 2022
New York, USA
Solar Media Events
October 11, 2022
Virtual event