Schaffhausen, August 2009
Plastic Piping Systems for the Photovoltaics Industry
Environmentally friendly solar energy was a hot topic long before the current discussions debating the growth market of “Desert Energy”from solar power stations for European industry and private homes. This trend is supported by current market data, which states that turnover as well as export quotas of photovoltaic component, machine and plant manufacturers have once again clearly increased within a range of high double figures in comparison with the previous year. However, this sector in particular places great emphasis on quality without compromise during the production of large surface solar cells. This means not least that all necessary media must be transported cleanly and safely. The GF Piping Systems “Total Plastic Solution” offers ideal conditions here.
In addition to substantial and consistent growth, a “green image” is of vital importance for the further development of the photovoltaics market. Power generated by solar cells is generally recognised as the most important component in the fight against global climate change. It is therefore not surprising that prestigious subsidies have ensured substantial growth rates for a number of years, not just in Europe. Energy production with the aid of photovoltaics has doubled every two years since 2002; global power production by means of photovoltaics was in the region of 12,400 megawatt at the end of 2007.
The development of high-performance photovoltaic cells continues
Mass-produced, silicone-based multicrystalline solar cell plates (c-SI) currently achieve an efficiency of around 14 percent. However, more efficient products are already available on the market. These consist for example of high-performance cells made from monocrystalline silicone, or so-called HIT cells. Both products already achieve an efficiency of approx.22 percent.
Apart from the traditional cell production process (c-Si), the production of thin-film cells, which provide efficiencies of approx. eight percent (a-µc-Si, CIS, CdTe), is currently also progressing at dynamic speeds. Their future market potential lies at > 20 percent, with worldwide projected capacities for 2010 of around 20 gigawatts.
Due to the current economic crisis, as well as increased pricing pressure applied to solar cells, many manufacturers have initially concentrated on the complete utilisation of existing capacities in 2009. Combined with the extremely restrained attitude of most banks with regard to credit finance for new production facilities, this situation has, this year for the first time,resulted in a stagnation of growth rates within a sector that has to date been used to nothing but success. Despite the current overproduction, analysts agree that the overall market over the next few years will be characterised by growing demands of around 30 percent on average. They support this assumption with the fact that the turning point for solar energy costs (the grid parity) will probably be reached as early as between 2011 and 2015. During this time period, average energy costs for solar technology will have fallen to the level of conventional energy costs and will subsequently fall below these conventional electricity costs.
Interesting supplier market for piping manufacturers
Georg Fischer Piping Systems recognised the importance of this market very early on. The result was our range of successful solutions for the transport of media as well as for traditional solar cell production and the production of the new thin-film cells. The decisive factor behind our success is our “Total Plastic Solution”, offering individual piping concepts consisting entirely of plastic, as well as planning with the aid of a standardised design, in combination with the services of our specialist staff, who implement precise installations on site all over the world.
Plastic solutions:economical and safe
The silicon discs used for traditional photovoltaic production processes - wafers with a dimension of 150 x 150 mm cut from a polycrystalline silicon block - require a special and very complex wet surface process involving cauterising and cleaning. This process uses various acids as well as oxidising chemicals, caustic solutions and anorganic salts. Added to this are mixtures of these chemicals, as well as water in different qualities, such as distilled, deionised, demineralised or ultrapure. Added to these are mixtures comprising these chemicals, as well as water of various qualities, such as distilled, deionised, demineralised or highly purified. The acids used for example include fluoric acid, sulphuric acid, nitric acid, phosphoric acid or even acetic acid. Oxidising chemicals used are for example hydrogen peroxide or potassium permanganate, whilst the caustic solutions used include calcium hydroxide or sodium hydroxide. Anorganic salts may for example include fluoride, sulphate or chloride.
Because of the highly corrosive nature of many of these media and compounds, it is impossible to use metal pipes for these applications,as only very few precious metals, such as high-alloyed steel or special non-ferrous alloys, would be suitable. Pipes made from platinum or gold are of course out of the question for obvious reasons, whilst alloys are usually very expensive and often have a limited working life. Salt solutions may also corrode metal pipes. Last but not least, high conductivity and the formation of galvanic elements are responsible for the much feared pitting corrosion.
Plastics are therefore almost predestined for applications of this kind in addition to being more economical and easier to process.
Individual differences must be considered
Depending on the type of chemical and its concentration, the prevailing application conditions such as pressure, temperature or other environmental variables,the selection of one particular plastic must be an individual decision.
This decision will not only affect the selection of the type of pipe, but also of the connection elements, seals, fittings and measuring instruments for the particular application. Many decisions for the standard range of applications can be made quickly and easily. GF Piping Systems can base these decisions on proven material expertise and many years of experience.
More difficult are decisions for “exotic” applications or borderline applications. In these cases, the performance capacity of a system must be planned and designed more precisely or a possible working life for the pipeline expressly stipulated.
In principle this rule applies: the more information – for example with regard to pressure, temperature, a precise specification of the medium to be conveyed, the environmental conditions, the pipe diameter – we receive from the client, the easier it is for us to make a recommendation. One help in this area is provided by resistance lists. Consistency lists are a great help here. However, even from these, we can deduct only a possible material stability tendency, in particular for borderline applications.
We would therefore recommend an in-depth discussion with our GF Piping Systems experts during the planning phase of every project. If we can rule out mistakes during conception, this will of course have a positive effect during the realisation of the respective piping system, and will therefore also have an effect on the final economic viability of the project.
Large range of material specific solutions
The traditional solar cell production process uses PROGREF Plus pipes for the transport of deionised/specified water applications. Chemical process media are transported by means of CONTAIN-IT Plus twin-pipe systems consisting of an external protection line and an internal line for conveying the fluids, in accordance with the SYGEF standard, as well as PFA systems, whilst waste disposal pipelines comply with the PROGEF standard and are made from PE, PVC and PVC-C. However, individually concepted client-specific solutions are also sometimes created within this sector.
With respect to the fast growing thin-film production technology, most leading manufacturers rely on SYGEF and PROGEF systems for their deionised water supply and use PE pipes with large diameters, for example for the removal of cooling media from coating plants,whilst PP, PVDF and PFA systems are utilised for conveying highly purified fluids.
Increased security for aggressive media: CONTAIN-IT Plus
Responsible ecological awareness and an increased need for security are playing an ever more important role in our world today.
The risk of personal injury and damage to property and also environmental pollution caused by the discharge of fluids have motivated GF Piping Systems to create suitable systems for the reduction of these potential hazards.
Plant safety during the transport of hazardous materials that pose a risk to people, the environment and the water system necessitates a piping system that fulfils the comprehensive requirements of chemical resistance and guarantees the best possible detection and containment of leaks. Proven and approved connection technologies that are easy to install form an important part of a problem-free production process. The twin-pipe system CONTAIN-IT Plus consists of an external protection line that reliably contains possible fluid leaks from the internal line and acts as a leak monitoring chamber until the leak has been found and repaired. It is also possible to supply fluids via the external line in order to stabilise the temperature of the medium contained within the internal line.
Both the internal and the protection line represent proven, quality assured pressure pipeline systems, the use of which has remained unchanged. The respective connection technology wholly complies with the relevant guidelines for the construction of pressurised pipelines.
The raw material for the production of the internal line can be selected at will to suit the chemical resistance requirements of the application.
Alternative connection techniques
In addition to conventional connection technologies, GF Piping Systems offers two further welding processes that are particularly well suited for the connection of piping systems for the solar industry. These are the infrared welding process known as IR Plus, where all components to be connected are heated in a contact-free way and are then welded under joining pressure in the absence of any additional materials. Contamination and inhomogeneity can be prevented in this way, whilst the size of the weld seam is kept to a minimum by adjusting the joining path or omitting the matching process. The joining path adjustment facility also allows excellent reproducibility of the weld connections.
The WNF-Plus process, which supplies heat energy by means of open channel heater elements in a defined way and supports the inside of the weld zone with the aid of an elastic pressure component, therefore preventing the formation of weld seams, is particularly suitable for welding SYGEF, PVDF and PROGEF PP piping systems. The molten thermoplastic mass is maintained under controlled pressure and guarantees the best possible homogenous welding of the plastic components in this way.
Dead spots will not be created and the surface of the weld will be similar to that of the pipe itself, namely without seams or grooves.
The right material for every medium
The selection of materials for conveying media during the production of photovoltaic components will depend to a large degree on the relevant process. Standardised material solutions will therefore tend to be the exception. Instead, piping systems will have to be designed individually depending on the media. Customer service based on individual requirements is therefore absolutely essential during the entire project phase as well as for the after sales service within this market sector. Only in this way can we create durable pipeline systems that will transport all media reliably and therefore ensure a problem-free production process.
Authors:
Hans Jörg Sommer, Head of Chemical / Mechanical Advises and Claims, GF Piping Systems, Schaffhausen (Switzerland)
Hanspeter Mueller, Market Segment Microelectronics, GF Piping Systems, Schaffhausen (Switzerland)
Picture caption CONTAIN-IT Plus:
Twin-pipe system for absolute security during the transport of hazardous and ecologically harmful media.
(Picture GF Piping Systems, 2009)
Picture caption PROGEF Plus:
The PROGEF Plus system offers the necessary quality and also better leach-out values for DI (deionised) and UPW (ultra pure) water applications than any PVC could ever provide.
(Picture GF Piping Systems, 2009)
Picture caption SYGEF Standard:
The PVDF system from GF Piping Systems offers the best value for money for use with critical chemicals.
(Picture GF Piping Systems, 2009)
Picture caption production:
The special production environments of the photovoltaics industry necessitate individually designed piping systems.
(Picture GF Piping Systems)
Picture caption First Intel – UPW-UF:
Use of GF Piping Systems for UPW (ultra pure water) and UF (ultra-filtration) at an existing photovoltaics production facility.
(Picture GF Piping Systems, 2009)
Georg Fischer – Adding Quality to People`s Lives
GF Piping Systems is one of the three core businesses of the Georg Fischer Corporation and a leading supplier of piping systems in plastic and metal with global market presence. Connecting technology, fittings, valves, measuring devices and pipes are used for water conveyance and treatment as well as the transport of liquids and gases for industrial purposes. GF Piping Systems provides innovative, engineered solutions for the segments building technology, chemical process industry, food & beverage, microelectronics, ship building, water and gas utilities and water treatment. Sales companies in more than 25 countries and representatives in another 80 countries ensure customer support 24 hours a day. Production sites in Europe, Asia and the US are near the customers and meet local requirements. The Georg Fischer headquarters is based since its foundation in 1802 in Schaffhausen, Switzerland.
Key figures GF Piping Systems 2008
More than 4200 employees worldwide
1066 MCHF sales
80 MCHF EBIT
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