Solar Energy Solar Energy range NSG TEC™ Pilkington Microwhite™ Pilkington Optiwhite™ Pilkington Sunplus™ Moving from hydrocarbon dependency to renewable energy The use of solar energy glass and the NSG Group Over the past few years, legislation has been Glass is an integral and important element of introduced around the world to address the issue of these solar panels. renewable energy, spurred on by the Kyoto protocol Our wide range of high quality products are used and subsequent national targets. It is increasingly in the three leading solar technologies aimed at recognized that a move from hydrocarbons is essential converting solar energy into electricity: as supplies are finite and global warming is a reality. thin film photovoltaics, crystalline silicon photovoltaics and concentrated solar power Solar energy panels offer alternative solutions for applications. a range of energy requirements, from small scale In addition to the generation of electricity, our glass domestic applications to large scale solar power products are also used in solar applications that stations, from cloudy northern rooftops to hot generate hot water. sunny deserts. Solar Energy – the environmentally friendly technology 1 hour of sunshine = 1 year of global energy consumption Renewable and Reliable Greenhouse gases (g/kwh of CO2 equivalent) Coal 900 Oil 850 Gas combined-cycle 400 Biomass 45 Multicrystalline silicon 37 Photovoltaics Cadmium telluride thin film 18 Source: EPIA Wind 11 Source: Juwi Solar Converting solar energy into electricity Thin Film Photovoltaics Characteristics Thin film photovoltaic modules produce power at low cost per watt. They are ideal for large scale solar farms, as well as Building Integrated Photo- voltaic applications (BIPV). They benefit from generating consistent power, not only at elevated temperatures, but also on cloudy, overcast days and at low sun angles. For BIPV applications, thin film modules have excellent aesthetics. They also benefit from a relatively small drop in power output under partial shadowing when compared with crystalline silicon modules. This gives thin film modules greater design flexibility when integrated into the building envelope. Thin film photovoltaic (PV) modules consist of a stack of extremely thin photosensitive layers sandwiched between a top Transparent Conductive Oxide (TCO) coating and a back contact. The VISOLA Source: Kaneka, photovoltaic layers are laminated between a TCO coated front glass such as NSG TEC™, and a low cost backing material, such as standard or thermally strengthened Pilkington Optifloat™ Clear glass. There are a number of thin film photovoltaic a variety of thin films photovoltaic technologies, technologies including amorphous silicon (a-Si), with different haze and conductivity levels. tandem (a-Si/μ-Si) – a combination of amorphous and microcrystalline silicon, cadmium telluride All our NSG TEC™ products are manufactured (CdTe), copper indium (gallium) diselenide (CIS, using a patented chemical vapour deposition process CIGS) and dye-sensitised solar cells (DSSC). to produce a durable, on-line pyrolytic coating a-Si, a-Si/μ-Si, CdTe and DSSC are deposited that may be heat strengthened or fully tempered, directly onto NSG TEC™; CIS and CIGS tend providing complete flexibility for module production. to be deposited onto a molybdenum coated glass substrate. Each of our products within the range is targeted at a particular thin film photovoltaic technology. For a-Si, Our products a-Si/μ-Si, CdTe and DSSC technologies, properties NSG TEC™ is a group of products, including such as light transmittance, TCO conductivity (sheet a comprehensive range of TCO (Transparent resistance) and light trapping (haze) can be optimized Conductive Oxide) coated glass, optimised to suit to meet individual customer requirements. Thin Film Photovoltaics Generic superstrate construction (a-Si, μ-Si, CdTe, etc.) Glass TCO coating Photovoltaic absorbing layers a-Si, µ-Si, CdTe, etc. Back contact Encapsulant Back plate Glass Glass TCO coating TCO coating Amorphous and Photovoltaic absorbing layers microcrystalline silicon Cadmium telluride Photovoltaic absorbing layers Back contact Back contact Generic substrate construction Low iron glass (CIS, CIGS) Encapsulant TCO coating Photovoltaic absorbing layers CIS, CIGS Back contact Blocking layer Back substrate NSG TEC™ Sodium Block is used for CIS/CIGS Our NSG TEC™ products are available in either applications. It includes a sodium barrier layer, standard or low iron glass composition depending which offers manufacturers improved product on the substrate/coating combination. stability and increased process throughput. NSG TEC™ range product features summary: l available on standard clear or low iron glass, l high light transmittance, medium to high depending on the coating type; conductivity, low to high haze properties l durable on-line pyrolitic coating, making the to suit all thin film photovoltaic applications; product easy to transport, store, handle and l coating properties are resistant to heat (i.e. un- process, reducing costs and lead times; affected by very high processing temperature); l sodium blocking performance; l can be fully tempered/toughened or heat l unlimited shelf-life; strengthened without damage to the coating l available in a wide range of thicknesses, or drop in performance; from 2.3 mm to 6 mm. The properties of our main NSG TEC™ products are summarised in the table below: NSG TEC™ A8 NSG TEC™ T11X NSG TEC™ NSG TEC™ A7 NSG TEC™ C10 NSG TEC™ C15 NSG TEC™ A9 NSG TEC™ A9X Sodium Block Light transmittance High High High High High Very High Conductivity High High High Medium High None Haze Medium High Low Low High Very Low Sodium blocking layers Yes Yes Yes Yes Yes Yes Amorphous silicon Cadmium telluride Cadmium telluride Tandem Technologies Amorphous silicon CIS/CIGS DSSC DSSC DSSC Amorphous silicon The NSG TEC™ descriptive names indicate the technology to which the products are most suited as well as the corresponding technical values. Technology Sheet resistance Glass composition A = amorphous silicon (a-Si) NSG TEC™ T = tandem (a-Si/μ-Si) 7 to 15 Ohms/sq X for low iron C = cadmium telluride (CdTe) Pilkington Optiwhite™ may also be used as a base Pilkington Optiwhite™ and Pilkington Optiwhite™ S for TCO deposition, or as a top cover plate for CIS features summary: and CIGS thin film PV. PilkingtonOptiwhite ™ is an l very high light transmittance and solar heat ultra clear float glass with a very low iron content, transmittance; which maximises the solar energy transmittance l consistent lifetime performance following and, therefore, the efficiency of the module. prolonged exposure to the sun (no solarisation); l available in annealed or tempered/toughened Our range of products includes the standard and form; well established low iron Pilkington Optiwhite™ l available in a wide range of cut-sizes and and its new version, developed especially for the jumbo plates, from 2 mm thickness and solar industry, Pilkington Optiwhite™ S, which upwards. offers even greater solar transmission. Crystalline Silicon Photovoltaics Characteristics l multi-crystalline silicon, made by sawing a cast Developed from the microelectronics technology block of silicon first into bars and then into wafers. industry, crystalline silicon (c-Si) is the most widely Mono-crystalline modules typically have higher used solar technology. Due to their high efficiency efficiencies than those of multi-crystalline. crystalline silicon modules are best suited to applications where space is at a premium. In crystalline silicon modules, cells are connected together and then laminated under toughened, high There are two types of crystalline silicon modules: transmission glass to produce reliable, weather l mono-crystalline silicon, produced by slicing resistant modules. wafers from a high-purity single crystal ingot; Crystalline Silicon Photovoltaics using a patterned surface Generic construction Anti-Reflective coating (optional) Low iron patterned glass Encapsulant c-Si cell Back plate Individual cells The glass type normally used for this technology is low iron rolled glass such as Pilkington Sunplus™, often in toughened form, combined with an Anti-Reflective (AR) coating, to ensure that the maximum solar radiation reaches the PV cells. It is also possible to use low iron float glass such as Pilkington Optiwhite™. Our products Pilkington Sunplus™ is a glass specifically developed for use in crystalline silicon modules. This high performance low iron glass has very high solar energy transmittance. When toughened, Pilkington Sunplus™ range features summary: its strength and durability make it the ideal choice l ultra high solar energy transmittance and low for this application. light reflectance; l choice of patterns, either SM or MM to suit Our range of Pilkington Sunplus™ products include: the specific application; l Pilkington Sunplus™ SM: ultra high solar energy l the pyramidal pattern can assist in the lami- transmittance and low light reflectance due to a nating process during module manufacture, combination of a prismatic pyramidal pattern on but can be used on the external surface if one surface (S), and a matt pattern on the other (M); desired; l Pilkington Sunplus™ MM: ultra high solar energy l SM product available with Anti-Reflective transmittance and low light reflectance due to the (AR) coating for optimal solar energy matt pattern surfaces on both sides; conversion; l Pilkington Sunplus™ SM AR: ultra high solar l consistent lifetime performance