Glass and Solar Energy
Glass has an important role to play in the development of the growing Solar Energy sector. We supply products for all three of the leading technologies, converting power from the sun into clean renewable energy.
Depending on the type, a photovoltaic panel will typically roduce enough power in around two years to offset the energy used in manufacture. In other words, during its life cycle, a solar panel can produce over 15 times the amount of energy used to make it.
Global Photovoltaic (PV) continued its growth trend in 2011 and PV markets again grew faster than anyone had expected, both in Europe and around the world. This was in the main due to the reduced cost of solar electricity, but it was also driven in part by our technological advances, helping our customers manufacture increasingly efficient modules.
Glass is an integral and important element of photovoltaic solar panels. To increase efficiency, low-iron glass, which demands special raw materials, but providers a higher energy transmission than ordinary glass, is increasingly specified. Anti-reflective coatings can also increase the amount of usable solar energy. Our high-quality products are used in the three leading solar technologies aimed at converting solar energy into electricity: thin film photovoltaics, crystalline silicon photovoltaics and concentrated solar power applications.
In addition to the generation of electricity, our glass products are also used in solar applications that generate hot water. We have been closely associated with the leading companies within the crystalline silicon and thin film photovoltaics industries for a long time. This collaboration has come about, in part, as a result of the historical expertise in on-line coating of both Pilkington and NSG which has enabled us to become the worldwide leading producer of high-quality, high-volume Transparent Conductive Oxide (TCO) glass, with manufacturing sites in all main regions. We have been a technological leader in low-iron glass compositions for 25 years.
Glass is an integral and important element of solar modules, used to convert solar energy into electricity. In traditional photovoltaics, the solar cells may be encapsulated using toughened high-transmission glass, which protects the cells from the elements.
During its life cycle, a solar panel can produce over 15 times the amount of energy used to make it. Increasingly, electrically-conductive glass is used in photovoltaic modules as the front contact of the solar cell, to form a system which generates a direct electrical current.
Besides Europe, increasing markets like Japan, China and USA are expected to take an important role in the solar segment. In particular Japan has decided to subsidize officially solar energy generation via Feed-In-Tariffs (FIT) this year and renewable energy is a vital part of the Chinese governmental 5-year plan. US government schemes designed to encourage ‘green’ industries also play an important part in establishing renewable technologies.
Our products support the three leading solar energy technologies. Competitive Levelized-Cost-Of-Energy (LCOE) of PV is increasingly playing a role in encouraging solar generation. Feed-in tariffs in countries such as Germany, Spain, Italy and Greece are becoming less important. However, in emerging economies PV is increasingly being seen as part of the solution to cover the growing energy demand.
Thin film photovoltaic solar modules
Thin film photovoltaic modules produce power at low cost per watt. They are ideal for large scale solar farms, as well as Building Integrated Photovoltaic applications (BIPV). They benefit from generating consistent power, not only at elevated temperatures, but also on cloudy, overcast days and at low sun angles.
Thin film photovoltaic modules consist of a stack of extremely thin photosensitive layers sandwiched between a top TCO coating and a back contact. The 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.
With our advanced technology, coating properties can be ‘tuned’ to a wide variety of Thin Film PV technologies, including silicon and cadmium telluride-based.
Crystalline photovoltaic solar modules
Developed from the microelectronics technology industry, crystalline silicon (c-Si) is the most widely used solar technology. Due to their high efficiency, crystalline silicon modules are best suited to applications where space is at a premium.
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 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™.
Concentrated solar power applications
Concentrated solar power technology uses mirrors to concentrate sunlight. The high performance mirrors are manufactured using metallic reflective coatings and weather protective paints deposited onto very high-performance low-iron float glass. Further developments of CSP cells operating with high transmissible low iron float glasses like Pilkington Optiwhite™ S will be seen in the CSP segment. Pilkington Optiwhite™ S is an ultra-clear float glass with very low-iron content and its high solar energy transmittance makes it ideal as a base substrate for mirrors used in concentrated solar power applications.