Polaris solar PV net news: 2014-scale photovoltaic power plant construction in China will reach 10-12GW, half of global one-fourth. By November, the domestic photovoltaic power stations usher in the start of rush hour. For now, however, has built large-scale PV quality issues particularly concern, which includes large terrestrial power station components Attenuation and snail-line issues such as outbreaks. Zhangjiakou, author of Qinghai, Xinjiang and part of research or the visit to the plant’s owner, that some power stations use well-known brand of component 1-2 component that is serious decay, snail tattoo is a more widespread outbreak.
Beijing Jian Heng certified centers officials said problems of PV at present mainly in equipment, plant design, plant construction and plant operation and maintenance, and so on. Based on 425 plant’s testing found that PV modules there are hot spots, cracked and power problems. A case study of attenuation, 11 field test last year at the Centre of a large-scale ground operation around 1 component, taking into account the uncertainty of the equipment found 50% about components Attenuation between 5%~10%, 30% about components Attenuation over 10%, 8% of component degradation has more than 20%. This means that component generally promise 25 years only decay 20% quality assurance, some products run only 1 year is approaching even beyond the bottom line.
China PV industry two years ago to invest too quickly, and lower the investment threshold, caused the outbreak, followed by bad money drives out good money. Many developers because they do not know what component technology and system of power station technology, purely in pursuit of investment income component that uses a lot of cheap, low quality. Through the domestic power station research, good attenuation of power station, component output attenuation can be done by 0.1% a year, and some components that are not tested, attenuation exceeds 60%. Solar photovoltaic modules of plastic parts is the quality of the short Board. Of junction boxes, in the plastic edge silicone, backplane and EVA film. And EVA film is the weakest part. EVA adhesive film with EVA resins and additives by heating extrusion molding. Because of EVA resin is prone to hydrolysis and produces acetate, acetic acid becomes a component many different power and attenuation of important reasons.
Acetate and glass from the reaction sodium ion leads to power attenuation (attenuation PID), can also be grating induced by Silver oxidation reactions occur in the snail lines. Japan Chemitox by cell observation in soaking in a dilute solution of acetic acid concentration changes in silver gate line proves that acetic acid can be gradually narrowed grating corrosion cells on the surface of a silver.
Experimentally simulated a harsh natural environment, 85 c, 85% humidity and external voltages up to 1000V, aged 96 hours, EVA currently using cheap adhesive film of the attenuation of the PV modules are 20%-60%. This means that domestic production of components if the environment is not a very desirable state of the plant, possibly in significant attenuation within 10 years. Even after 96 hours, or 192 hours of attenuation testing of PV modules is able to guarantee 25 years of life expectancy is unknown. Large temperature difference between morning and night, or near the water’s edge of the PV power station is dangerous, and these venues because the price is low or there is no other purpose tend to be elected into a solar power station.
With the development of PV modules, power users on decay resistance of components in many countries gradually put increasingly stringent performance requirements. Such as PVEL have proposed anti-PID PV modules require 600 hours aging test, while Japan Chemitox presented needs to be retained on the component surface water film cases of PID decay resistant performance of test components. For PV modules snail tattoo problem, there is currently no standard test methods, but most of them are cracked to make the battery status to make components alternating damp heat aging and exposure. EVA film maker EVA recycled snail sheath formed using, do not use use EVA return promised no snail pattern, in fact, this is the only fur on EVA resin performance and know very little about component structure and guaranteed to the blind. Plastic processing will naturally lead to the gradual degradation of itself multiple times, but rarely in EVA film production possibilities of repeated processing EVA resins. Snail lines and cell quality, back panels and water permeability of EVA film selection of formulation and processing technology, components, design and other aspects of relationships. EVA adhesive film to do snails more important is how to do their own resistance resistance to hydrolysis.
PV modules currently used anti-decaying component of the programme to ensure power at 85 degrees c humidity after 96 hours of aging and 1000V 85%, PV module power attenuation is less than 5%. Use excellent new material AG PID decay-resistant EVA film at the domestic and foreign many well-known components in factory testing attenuation of less than 2%. Japan Chemitox decay resistance of water film on the surface of the component tests, high seas and new material PID decay-resistant EVA film AG is an important guarantee for domestic assembly plant passed the test. Which means haiyouwei EVA laminate in the harsh natural environment protection of PV modules have a longer life expectancy.
Power plant service life calculated in accordance with 25, using components of power attenuation attenuation compared to 5% and 0.8%, return on investment is 9.4%. Again, from another angle says, now the best and worst EVA EVA material material, only a difference of 0.03 per cent on the cost per watt, which means generating revenue can completely cover the cost for 3 days. According to United Kingdom Wind&Sun 2.6KW power plant (United Kingdom first distributed power station) and jianfengling, Hainan power plant investigation of plant decay mainly EVA lines caused by lightning hot spots and yellow led, if high-quality EVA, component service life can reach a higher service life for more than 25 years. CQC of technology engineers Zhang Xue think: common of station owners investment think station component cost more low more good, actual such of concept no considered component 25 life, and station of investment returns, station investment party more should concern component quality, and package material in component constitute in the in is important of status, especially EVA material, because used low quality EVA may led to station mass outbreak lightning lines and power attenuation of situation with domestic installed volume growth, increasingly highlight. Owners invest in PV, EVA material selection should be more careful.
I believe that despite the low quality components to reduce the cost per watt of installed capacity, but we have significantly reduced the plant’s service life, power stations not using live attenuated or even ahead of power plant scrapping. Investors should ignore the per watt of power plant construction costs, and focus on cost per kilowatt.