48 Concentrating Photovoltaic Modules Forming Photovoltaic Arrays for Harbin

On September 25, when the photovoltaic array consisting of 48 concentrator PV modules was placed on an open space in the Weihai Campus of Harbin Institute of Technology, the general manager of Shanghai Juheng Solar Energy Co., Ltd. (hereinafter referred to as “Conheng Solar”) Rong Gang's face showed a smile. This is also the first Concentrating Photovoltaic Demonstration Power Plant project in the company's three years of existence, totaling 11.28 kilowatts.

If you summon Suntech, Yingli, and other PV module manufacturers and look at the demonstration plant, perhaps they will dismiss it: “Is this scale too small?”

However, for Rong Gang and other industry players, it is more worth looking forward to focusing on photovoltaics than on polycrystalline silicon.

What is the prospect of concentrating photovoltaics?

Compared to the crystalline silicon and thin-film battery industries, concentrating photovoltaics is not a market that has great enticement, at least for the time being it has not been able to draw a firm conclusion. However, more and more companies have joined the industry, including Boeing, Amonix, Sharp, Practical Instruments, and domestic Sanan Optoelectronics [41.37-5.20%], Fuyang New Energy, Anhui Yingtian New Energy, and Hanlong Group. and many more.

Wang Shitao, director of Polyheng Solar Energy Technology, explained: As the name implies, “spotlight” is to gather sunlight on a small battery. “Our company manufactures concentrated photovoltaic modules, which consist of flat glass optical systems and solar cells. ."

Hou Wentao, a researcher at Xiangcai Securities, said that, in fact, a concentrating photovoltaic power generation system is an electricity generation technology that uses an optical system to collect solar energy on solar cell chips and then uses the photovoltaic effect to convert light energy into electrical energy.

A management staff of the Huadian Group told the reporter of the First Financial Daily that there are different technologies for concentrating photovoltaics, which is similar to the way of polyconstant solar energy and is simply referred to as “transmissive”. He has also contacted another technology, that is, put the solar cell on the lens, through the focus of the secondary reflective surface, and then let the battery chip to achieve photoelectric conversion, this technology has been used by Israeli companies.

Regardless of the subdivision technology, Concentrating Photovoltaic Power has some unmatched advantages of crystalline silicon batteries. In the industry, it is also seen as the third generation of photovoltaic technology that can replace part of the crystalline silicon market (first generation, first The second generation is crystalline silicon and thin film technology, respectively).

Wang Shitao told reporters that the products developed by Congheng Solar now allow the lens area to be 576 times the battery area. “In other words, the area of ​​crystalline silicon of 1000 square centimeters is comparable to that of a solar concentrator like 1 cm by 1 cm.”

In theory, the higher the magnification, the more material the chip can save. "In fact, a battery used in concentrating photovoltaic power generation costs 100 times as much as a crystalline silicon battery. However, if the multiple between the lens and the battery can exceed 300 times, then the cost of the concentrator battery will also be equal to The silicon battery has been leveled. Therefore, companies are researching higher-density concentrating photovoltaic products, which can save more materials." Wang Shitao said that the current domestic Sanan Optoelectronics company can also achieve 529 times.

Another great advantage of concentrated photovoltaic power generation is its extremely high conversion efficiency.

Polyheng Solar revealed that the battery conversion efficiency of this demonstration power plant project established at the Hugong University Weihai campus is about 25%. If it is true, then the efficiency is much higher than the conversion efficiency of all crystalline silicon on the market in China (the current maximum efficiency of crystalline silicon cells is about 18%).

In theory, the conversion efficiency of general concentrating power generation is about 70%. If some impairments are added, the probability of a breakthrough of 30% in the convergence conversion efficiency in the next 1 to 2 years is very high.

Hou Wentao stated that concentrating photovoltaic technology saves raw materials in terms of area, and its cost limit is bound to be lower than crystalline silicon and thin-film batteries. "At present, according to Sunpower's theory, a 35% photoelectric conversion efficiency of battery focusing system may be possible. It is the lowest cost power generation method and it may be the ultimate power generation technology."

The reason why the conversion efficiency of this technology is so high is also related to the nature of the battery. Concentrating photovoltaic power stations will often use "multi-junction three-five" solar cells, it is also known as "strontium gallium arsenide" batteries, is the highest photoelectric conversion efficiency of the battery.

Because its price is very expensive, the earliest use of space and space stations in the space sector to provide energy, the use of the ground is difficult to spread.

In fact, there will be more heat after the spotlight, and this heat can be converted into electricity or hot water. Therefore, concentrating electricity can be easily combined with the use of a solar thermal system.

Why is development slow?

However, after the crystalline silicon battery has occupied more than 80% of the world's photovoltaic power plant market, the concentrating photovoltaic power generation suddenly has a little movement, can not help but confuse people: what exactly is the reason, making the technology now surfaced? ?

In the early 1990s, countries such as Germany, Australia, the United States, and Japan have in fact launched various "solar roofing" programs. However, from the point of view of the spotlight, it is not suitable for roofs. Crystalline silicon is the most suitable product for roofs.

Rong Gang told reporters that concentrating photovoltaic projects are generally placed directly on the ground through a stand. Assuming that they are all installed on the roof, there are difficulties in maintenance and installation.