Photovoltaic power generation has hidden concerns but also optimistic about the prospects for development

“The first domestic thermal power generation project, Ordos 50MW project, will be tendered in August.” The spread of this news raised a great deal of attention in the field of new energy. Not long ago, Asia's first tower solar thermal power station jointly developed by the Chinese Academy of Sciences, Huangming Solar Energy Co., Ltd. and Huadian Group was built in Yanqing, Beijing, and will be connected to the grid in September. This is China's first independent intellectual property right at high temperature. Thermal power projects also received the same degree of market attention.

It can be said that CSP has opened its doors in China and officially entered the new energy market. However, people in the industry are divergent about CSP, especially when it comes to comparison with photovoltaic power generation, it is a controversy. Then, in the future of CSP On the road, is the relationship with photovoltaic power generation an enemy? Or friends? From my personal point of view, in the market prospects, I am more optimistic about CSP; even if I coexist with photovoltaic power generation, I believe that this will also be a relationship of “friends” and will use their complementary advantages in the market, not It will be the "enemy" relationship.

Erupted in silence

After years of silence, solar thermal power generation finally broke out. Previously, solar power generation was mainly based on photovoltaic power generation. Photovoltaic power generation is a technology that uses the photovoltaic effect of the semiconductor interface to convert light energy directly into electrical energy. The key element of this technology is solar cells. After the solar cells are encapsulated and protected in series, a large area solar cell module can be formed, and a photovoltaic power generation device can be formed by combining the power controller and other components. Even though photovoltaic power generation has been developed for many years and an industrial chain has been formed in China, there are still some technical problems that have been overcome. For example, the photoelectric conversion rate is low, especially in cloudy weather, the photoelectric conversion rate will be greatly reduced; Second, from the current actual situation, solar panels with photovoltaic or monocrystalline or polycrystalline silicon as the main raw material are positive More and more places are dotted on the roofs and walls of urban buildings and become a so-called “clean and pollution-free” solar power station. However, behind the so-called “green power station”, it has “hidden” a series of high-energy-consuming and highly-polluting production processes. At the same time, the excess production capacity of photovoltaic power generation is a waste of energy and capital.

Photovoltaic power generation, as long as the solar energy gathered, heating the working fluid, driving the turbine generator that can generate electricity. In 1950, the former Soviet Union designed the world's first solar tower power station and built a small experimental device. At present, the first solar thermal power station in Asia is built in Yanqing, Beijing, which is China's first thermal power station with independent intellectual property rights. At present, the power station is about to enter the debugging stage. After the completion of the thermal power station, the annual power generation capacity will reach 2.7 million kWh, and more than 2,300 tons of carbon dioxide will be reduced.

Although China's solar thermal power generation started late, in Spain and the United States, Europe and the United States, solar thermal power generation has already reached a certain scale. Solar thermal power generation is becoming a hot spot for investment in renewable energy in the world. In the 2007 Medium and Long Term Development Plan for Renewable Energy, it was mentioned that in the future, free land such as desert, Gobi, and wasteland will be selected in Inner Mongolia, Gansu, and Xinjiang to build a solar thermal power generation demonstration project by 2020. The total capacity of solar thermal power generation in the country will reach 200,000 kilowatts, which will be comparable to that of photovoltaic power generation. It can be said that a new era of solar thermal power has come.

Technical obstacles

Photovoltaic power generation has a short development time in China. Substantial progress has been made in solar concentrating methods and equipment, high-temperature heat storage and heat storage, power station design, integration, and control. Moreover, the major equipment and components for the construction of solar thermal power stations have been able to produce domestically and a relatively complete industrial chain has been initially formed.

However, it is not enough to study without practice. At present, there is no real demonstration power plant in China. By the end of August, the Yanqing Tower-type solar thermal power station that will be commissioned and connected to the grid will be used for practical applications in China. Vacancies provide an opportunity to make up.

Photo-thermal power VS photovoltaic power generation

Unlike photovoltaic power generation, the scale of photovoltaic power generation can vary from several kilowatts to hundreds of megawatts, but photothermal power generation is a typical scale economy. With the increase in scale, the cost of power generation is lower. In the northwest region where the terrain is open in China, if the large-scale construction will greatly reduce the investment cost of equipment, therefore, solar thermal power generation has a certain advantage in terms of cost.

However, photovoltaic power generation has been developing for a long time in China, and a complete industrial chain has been formed. In a short period of time, photovoltaic power generation can hardly exceed photovoltaic power generation. However, a few years after the development of CSP, the technology is more mature and the field of practice can also make progress. I think CSP will be more market than PV.

However, our ultimate goal is not to let photovoltaics and light and heat be “killed”. It is hoped that the two can complement each other to a certain extent and take their own shortcomings to achieve the goal of “mutual benefit and mutual benefit”. It is our ultimate goal. According to the American "Popular Science" report, Stanford University engineers have recently found a way to use the sun's light and heat to generate electricity, which will enable solar products to achieve three times the efficiency of existing methods, and may be Make solar energy cheap enough to compete with oil. This subversive solar energy utilization method is called "photon enhanced thermal ion radiation", abbreviated as PETE. A team led by Nick Melosh, an associate professor of materials science and engineering at Stanford University, sprayed a thin layer of metallic germanium on a piece of semiconducting material, giving the material the ability to generate electricity using light and heat. Research confirms that this new process will no longer be based on a standard photovoltaic generator system and will produce a reaction similar to photovoltaic power generation under very high temperature conditions, and the higher the temperature, the higher the work efficiency, and the traditional photovoltaic power generation at the temperature As efficiency increases, it gradually decreases.

This breaks the traditional concept of "photovoltaic" and "light-heat", but combines them to complement each other. In the future research field, more new achievements will be exhibited, and more technological achievements will be applied to practice. The goal of “mutual benefit and win-win” for photovoltaic and solar thermal will eventually come true.