Do you know what is the disadvantage of solar energy photovoltaic power generation?

Solar photovoltaic power generation also has its shortcomings and defects, sums up the following points. (1) the energy density is low. Although the total energy of the sun on the earth is enormous, but because of the earth's surface area is big, and most of the earth's surface is covered by sea,

solar photovoltaic power generation also has its shortcomings and the insufficiency, can be summarized as follows. ( 1) Low energy density. Although the sun to the earth's total energy is very big, but as a result of the earth's surface area is large, and most of the earth's surface is covered by sea, can really reach the surface of the land of the solar energy accounted for only about 10% of the radiation energy, within the scope of the sun, the earth caused per unit land area can direct access to solar energy to reduce. Usually with a solar irradiance, the earth's surface irradiance high value is about 1. 2 kw / ㎡, in most areas and most of the sunshine time is less than 1 kw / ㎡. The use of solar energy is, in fact, collection and utilization of low energy density. ( 2) Covering an area of large. As a result of the solar energy density low, photovoltaic power generation system of the area will be very big, every 10 kw photovoltaic area of about 100 ㎡, the average power of 100 w per square metre. With the maturity and development of photovoltaic building integrated power generation technology, a growing number of photovoltaic power generation system can make use of buildings and structures of the roof and facade, it will gradually overcome the lack of photovoltaic covers an area of large. (3) conversion efficiency is low. Photovoltaic power generation is the basic unit of solar battery components. The conversion efficiency of photovoltaic power generation refers to the ratio of light energy to electrical energy. At present, the crystalline silicon photovoltaic conversion efficiency of 13% ~ 17%, and amorphous silicon photovoltaic cell conversion efficiency is only 5% ~ 8%. Due to the photoelectric conversion efficiency is too low, photovoltaic power density is low, difficult to form a high power generating system. The solar cell conversion efficiency is low, therefore, is a large-scale promotion of photovoltaic bottlenecks. (4) the intermittent work. On the surface of the earth, photovoltaic power generation systems can only generate electricity during the day, and not in power at night. Solar cells can continuous production, unless there is a difference in space, day and night, it's not meet people's demand for electricity. (5) affected by the climate and environment factors. Solar photovoltaic energy from the sun directly, and the sun is highly affected by the climate of the earth's surface. Rain, snow, cloud, fog, and even cloud long-term change will seriously affect the state of power system. In addition, environmental factors also have great influence. The most prominent is the air particles in the body, Such as dust) On the surface of the solar cell components, blocking the light. This will reduce the conversion efficiency of the battery module, which leads to the electricity generation to reduce, or even damage the panels. 6. Strong regional dependence. Different geographical location and climate makes sunshine resources is very different in different areas. Photovoltaic power generation system is only used in the solar energy resource-rich regions can work well. All landowners system cost is high. Due to the low efficiency of solar photovoltaic power generation, so far, the cost of photovoltaic power generation is still the way other conventional power generation ( Such as thermal power and hydropower) Several times, this is the main factor that restricted its wide application. Also should be noted that, however, with the expansion of the solar cell production capacity and battery photoelectric conversion efficiency enhances unceasingly, the cost of photovoltaic power generation system is in rapid decline. For decades, the price of the solar energy battery components has fallen from more than $70 per watt to $2 per watt.