Paying a tax on IQ hehe
①Energy density is low. Although the total amount of energy that the sun projects onto the earth is extremely huge, because the earth's surface area is also very large and most of the earth's surface is covered by oceans, the solar energy that can actually reaching the Earth's surface is only about 10% of the energy of solar radiation reaching the Earth, resulting in Earth units. The amount of solar energy that can be directly obtained from the area is less. Usually expressed in terms of solar irradiation, the highest irradiation value on the Earth's surface is about 1.2 kW/㎡, and it is less than 1 kW/㎡ in most regions and during most hours of sunlight. Using solar energy is actually about collecting and using low density energy.
②It covers a large area. Due toDue to the low energy density of solar energy, the photovoltaic power generation system occupies a large area. Each 10 kW of photovoltaic power generation requires an area of about 100 square meters, and the average power generation per square meter is 100 W. With the maturity and development of integrated photovoltaic power generation technology To buildings, more and more photovoltaic power generation systems can use the roofs and facades of buildings and structures, which will gradually overcome the lack of large floor area for photovoltaic power generation.
③The conversion efficiency is low. The basic unit of photovoltaic energy production is the solar cell module. Conversion efficiency of photovoltaic power generation refers to the ratio of light energy converted to electrical energy. Currentlyle, the conversion efficiency of crystalline silicon photovoltaic cells is 13-17%, while that of amorphous silicon photovoltaic cells is only 5-8%. Since the photoelectric conversion efficiency is too low, the power density of photovoltaic power generation is low, which makes it difficult to form a high-power power generation system. Therefore, the low conversion efficiency of solar cells constitutes a bottleneck hindering the large-scale promotion of photovoltaic power generation.
④ Intermittent work. On the Earth's surface, photovoltaic power generation systems can only produce electricity during the day and cannot produce electricity at night. Unless there is no distinction between day and night in space, solar cells can produce electricity continuously, whichi is incompatible with people's electricity. needs.
⑤Significantly affected by climatic and environmental factors. The energy of solar photovoltaic power generation comes directly from sunlight, and solar radiation on the Earth's surface is greatly affected by climate. Long-term rain, snow, cloudy days, foggy days and even cloud changes will seriously affect the power generation status. the system. In addition, environmental factors also have a great influence. The most important point is that particles (such as dust) in the air will settle on the surface of the solar cell module, blocking part of the light, which will reduce the conversion efficiency of the module. cell module. This leads to reduced power output and even damage to the battery panels.
⑥ Strong regional dependence. Differents geographical situations and different climates lead to large differences in solar resources depending on the region. Photovoltaic power generation systems will only be effective if they are applied in areas rich in solar energy resources.
⑦The cost of the system is high. Due to the low efficiency of photovoltaic solar power generation, the cost of photovoltaic power generation remains several times higher than that of other conventional electricity generation methods (such as thermal and hydroelectricity), which constitutes the most important factor limiting its widespread application. . However, it should also be noted that with the continuous expansion of solar cell production capacity and the continuous improvement of photoelectric conversion efficiency of cells, the cost of photovoltaic power generation systems has also increased.mined very quickly. Solar cell module pricesOver the past few decades, the price has fallen from more than 70 US dollars per watt to the current level of around 2 US dollars per watt.
⑧The manufacturing process for crystalline silicon cells is very polluting and energy-consuming. The main raw material of crystalline silicon cells is pure silicon. Silicon is the most abundant element on earth after oxygen, and its main form is sand (sio2). The step-by-step transformation of silica sand into crystalline silicon with purity above 99.9999% requires multiple chemical and physical processes, which not only consume a lot of energy, but also cause some environmental pollution.
In terms of pure system construction, water photovoltaic systems are mainly divided into water pile type and floating platform type.you to water.
1. Since the construction of the foundation of the water pile photovoltaic system is more difficult, the cost will also increase to a certain extent. (For example, pump water, then drive the stakes, then attach the support)
2. The advantages and disadvantages of floating water photovoltaics are as follows:
1. the advantages are as follows:
< p>①Save land use: Built on water, it does not occupy land resources and can reduce land acquisition costs.② Increase power generation: Water has a cooling effect on photovoltaic modules, which can suppress the increase in surface temperature of modules, thereby achieving power generation higher. According to a comparative analysis of experiments carried out at a large-scale floating photovoltaic power plant in Hyogo Prefecture, Japan, the panel's electricity productionu increased by about 14% due to the cooling effect of the water surface.
③ Reduce evaporation and algae reproduction: Covering solar panels on the water surface can theoretically reduce water evaporation and inhibit algae reproduction in water, which is beneficial for the protection of water resources.
④ Convenient operation and maintenance: Photovoltaic power plants are built in water, which can reduce dust pollution on components and facilitate cleaning of components. At the same time, it is difficult for users and animals to access the components. which can effectively prevent people and animals from damaging the components.
⑤ Tourism benefits: The photovoltaic modules carefully arranged on the vast water surface can be used as a unique attraction and become a landscape in the area, bringing benefitstourist attractions.
⑥ Avoid shading of modules: Compared with land, the water surface is relatively open, which can effectively prevent modules from being blocked by mountains, woods, etc. . The solar irradiation area is uniform and the lighting duration is long.
⑦ Reduce the cost of the tracking system: The angles and spacing of the components are consistent, making it easier to install and operate the solar tracking system. There is no need to install a two-axis tracking system for each. solar panel, which greatly reduces the cost of the tracking system.
⑧Cost saving: No foundation and component supports are required, saving the cost of foundation and supports and reducing costs.
⑨ Convenient consumption: Built in waters near villages and towns, it can be consumed nearby, reducing adverse factorssuch as network connection difficulties and power outages, and improving efficiency.
2. There are some disadvantages:
① High requirements for floating equipment: floating water photovoltaics requires floating equipment to support the photovoltaic panels, and the floating frame has corrosion resistance, low density , and frost heave resistance, wind and wave resistance, service life, bearing capacity, etc. all have higher demands.
②The site selection requirements are high: the site of the floating water photovoltaic farm should be selected in a wider area, stable runoff, low wind speed, good lighting conditions, small changes water level, good development conditions, no large-scale shipping, ecologically non-sensitive areas and other waters.
③There are many factors insome: strong winds, water level, ice and other factors have a greater impact. At the same time, it is necessary to monitor whether photovoltaic modules have adverse effects on water. quality, fish, plants, etc.
④ Construction difficulty: Many factors need to be considered during the construction process. It is difficult to use a large number of heavy machines for high-efficiency construction in water operations. The process requirements are relatively higher. and the construction period is also increased accordingly. There are many jobs that require diving or being on a boat. Balance and safety must be considered during operations on board, and facilities such as swimming pools and dams must not be damaged.