What is the difference between solar power generation, off-grid and grid-connected:
Off-grid system means that the electricity generated by the photovoltaic power generation system is stored in the battery and converted into AC power through the inverter for direct use by the electrical equipment, or directly supplied to the DC electrical equipment without inverter, and is not connected to the grid .
Grid-connected means that photovoltaic power generation is converted to AC through an inverter, and connected to the grid through a boost or direct low-voltage side, and the grid dispatches and uses the electric energy.
What is the principle of photovoltaic off-grid power generation system:
The working principle of off-grid photovoltaic power generation system is very similar to that of grid-connected photovoltaic power generation system. The only difference is that the power output from the off-grid system is directly consumed and used instead of being transmitted to the public grid.
Solar power generation, thermal power generation and photovoltaic power generation. Regardless of production and sales, development speed and development prospects, CSP can not catch up with photovoltaic power generation. It may be that photovoltaic power generation is more popular and there is less exposure to CSP. Generally speaking, solar power generation often refers to solar photovoltaic power generation. Photovoltaic power generation is based on the principle of photovoltaics. Solar cells are used to directly convert solar energy into electrical energy. Whether it is used independently or connected to the grid, the photovoltaic power generation system is mainly composed of solar panels (components). Controller and inverter three Most of the components. They are mainly composed of electronic components. No mechanical parts are involved. Therefore, photovoltaic power generation equipment is extremely refined. Reliable, stable and long life. Installation and maintenance are simple. In theory, photovoltaic power generation technology can be used for any occasion where power is required. Up to spacecraft. Down to household power supplies. As large as megawatt power stations. As small as toys. Photovoltaic power supplies can be ubiquitous. At present, photovoltaic power generation products are mainly used in three aspects: one is to provide power for non-electricity occasions. Mainly Provide electricity for the life and production of residents in the vast areas without electricity. There are microwave relay power supplies, etc. In addition. It also includes some mobile power supplies and backup power supplies, and the second is solar daily electronic products. Such as various solar chargers, solar street lights and solar lawns. The third is grid-connected power generation. This has been widely promoted in developed countries. China`s grid-connected power generation has not yet started. However, in 2008 Beijing [Green Olympics" part of the electricity will be solar power and wind power Power generation provision.
The most basic component of solar photovoltaic power generation is solar cells (sheets). There are monocrystalline silicon, polycrystalline silicon, amorphous silicon and thin-film batteries. At present, monocrystalline and polycrystalline cells are used the most. Amorphous cells are used in some small systems and calculations. The efficiency of domestic crystalline silicon cells is about 10-13%. The efficiency of similar foreign products is about 12-14%. Solar panels composed of one or more solar cells are called photovoltaic modules. In 2002, global solar cells The output of photovoltaic modules is about 600MW. Japan accounts for 45%. The United States 25%. Europe is about 22%. Japan is the fastest growing factor in the photovoltaic industry. In less than 10 years, it surpassed the United States. In 2001, the top 10 in the world There are 4 solar cell manufacturing plants in Japan. They are Sharp. Kyoto Ceramics. Sanyo and Mitsubishi. Most developed countries in Europe and the United States have formulated the "Sunshine Plan". Measures have been taken to encourage residents to install solar power generation systems. For example, partial grants. Interest-free Loans and [seed funds", etc., and purchase surplus solar power in residents` homes at a price several times higher than the ordinary electricity price.
China's solar photovoltaic power generation industry has developed rapidly in recent years. But the overall scale is small. In 2002, the output of solar cells was about SMW. The cumulative installed capacity reached 25MW. Less than 1% of the world. In order to cooperate with the western development, the Chinese government implemented the [ "Sunshine Project". [Chengfeng Project" and [Bright Project", etc.. Use solar power and wind power to solve the electricity consumption of farmers and herdsmen in the vast western regions without electricity. The supporting funds of this project are more than 2 billion yuan. China's photovoltaic power generation The product market is mainly in the west. There are also some products coming out of the day. Such as modules, small systems and daily-use solar electronic products. Because the domestic solar cell wafer output is far from meeting the demand. Many manufacturers import a large number of solar cell packaging modules. In terms of photovoltaic industry. Shenzhen occupies part of the country. Product processing capacity. Product quality and sales have a certain impact at home and abroad. The government should increase support. Make it expand and develop into an industrial cluster. And then become an economic growth point for Shenzhen .
The solar photovoltaic power generation industry is growing rapidly. It is not only because it is a clean energy with many advantages. A more attractive motivation is. In the process of integration of solar energy and buildings. Solar cell modules are more compatible with buildings than solar water heaters. The sun. Battery modules can not only be used as energy equipment. They can also be used as roofing and wall materials. It not only saves power and saves building materials. There are already very good cases abroad. Therefore, the combination of solar photovoltaic power generation technology and construction will have a good economy. Benefits. The future is unlimited.
