Photovoltaic grid-connected power generation system is divided into centralized PV grid-connected power generation system and distributed PV grid-connected power generation system. Centralized large-scale grid-connected photovoltaic power station is the state use of desert, mineral waste land, water and other places, centralized construction of large-scale photovoltaic power station, power generation directly connected to the high-voltage transmission system to supply long-distance load, power station investment, long construction period, covers an area of large. Distributed small grid-connected photovoltaic system, is each household using the roof for photovoltaic power generation, for the user's own use, excess power into the public grid, small investment, fast construction, small footprint, policy support and other advantages, is the mainstream of grid-connected photovoltaic power generation in developed countries in Europe.
But large centralized photovoltaic power station, and did not disappear, but in Asia, Africa and Latin America and other third world countries, and some good light conditions in the region, but also doing light centralized ground power station, and also the more to do the larger.
Southern Egypt is building the world's largest solar farm, which has more than 5 million photovoltaic panels; and Benban solar farm near Aswan, with an investment of $4 billion, which can produce up to 1.8 gigawatts of electricity per year. These two mega solar farms generate electricity equivalent to the combined output of two nuclear power plants, almost twice the annual output of the largest power generation facility in the Americas. The Indian state of Gujarat also recently approved the construction of a 5,000-megawatt solar farm.
So, why are large solar farms being developed in many parts of the world?
This is due to both the laws of development of the industry itself and to technological developments. Concentrated power plants will not disappear, centralized and distributed will co-exist in the long term.
First of all, the laws of the industry, PV development is generally centralized, distributed, PV plus storage three stages, the uneven development of PV around the world, the development of the PV industry in the early stages, to rely on government support, this time the government will generally choose to build large power plants, wait until the medium-term stage, many public participation, distributed PV will begin to develop, PV installation reached a certain size, will cause grid instability This is the time when energy storage must be added to continue to develop.
Secondly, the cost of materials, logistics, transportation, construction and installation are very much related to the scale, the larger the scale of the solar power station, the lower the cost of its PV system, some mega PV power station has been cheaper than coal power.
In February 2018, Saudi power plant developer ACWA won the bid for the Sakaka 300MW PV project in the Al Jouf region of northern Saudi Arabia at 2.3417 cents/kWh (RMB 0.16 yuan/kWh), also the lowest winning tariff in the world at the time.
In December 2018, BhadlaSolarPark, one of the largest PV parks in India, won the bid - at a price of Rs 2.44 (RMB 0.24) per kWh. India's power developer HeroFutureEnergies hands to complete, a total of 300MW photovoltaic power plant, scheduled to be completed in March 2019 grid-connected power generation.
Third, the construction cycle of photovoltaic power plant is short. To build a 1000MW power plant, the construction cycle of nuclear power plant may take 10 years, the construction cycle of natural gas power plant takes up to 4 years, while the construction cycle of solar power plant takes only 18 months. For areas with acute power shortages, building a photovoltaic plant is much faster.
Daniel Kirsin, a professor of electrical engineering at the University of Washington, said, "Typically, solar power plants are located in very remote locations, and the surrounding power grid will not be very strong, which will require power companies to strengthen the grid, which can be very expensive."
However, China has solved such infrastructure problems by already building a supergrid that can transmit power over long distances and ensure that no power is wasted.
Moreover, assuming that mankind could build a global supergrid, a solar farm with just 2 percent of the Sahara desert could meet all of the world's energy needs.
