Government policy: that is, the government creates monopoly, such as China's four major banks, two barrels of oil;
Resources: key resources are owned by the enterprise;
Technology and patents: the so-called natural monopoly, such as Microsoft;
The efficiency of solar energy is 30%, and mine is 90%. It is extremely technical and it is difficult to make a breakthrough. As long as they can get patents and it takes a long time for competitors to achieve 90% efficiency, then they can monopolize market production. Of course, the government will not conduct an anti-monopoly investigation on you.