Why can't solar photovoltaic power generation large-scale promotion

The fundamental problem is that the large solar power technology is still immature, now the world's largest solar power station is only 4. 60000 kilowatts, and includes a series of problems to solve. The fundamental problem is that the large solar power technology is still immature, now the world's largest solar power station is only 4. 60000 kilowatts, and includes a series of problems to solve. All solar power plants can say now only have demonstration effect, and is not capable of large-scale promotion of the economic value. Another of the most successful German solar roof plan, LED street light, is indeed a good way to mobilize the public to do solar power. Its basic plan, paid for by individuals on their roof to build solar power device, the electricity by the national high price to buy all made by transmission back to the grid, a few years down can recover all costs. So, California, USA, also proposed the same solar roof plan. Plan once completed, known as the 'sunshine state' of the California every year will get 3 million kilowatts of clean electricity, will reduce 3 million tons of greenhouse gas emissions at the same time, the exhaust from the equivalent of 1 million cars. But Chinese is hard to promote the solar roof plan, this is because most of China's ability to build solar rooftop middle class live in a high-rise apartment in the big cities, most does not have its own roof, a few more wealthy class, although there is a villa, but also most is not living there for a long time, is unlikely to invest to build solar power systems. As for rural although most farmers have their own roofs, but at most has the ability to build their own solar water heater, and less likely to build solar power systems. So, these reasons may explain, why China cannot large-scale promotion of solar photovoltaic power generation.