More than six decades ago, three American scientists invented the silicon photovoltaic cell at the Bell Labs in New Jersey, thus laying the basis for most modern solar power systems.

After years of development, China is now the world's largest manufacturer of solar panels and is also the world's largest market for both photovoltaic and solar thermal energy, with more than 60 percent of the world's solar panels made in the country.

It is also home to numerous sizable solar farms, including the Longyangxia dam solar park located in Qinghai province that consists of 4 million solar panels and generates around 220-gigawatt-hours of electricity per year, which can power 200,000 households.

According to China's National Energy Administration, solar PV installations reached 52.83 gW in 2017, up from 34.54 gW in 2016, accounting for about 50 percent of expected global solar demand last year.

So, why is China, and not the US, the global leader now in solar power?

One of the reasons is clear government policy. As demand for energy, and environmental challenges, keeps rising, China is striving to build a greener energy mix with more investment flowing into the clean energy sector.

To be sure, the more polluting coal still accounts for the lion's share in China's energy mix. But, cleaning up the country's energy mix has always been a key policy objective for the government. According to the NEA, China will add over 110 million kilowatts of solar power by 2020.

Another reason for the rise of China to the top of the global solar power industry is the size of the country's energy demand.

China is the largest car market in the world. So, if China decides to put up even just 5 percent of its installed capacity using solar, it would be huge relative to the scene in other countries.

The Chinese government has decided to push through with zero-carbon electricity generation and solar is definitely one of the major clean energy pillars. Other clean energy sources like hydro capacity in China cannot grow much because of the main resources have already been exploited. The nuclear power industry still sees a bottleneck in terms of public recognition or public acceptance, given the attendant security concerns or fears.

Many Chinese companies are also making headlines for record-breaking solar conversion efficiencies, which means more solar energy can be converted into electricity, while identifying promising technologies and finding ways to produce them on a large scale.

Znshine Solar of China has come up with a series of independently developed graphene-coated PV modules to improve efficiency and cut costs in converting light into electricity.

Despite the government's slashing of subsidies for the country's solar firms, it might be just a few years before solar becomes cheap enough to build confidently, without any subsidy, on the back of technological advances.