London (CNN Business) Solar energy in hundreds of Chinese cities is now cheaper than electricity supplied by the national grid, and it can even compete with coal-fired power in 75 of them, a new study has found.

Some 344 Chinese cities were found to have solar systems producing energy at lower prices than the grid, without any subsidies, according to the research published in the journal Nature Energy. That could encourage further investment in renewable energy, according to the authors.

China has made huge progress in developing solar projects and pledged to invest 2.5 trillion yuan ($367 billion) in renewable power generation — solar, wind, hydro and nuclear — from 2017-2020.

China is investing heavily in renewable energy.

Solar can also compete on price with electricity produced solely from coal in around 22% of these cities, according to the research team led by Jinyue Yan from the Royal Institute of Technology in Stockholm, Sweden.

China has long relied on coal to meet its energy needs, but has started to close mines and restrict the construction of new coal power plants in recent years, particularly in heavily polluted regions. Nevertheless, it still accounts for 59% of the country's consumption, according to Reuters.

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