2008 sales: $164 billion
China's biggest power company oversees energy lines across the entire country -- reaching more than 1 billion people.
In a bid to reduce its dependence on coal and cut carbon dioxide emissions, State Grid announced plans this year to build a smart grid by 2020. The plan could also lead to State Grid providing more sustainable energy.
Last year the high price of coal used in the company's power plants led to rolling power shortages in the country, but long-term prospects for State Grid look promising: China's power demand and supply are expected to double by 2020.
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