BEIJING, June 22 -- Electricity demand in China, the world's second-biggest energy user, may increase 63 percent between 2009 and 2015 as the economy expands, the State Electricity Regulatory Commission said today.

Consumption may reach 5.86 trillion kilowatt-hours, the power regulator said in a statement on its website. That compares with 3.6 trillion kilowatt-hours last year, based on data from the National Energy Administration published on Jan. 6.

China, the world's fastest-growing major economy, is expected to expand four times faster than the U.S. this year, the United Nations said in December. Energy demand is expected to grow “quickly” as the economy maintains a fast pace of expansion between 2010 and 2020, the regulator said in today's statement

Energy consumption may rise to the equivalent of 4.2 billion metric tons of coal in 2015 and 5 billion tons in 2020, according to the statement. The country's installed power capacity may reach 1.35 billion kilowatts in 2015, it said.