Burning coal doesn’t just pollute the environment and harm people’s health -- it’s a huge drain on the world’s increasingly strained supply of freshwater.
The world’s coal-fired power plants use enough water to meet the basic water requirements of 1 billion people, according to a Greenpeace report released late Monday. Making matters worse, 25 percent of the world’s coal-fired power plants -- there are about 8,400 already, and an additional 2,700 planned -- are in areas where freshwater is being used faster than it is replenished.
“Governments must recognize that replacing coal with renewable energy will not only help them deliver on their climate agreements, but also deliver huge water savings,” Iris Cheng, an author of the report, said in a statement.
Water is a crucial part of coal-fired power at every stage, from mining to burning to waste treatment. In total, the coal industry consumes 7 percent of the world’s water, according to the report. That amount could double over the next 20 years if every proposed coal-fired power plant ends up getting built.
An average coal plant "can withdraw enough water to suck dry an Olympic-sized swimming pool roughly every three minutes," the report says.
In some places, coal’s water use is particularly intense. For instance, the coal industry in China consumes about 20 percent of the country's water, according to Jennifer Turner, director of the China Environment Forum at the Woodrow Wilson Center. Turner is unaffiliated with the Greenpeace report, but has written extensively on water and energy issues in China.
Turner told HuffPost that China’s Ministry of Water Resources has produced long, data-heavy reports that back up the anecdotal evidence that environmentalists have been preaching.
And China's not alone. In the U.S., 38 percent of all freshwater use goes to power plants. The vast majority of that water is returned to rivers and lakes, after it has been used to cool power generators. (China and the U.S. are now working together to study ways to reduce the energy sector’s water use.)
Eventually, some places in the world may have to stop building coal-fired power plants because they don’t have enough water.
People usually talk about China's coal problem in terms of the horrendous air pollution, said Turner. But "the air pollution is infinitely more solvable. ... It appears when you look at the numbers, [coal development is] impossible in the long run. Northern China just does not have the water to continue the coal development that they’ve had in the books."
Coal's massive water use is gaining attention as an under-appreciated reason renewable energy sources like wind and solar are becoming more competitive with fossil fuels. Renewable energy is not just lower carbon. It also uses far less water than non-renewable sources.
Wind power barely uses any water. Solar panels use some -- during the manufacturing process, and to clean the panels once they have been installed -- but far less than for coal or other fossil fuels, according to David Rodgers, an energy efficiency and renewable energy researcher at the Global Environment Facility.
A shift to renewables would allow much more of the planet's water to be used for agriculture to feed the growing population, rather than energy.
“Around the globe there is a recognition that energy, water, and food are inextricably linked,” Rodgers said.