Ensuring energy and water security: a challenge for Vietnam

Ensuring energy and water security is a challenge for Vietnam

During coal exploitation, a large volume of groundwater is extracted from the ground to allow access to coal mines. A lot of water is needed to reduce the risk of fire or explosions. 

This affects the hydrogeological characteristics of the area, lowering the underground water level, draining local wells and affecting rivers.

According to the General Department of Geology and Minerals of Vietnam, to produce 1 ton of coal, it is necessary to remove 8-10 cubic meters of soil and discharge 1-3 cubic meters of waste water. 

In 2006, the coal mines managed by Vinacomin discharged 182.6 million cubic meters of waste rock and soil and 70 million cubic meters of waste water, causing serious pollution in some areas of Quang Ninh province. 

Acid leaking is one of the most serious effects of coal mining on the environment, especially in the dry season. 

When water comes into contact with exposed rocks after the exploitation process, heavy metals such as aluminum, arsenic and mercury are released in the environment. 

The acid leaking from mines contaminates both groundwater and surface water, destroying the aquatic ecosystem as well as drinking water sources and water used for agriculture. This continues even after the mine is no longer exploited.

Vietnam has about 200 coal mines with total reserves of nearly 8 billion tons, mainly in the northern provinces, especially Quang Ninh. Every year, 15-20 million tons of coal are mined in the province. 

When the coal is exposed to the environment, pyrite will contact water and air and form sulphuric acid (H2SO4). The water from coal mines carries H2SO4 into rivers and cause acidification to rivers. 

Coal-fired power generation requires a large amount of water for cooling. A 500 MW coal-fired plant will absorb a volume of water big enough to fill an Olympic-sized swimming pool every 3.5 minutes. 

A typical coal-fired power plant with an average capacity of 1200 MW consumes about 4.7 million cubic meters of water per day for cooling, about four times higher than the water expected to be consumed by the entire city of Hanoi by 2020.

Meanwhile, the electricity output from coal-fired thermal power will be increasing in the future. 

In 2015, thermopower plants accounted for 34.5 percent (56.5 billion kwh) of total electricity output, while the figure is predicted to rise to 53 percent (304 billion kwh) by 2030.