Energy-starved Rwanda in central Africa is looking to put to use the 60 billion cubic meters of methane and 300 billion cubic meters of carbon dioxide dissolved in Lake Kivu, but the pioneering project is a big gamble.
The methane alone could be used to generate 960 megawatts of electricity for both Rwanda and the neighbouring Democratic Republic of Congo.
Removing the gases, which come from nearby volcanic activity and bacteria decomposing organic material in the lake, could also help the country avoid a catastrophe. If pressure of the gases builds up too much, it could cause a limnic eruption, where gas erupts from the lake, killing humans and animals in the vicinity.
Its happened at Kivu at least five times in the last 6,000 years, according to evidence in the sediment of the lake, scientists say.
But, as MIT Technology Review explains, extraction of the gases holds risks of its own.
While the technique is being tried for the first time, it is based on relatively simple rules of physics.
Water will be drawn from 350 metres beneath the surface and as it rises, and the pressure decreases, bubbles of methane and carbon dioxide will begin to form. It is estimated 80% of the methane and 40% of the carbon dioxide will be separated in this way.
