The extraction of the methane gas from the bed of Lake Kivu is not likely to affect the eco-system of the lake and the surrounding areas as had been feared by some experts.
A study carried out by a joint Swiss-Rwandan-Congolese research project indicated that the natural stratification of Lake Kivu was unique and would not be affected in a way by the impending methane gas exploitation.
“From our research, the lake is very stable at the moment and far from saturation. We tried to contribute to maintaining the lake at a good state ensuring proper means of extracting gas for power production,” said Martin Schmid, a researcher from the Swiss Federal Institute of Aquatic Science and Technology (Eawag).
This paints a positive outlook on the methane gas extraction project that is seen to setup the country’s target power of 1,000MW by 2017 to meet the demand of the fast-growing economy that is expected to hit middle income status by 2020.
“The accumulation of gases has made Lake Kivu the only lake in the world with enough quantities of methane concentration that could be used for large-scale power production,” Schmid said.
The gas extraction is cost-effective because once the gas-rich water is pumped up, the dissolved gases (primarily carbon dioxide, hydrogen sulfide and methane) begin to bubble out as the water pressure gets lower.
Schmid noted that to keep the stratification of the lake as it is, power plants should be built to produce not more than 250kW. He added that if the Kibuye Power 1 pilot project (KP1) had been on a large scale, it would have negatively affected the lake’s stratification.
Methane gas is targeted to increase the power on the national grid by 100 mega watts to be produced by Contour Global’s Kivu watt project. Rwanda currently produces 110MW for the national power grid.
Gashugi Elisee, from the Applied Chemistry department at Kigali Institute of Science and Technology, which was part of the study, said the survey was aimed at further; understanding of the dynamics of Lake Kivu for future management.
“The team of experts has done their job and it is now up to us and the government to prevent situations like the one where 1,700 civilians suffocated near Cameroon’s Lake Nyos in 1987,” he said
Rwanda’s methane gas reserves in the country’s biggest lake are estimated at around 55 billion cubic meters, dissolved in deep waters at 300 metres with an estimated regeneration rate of about 120 million cubic meters every year.
The Swiss research recommended regular monitoring of the lake’s behavioral changes given the fact that it had volcanic eruptions in the past 5,000 years. This could prompt another eruption in the near future.
“Beneath the lake, there are both warm and cold springs that inhibit it from mixing,” he said
He adds: “This is the same fact that allowed nutrients and gases, including methane, to accumulate in the deep water over several centuries.”
The government set up a lake monitoring team that ensures that the extraction of gases doesn’t interfere with the eco-system and the environment, giving the extraction project a green light.
Some experts are even arguing that the extraction would indeed reduce the dangers of lake explosions.