Gas from a potentially catastrophic ‘killer lake’ provides 30% of Rwanda’s electricity

A fisherman is catching his nets early within the morning on Lake Kivu. (Photograph by Kay Nietfeld/image alliance by way of Getty Photos)

• Hundreds of years of volcanic exercise has triggered an enormous accumulation of methane and carbon dioxide to dissolve within the depths of Lake Kivu between Rwanda and the Democratic Republic of Congo.
• If triggered, a so-called limnic eruption would trigger giant waves and a toxic fuel cloud that may put the lives of thousands and thousands in danger
• KivuWatt, which says that is the one challenge of its form anyplace on this planet, noticed a chance to faucet these ample gases for power era.

The engineers aboard the floating energy station on Lake Kivu may solely watch nervously because the volcano within the distance erupted violently, sending tremors rumbling by the water beneath them.

It was not the lava capturing from Mount Nyiragongo final Could that spooked them, however the monumental concentrations of doubtless explosive gases inside Kivu, one among Africa’s nice Rift lakes mendacity between Rwanda and the Democratic Republic of Congo.

Flanked by rolling inexperienced hills tumbling into glassy waters, Kivu will not be fairly the image of tranquility it appears, in keeping with Francois Darchambeau from KivuWatt, an organization that extracts fuel from the lake’s waters for electrical energy.

Hundreds of years of volcanic exercise has triggered an enormous accumulation of methane and carbon dioxide to dissolve within the depths of Kivu – sufficient to show monumentally harmful within the uncommon occasion they have been launched.

If triggered, a so-called limnic eruption would trigger “an enormous explosion of fuel from deep waters to the floor” leading to giant waves and a toxic fuel cloud that may put the lives of thousands and thousands in danger, stated Darchambeau, environmental supervisor at KivuWatt.

“That is what we name a killer lake,” the limnologist, or an professional in freshwater programs, instructed AFP.

Solely three such lakes exist on this planet: Kivu, and Lakes Nyos and Monoun in northwest Cameroon.

The latter two skilled limnic eruptions within the Nineteen Eighties, and the larger catastrophe at Nyos suffocated greater than 1,700 folks in a poisonous launch of carbon dioxide.

However these catastrophes occurred in a rural space, whereas some two million folks can be “in danger” of such an identical catastrophe involving Kivu, stated Darchambeau.

In each Rwanda and DR Congo, many stay in concern of the lake’s dangerous potential, and tales abound of swimmers disappearing into its depths after being asphyxiated or pulled below.

World first

The lake, nonetheless, poses each peril and promise.

KivuWatt, which says that is the one challenge of its form anyplace on this planet, noticed a chance to faucet these ample gases for power era.

A 20-minute speedboat journey is required to succeed in KivuWatt’s distinctive floating platform, a compact tangle of pipes and buoys as excessive as a multi-storey constructing moored within the Rwandan a part of Kivu.

With a deafening roar, the ability pumps water saturated with carbon dioxide and methane from round 350 metres to the floor.

Because it rises, the water and fuel separate because the stress modifications.

“It’s like opening a bottle of soda,” stated KivuWatt director Priysham Nundah, who described the challenge as “midway between a thermal and a renewable power plant”.

The extracted methane is distributed by a pipeline to a second facility situated onshore in Rwanda, the place the fuel is reworked into electrical energy.

The carbon dioxide is pumped again into the lake at a exact sufficient depth to make sure the fragile stability will not be upset.

The corporate says it hopes that eradicating methane may over time cut back stress inside the lake, presumably decreasing the danger of a limnic eruption.

‘It was horrifying’

However fears of such a catastrophe have been reawakened when Nyiragongo — an energetic volcano north of Kivu in DR Congo – roared to life in early 2021.

The lava stream killed 32 folks and destroyed a whole bunch of properties, as earthquakes shook the area. A second wave of lava pushed deep into the earth below the lake itself.

From their station, KivuWatt’s engineers watched the sky flip purple and offended.

“It was very horrifying,” stated Nundah.

“When the charges of earthquakes and the frequency of earthquakes began to rise… nobody may actually say what would occur.”

A shutdown was thought of – however the engineers held their nerve.

Suspending operations would have critical penalties for Rwanda: KivuWatt produces round 30 p.c of the annual electrical energy consumed within the East African nation.

American firm ContourGlobal, which owns KivuWatt, launched the Lake Kivu enterprise in 2015 and for a time thought of increasing its capability from 26 to 100 megawatts.

One other firm is exploring the potential of launching its personal 56-megawatt fuel extraction enterprise on the lake. There aren’t any plans within the quick time period for such a challenge on the Congolese aspect.

How lengthy it’ll take to deplete these huge fuel reserves will rely upon the tempo of extraction, stated Martin Schmid, a researcher on the Swiss Institute for Water and Environmental Analysis.

“Simply with KivuWatt alone it’ll take, I do not know, centuries to have actually a discount of methane within the lake,” he stated.