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As natural disasters go, the limnic eruption -- an explosion of gas from beneath a lake -- of Lake Nyos in Cameroon in 1986 ranks among the most horrifying and bizarre: About 1,700 people and 3,500 livestock were suffocated when a large cloud of CO2 descended silently on their villages.
Lake Kivu, one of Africa's great lakes, which lies on the border of Rwanda and the Democratic Republic of the Congo, poses a similar danger because vast amounts of methane gas and CO2 are buried in its depths. At the same time, rural Rwanda desperately needs more electricity -- only about 6 percent of the nation's 9.7 million people are connected to the electricity grid, according to the government.
To Contour Global, a private company that specializes in power-generation projects in the global south, this is a business opportunity. The company has embarked on an ambitious $325 million plan to extract the methane gas from the lake to provide about 100 megawatts of gas-fired electricity to Rwanda.
To put that in context, total generating capacity in Rwanda is now just 69 megawatts -- about 10 percent of the capacity of a single coal-fired power plant in the U.S.
Recently, I spoke will Bill Fox, senior vice president of Contour Global, who is overseeing the Lake Kivu project. The company, he told me, was founded in 2005 by Joe Brandt, a former executive with the global power generation company AES, and funded by Reservoir Capital, a $4 billion investment fund. Contour Global and Reservoir Capital are based in New York.
Fox, who is 62, spent most of his career in the U.S. before joining Contour Global two years ago. Since then, he has managed a hydroelectric project in Brazil and made four trips to Lake Kivu.![Profile_William Fox[1]](http://www.marcgunther.com/wp-content/uploads/Profile_William-Fox11-150x150.jpg)
"The country, under President Kagame, has a very ambitious goal to increase the electrification rate," Fox told me. "They're going about it in a major way, building transmission and generation."
The technology behind the Lake Kivu project is a bit of a mystery to me but, as Fox explained it, Contour Global will build a gas extraction facility that will be mounted on a big barge. It will then siphon gases to the surface from a depth of about 350 meters.
"If you can picture a champagne bottle that's open, where the bubbles rise to the surface and they drag the liquid with it, that's what's happening in the lake," Fox said.
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Greenwash or Green Energy?
The give-away in the comments by Fox is that the "technology is simple" for gas extraction from Lake Kivu.
It is not, at least not since the legacy method of extraction has been effectively banned. This was because of its severe long-term potential for de-stabilisation of Lake Kivu.
The legacy method which ContourGlobal is planning to use is also a low-recovery method with less than 25% of the available energy (methane) being put to use and more than 75% being released via shallow water to atmosphere and producing a greenhouse gas cloud over the lake.
If this legacy-based method was used exclusively, the lake's useful energy output would probably be limited to 200MW for 40-50 years whereas newer high-tech and efficient methods could produce as much as 1000MW for the next 50 years from the lake.
More damning than this is the effect of the legacy (C-G) method on the lake itself. Firstly the method results in the total mixing of the lakes waters from top to bottom, destroying the multiple density layers that are the best defence mechanism of the lake against gas eruptions in the long-term future, perhaps 2-4 generations from now.
Secondly, the lifting of the deep-waters towards the surface results in a radical increase of nutrients, currently trapped in the deep, into the surface (biozone) layers. These nutrients will rapidly consume all biozone oxygen, leaving the lake as a green, stinking eutrophic soup. Without oxygen, the 60m deep biozone layer no longer converts methane and hydrogen sulfide to their relatively harmless oxidised derivatives. Hydrogen sulphide is toxic and will affect anyone on the lake and anyone near it.
The small fishing industry that relies on algae-eating limnothrassa fish will collapse as they are wiped out with seasonal oxygen depletion.
Whether the lack of fish or the dangers of eruptions is first to chase the fishermen and their small communities away from the lake, there must be a serious concern whether ContourGlobal has embraced the principles of public safety, environmental preservation and social benefit that are supposed to precede the commercial benefits to gas developers on Lake Kivu.
I submit that their story might be more about greenwash, and not green energy. I think Marc Gunther has been sucked unwittingly into supporting a flaky cause here. Dig a little deeper Marc as our research does not support the views expressed in this gloss-over article.