Mining Methane In Lake Kivu, Rwanda: An Unusual Source Of Renewable 
Energy June 15th, 2019 by David Zarembka
SNIPPET:
Lake Kivu, between Rwanda and the Democratic Republic of the Congo (called “DRC” by Africanists), is many times larger than the two Camerooning lakes. It is the eighth largest lake in Africa, with a surface area of about 1040 square miles. Two million people live on its shores.
Mount Nyiragongo it 20 miles north of Lake Kivu in the DRC. It has erupted 34 times since 1882. There was a massive eruption of Nyiragongo in January 2002 and its lava flowed all the way into Lake Kivu. There were fears that the lava might set off a limnic explosion. Luckily, it didn’t.
This danger led the Rwanda government to explore the idea of mining the methane in the lake to reduce the possibility of a limnic event. In 2010, KivuWatt, the first methane-extraction platform, was proposed and it went online in 2015 at 26.2 MW of output, which was later increased to 34 MW. Recently, two more platforms have been approved for development, one at 56 MW and the second at 25 MW. When these are in service, this will total 125 MW of power. While this might seem extremely small, Rwanda’s total electricity capacity in 2018 was only 218 MW. The two additional plants will therefore add a significant amount of additional capacity to the country. The estimated 65 cubic kilometers of methane in the lake would last for more than 50 years.
Then in February of this year Rwanda signed a $400 million agreement with a company called Gasmeth Energy to extract methane from the lake and directly bottle the methane gas for direct use by consumers.
This methane gas mining from the bottom of Lake Kivu is an interesting, unusual source of renewable electricity. It is “renewable” because it is already existing, produced by a natural process. The CO2 in the lake is still of great concern, but since Lake Kivu is 200 times the size of Lake Nyos, withdrawing the CO2 from the lake would be a major engineering problem.
full article:https://cleantechnica.com/2019/06/15/mining-methane-in-lake-kivu-rwanda-an-unusual-source-of-renewable-energy/Agelbert COMMENT: To David Zarembka:
I understand and support the human dire need for energy, but this technology unfortunately causes more Greenhouse Gases to be released into the already over burdened heat trapping atmosphere. I have an alternate proposal that you may wish to consider.
Fishing boats on Lake Kivu, 2009
The fish fauna in Lake Kivu is relatively poor with 28 described species, including four introduced species. Lake Kivu
fish stock viability is important to the local economy surrounding the lake. Fish stocks are negatively impacted by the estimated 65 cubic kilometres of CH4 (that If burnt over one year, would give an average power of about 100 gigawatts for the whole period).
Fish require a certain amount of dissolved oxygen in the water in order to survive and thrive. The estimated 256 cubic kilometers of carbon dioxide, which no doubt contributes to to the pH level of about 8.6, also limits the fish biome within the lake.
Since the lake surface area, estimated at some 2,700 km2 (1,040 sq mi), is quite extensive, if they could get a loan from China to put floating solar panels (China makes the most inexpensive solar panels), they would have
much more energy produced than the methane harvesting technology provides AND could use some of the Renewable Solar Panel harvested Electricity produced to
pump air down into the lake depths (through the same pipes they are now using to pump methane up) to prevent bacteria from anaerobically (i.e "living, active, occurring, or existing in the absence of free oxygen") metabolizing CO2 to produce methane (CH4). It being that CH4 is from 25 to 70 times more potent a GHG than CO2, preventing this methane from forming in the first place would make the floating massive solar panel project even more justified.
In addition to a
Renewable Energy bonanza, pumping air (which holds about 20.9% oxygen) down 300 metres (1,000 ft) would
dissipate anoxic conditions, thereby enabling lake fish habitats to expand.
If the air pumping is vigorous enough, the CO2 mixed with pressurized ambient air would cause the pH to go down towards neutral pH, another plus for fish viability.Over the long term, while providing plenty of energy for all the surrounding population, a
massive floating solar panel system, covering 40% or so of the surface of Lake Kivu, would prevent a future limnic event, improve the fishing economy, reduce surface evaporation, thereby providing more fresh water for agriculture and human consumption, and improve the surrounding environment in many other life promoting ways.
I mention surface evaporation because Lake Kivu, at 1,460 m (4,790 ft) above sea level, is a high elevation lake. All lakes at high elevations have high evaporation rates. Reducing the evaporation rate has many environmental benefits, though the lake temperature would have to be kept from rising too much as a result. According to Wikipedia,
the water temperature is 24 °C. For the sake of the lake fauna, you certainly do not want that, already rather high lake temperature, to go up.
Lake Kivu Methane extraction platform:
The methane harvesting plants can pe repurposed as oxygen and nitrogen pumping fish habitat enhancing plants. They could monitor lake evaporation rate, temperature, pH, dissolved oxygen, etc., and take appropriate action to prevent problems in any of those areas.
We have a GHG problem. We have a reduced fish stocks problem, not just in Lake Kivu, but in all the oceans and lakes of the world. Ironically (in addition to overfishing, of course), it's the low (acidic) pH in the oceans that threatens them, not the high (basic) pH as in Lake Kivo.
Lack of energy, clean water, adequate food and healthy cropland are human problems that must be addressed holistically. The methane harvesters only address the energy issue, while actually contributing to the other problems that guarantee Catastrophic Climate Change.
As the bird by wandering, as the swallow by flying, so the curse causeless shall not come. -- Proverbs 26:2
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