'Exploding Lake' Provides Electricity For Rwanda

reillymj writes "There are three known 'exploding lakes' in the world, where volcanic gases build up near the lake bottom until they suddenly fizz over, suffocating people with huge amounts of carbon dioxide. But the lakes also hold methane and one of them, Rwanda's Lake Kivu, is being actively tapped as a source of natural gas to fuel a power plant on the lake's shore. The government hopes that within two years, the plant will be covering a third of the country's needs. By siphoning off the gas, engineers simultaneously defuse a ticking time bomb in the lake and provide power to local communities."

Comments

This is the stuff

[Some.Net(Guy)]

This is why we have science. Good stuff all around, assuming it doesn't get corrupted.

Re:This is the stuff

[Anonymous Coward]

I am a chemical engineer from South Africa. We studied this project back in the early 90's, when I worked for the South African national oil and gas exploration company. Economically, it is a no-brainer, as the gas is trivially cheap to exploit. But some corruption, and some genocide, got in the way and so now it has taken 20 years. BTW, the local bottling company wanted the CO2.

Re:This is the stuff

[Cytotoxic]

The takehome for me was the amazing measure of just how small the Rwandan economy is - a single smallish power plant can supply a third of the country's power needs. That's a pretty good measure of how "third" the third world can be. The tiny town of Lake Worth Florida is considering adding 90 MW of capacity to their city run utility's power plant. Compare that with the planned 50MW capacity for the Rwanda plant. Simple math tells me that they plan for 150MW to cover the entire country in two years. Compared with one small town in Florida. And calling Lake Worth a town is generous. It is only a couple of miles long and wide - really more of a suburb of West Palm Beach. Which is sad in its own right - a suburb of a suburb of somebody's second home. (West Palm Beach services Palm Beach, where all of the rich folks have their second or third homes).

Good idea

[VonSkippy]

Here in the State's they do the same thing with Taco Bell toilets.

Re:Good idea

[Penguinisto]

You're close - in the States, we actually generate power off of the Taco Bell grease traps...

Re:Good idea

[hedwards]

We also do it with landfill off gassing. It takes a fairly sizable landfill, but the gas is going into the atmosphere anyways, may as well trap it and burn it.

Could use the CO2 to generate electricity, too

[sznupi]

When the water is brought up in a pipe to syphon out the dissolved CO2, you only need a small initial "push" - afterwards the bubbling of gas forces the flow / gives you a fountain. Why waste it? Seems like an ideal opportunity for small, simple turbine solutions...

Re:excuse me...

[xMilkmanDanx]

... but won't burning methane for energy contribute to global warming?

Negative. It would be released anyway and methane is a worse greenhouse gas than the CO2 from burning it.

Re:excuse me...

[sznupi]

It would be released at some point anyway (methane and also dissolved CO2), but in a much less controllable, much less pleasant way (lake Kivu is mentioned). By siphoning it out gradually, you can not only deal with the danger, but also get some useful energy as a bonus.

Also, methane is a much more potent greenhouse gas than CO2, so burning it prior to release actually lessens overall impact.

From the second article:

[MRe_nl]

quote 1;
The world's only two other known "exploding lakes", Monoun and Nyos, both in Cameroon, overturned in the 1980s. The clouds of carbon dioxide that burst through from the deep water left about 1,800 people dead from asphyxiation. But Lake Kivu is nearly 2,000 times larger than Lake Nyos, and is in a far more densely populated area. Cindy Ebinger, a professor of earth sciences at the University of Rochester in the US, who co-authored a study earlier this year that described Kivu as possibly "one of the most dangerous lakes in the world", said: "You don't even want to think about the scale of the devastation that could occur."
quote 2;
To harvest the methane, heavy water is sucked up through a pipe to the barge, where the liquid and gases are separated. The gas then enters a "scrubber" that separates the methane and carbon dioxide. Ebinger said reducing the overall concentration of gas in the water was a positive move, but warned that more studies were urgently needed to assess the potential environmental impact, especially relating to the unused water and carbon dioxide pumped back into Lake Kivu from the barges.
quote 3;
"With so many projects, if you don't understand everything, you can solve one problem and create three more," she said.
quote 4;
Regardless, Rwanda is proceeding at great speed".

Erm, is it just me or is there a lengthy "whatcouldpossiblygowrong" in there, Mrs. Ebinger?

Re:From the second article:

[maxwells_deamon]

The problem here is that is will blow at some time in the future without help. It may be triggered by a volcano or some other random event. It will eventually go off all by itself.

If you ignore it the potential just gets larger.

Such a poor country...

[mangu]

What struck me in TFA was the scale of the project. 3.6 MW will provide 4% of the whole country's electricity needs.

To put it into perspective, the largest power plant in the world, Itaipu dam, has a 14000 MW capacity.

How does that city exist?

[Posting=!Working]

3BR, 2BA brick house in great neighborhood, large porches and patios, 1 acre fenced yard with pool, conveniently located near schools, bus lines, restaurants, lake that occasionally explodes and kills everyone, city parks. New carpet! $175,000.