Hydroelectric is a source of greenhouse gases?

Hydroelectric is a source of greenhouse gases? (See here) an article in the New Scientist that claims this is so. Gee, I guess this global warming problem might be more complicated that I had imagined.

I am grateful that "the experts" are at least thinking about stuff like this. However I do not completely agree with the conclusion the author, Duncan Graham-Rowe leads us to. While I accept that some initial greenhouse gas emissions will occur as fields and forests are flooded I do not accept that continuing emissions must occur as the reservoirs are drawn down and then, later, the water level rises again (he points out this is a bigger problem in tropical locales then cooler locations).

I still think hydroelectric is going to be a sizable part of the solution. If varying water levels is a "problem", then solve the problem but do not abandon hydroelectric. Seems to me that we could find some type of material to coat the "drawdown region" with to prevent new plant life from growing. A thin layer of concrete would serve, although maybe someone could come up with a cheaper and more practical material that would serve better.

"Experts" like this author are the kind that frustrate me. If someone without an education in the field can come up with a solution to the "problem" they present, what are experts like this doing calling themselves experts? We need "experts" that can come up with solutions to the problems not just point out to us we have problems while motivating us to just throw up our hands and give up.


Blogger Little David said...

Hey, here's an idea that might be better then concrete. How about biodegradable plastic sheeting? I dismissed "ordinary" plastic sheeting because it has some big drawbacks. But I think I remember hearing of biodegradable plastics. It costs more then ordinary plastic, but in the long run it probably would be easier and cheaper then concrete.

12/20/2005 10:54:00 AM  
Blogger Michael said...

The problem with hydroelectricity (or dam building in general) is that it is often set up in places that can't really support it (e.g., places that don't actually have a great surplus of precipitation).

So yes, down stream ecology is often significantly affected. Upstream "drowning" of trees can release a significant amount of carbon... not to mention that often building the damn thing is incredibly energy intensive.

There is no such thing as a free lunch and not calculating the full environmental/ecological cost can often given deceptive results (e.g., the energy estimates in building a nuclear power plant as well as in its decommission is often not factored into calculations of its "energy efficiency").

Michael Tam

12/21/2005 07:57:00 AM  
Blogger Little David said...

Well, that is treading dangerously close to the Dubyah administrations argument against dams. Christie Todd Whitman, Dubah's former head of the EPA argued against dams because "what do you do if there is a drought" for areas that CAN support hydroelectric dams.

As for the problem of flooded trees, just go in and harvest the trees ahead of time. The author made the point that flooding trees results in not just CO2 but methane who's effects are 21 times stronger on global warming then CO2. So just harvest the trees ahead of time instead of flooding them. We still need to get lumber from somewhere.

Downstream ecology might be greatly affected, but global ecology is going to be affected by global warming. We have to come up with our energy needs from somewhere and I think using hydroelectric in places that can support it is a wise decision.

Hydroelectric is not perfect because there is still the problem of silting in the reservoirs. But perhaps that problem is far enough into the future that we will have perfected fusion by the time we have to deal with it.

12/21/2005 09:44:00 AM  
Blogger Michael said...

Unfortunately, "harvesting" trees (the majority of which would probably be unsuitable for industry) would probably make an economical dam project rather uneconomical. It is much easier for the bean counters to assume there simply isn't a problem and let the greenhouse gases invisibly leak away.

Michael Tam

12/22/2005 09:02:00 AM  
Blogger Little David said...

You might be surprised what uses for trees industry has. For example, if a tree is unsuitable for lumber it can be ground up for paper. Presently they even grind up "perfectly good" trees that could be used for lumber. Momma has got to have her paper towels after all.

The only thing that might make it uneconomical to harvest the trees would be if the location was remote without access to roads. So you just build a road? Access is going to be needed for maintenance of the dam anyway.

12/23/2005 05:08:00 AM  

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