Wednesday, August 20, 2008

Laja trip

9:12am. Today we are going off to see a part of the Biobio River - the dams and upland areas... The temperature is quiteb low, and the river -as we head over the brigde is quite foggy. It is a very shallow river for how wide it is. I suppose that for much of the year it is quite low, but I also know there is a hydropeaking dam along its length, regulating the water flow daily from 10cms to 150cms, so knowing that it isn't surprising that it might not seem so full, even during what is normally a wetter part of the year.

10:44am. We just crossed the Biobio upstream and it still looks like a big river - for the area. Perhaps about as wide as the Grand River near Grand Rapids. Prior to that we crossed the Verigata River, which was being used as a water supply by the cmlp paper company's two factories - one for making presses paper (mainly for newspaper production) the other for making cellulose fiber for export (to make paper elsewhere). These two factories - and their biomass power plant - were much smaller than the paper mill we saw on our trip on Sunday to Chillan.

11:04am. We just entered the small city of Los Angeles. although I didn't get a cheesy photo of the city sign, I still managed to ge one of the power substation. The main road has a very nice park that runs between the two directions of traffic, and I would have taken pictures if the sun wasn't in my face (I did get one picture facing back along the road). Going along the road I saw something striking: a sign for Thames Water prominently displayed on a water tower. Since none of the local rivers are called 'Thames', I'm assuming that it's another example of globalization.

12:17pm. We are sitting in the conference/lecture room at the Rucue dam. The head engineer is describing the role of this run-of-river dam in the creation of energy in the Laja River (a tributary of the Biobio). They are able to control the river to a height of 140m head to produce about 180MW. There is a second loading chamber at Quilleco that can generate 70MW of power from the same water (if I understood it correctly). The energy is transmitted to the central substation in Charua (sp?) to the main grid. The energy production level is controlled at the dam. The energy is all generated by gravity, and is 140m and at Quilleco is 54m. There is a drop of 200m across 26000m, with a slope of 0.017 (check calc).

The head engineer is telling us how the entire system works. The water comes through the loading chamber and goes through the 'butterfly valve' - whic protects the Italian-made generator from the French-made turbine. (The plant chose this valve over the needle valve because the latter is better when there is a larger head. In addition, a larger head requires less flow, but since the head is not high, the butterfly valve is used. In Quilleco, the use a gate, not a valve.) It then passes through a 'snail' to generate a hydraulic force equal to that of the turbine. The water passing through the turbine turns the generator, producing energy. They take all the energy and transforms the 14,000V to 220,000V (50Hz) for transmission. As the water passes out of the turbine passes through a diffuser to minimize hdraulic disturbance in the river. The power house is divided into different levels - power generation, turbine, butterfly valve, and diffuser.

The head engineer is now going to give an overview of the company. Apparently, the colbun company was the first in Chile to offer carbon credits/offsets relating to the Kyoto Protocol. They are also involved with restoration projects in the upstream areas.

Even due to the diversion of the Laja River, a flow of 4.6cms is left in the river as a minimum ecological flow. If more than 120cms, it will be diverted to the spillway (not the river?). However, in the dry season, 4.6cms remains in the river. Immediately downstream from the diversion area, however, there is a lot of river recharge from groundwater.

Ari asked a question of the economics of distribution, and got a very interesting, and long, answer. The transmission of electricity in the central region is done by a third party company to whom distributors need to pay a tariff. Apparently the generation and distribution companies may be part of the same holding company (and there are many distributors and generators), but there is only one transmission company.

3:17pm. We just finished looking at both the diversion dam and the headworks of the dam itself. The first was in a large open area, and with all the rain we've been having these past few days, the reservoir was overflowing. The dam had nine passages, but only one was partially open. The rest of the water was either being diverted toward the dam or through a hand-constructed spill-way (a little was spilling over the reservoir dike). After returning to the dam area, the bus climbed a steep slope up just above the headworks. Needless to say, the view was great.

3:25pm. Inside thye power plant portion of the dam. It's quite loud from the turning of the generator. Standing on the metal plating, you can feel the thumming come up through the floor. It's so loujd that I can't hear the explanations without getting really close... But that's okay, because I'm not too interested in the specifics.

3:31pm. Going down to the generators. It is expected to be even louder.

3:41pm. Back on the top floor. Indeed, the generator room was very loud, and the pipes leading out of it were quite warm. Now we go into the control room. Lots of computers, and very quiet... The dam controllers also seem to have won a few soccer trophies. "Copa la Amistad" (2000, 2002 & 2006).

4:07pm. Outside, and the sun's warmed it up a bit. Out back of the dam were, of course, the 'siphons' making all the hydropower possible. After obligatory photos at the site, we're off to the Laja River falls.

5:41pm. On route 5, 'almost' at the falls. Actually, we just now got off the highway, and the sign for the falls is nearby. Getting odd the highway, we passed a dog running down the off-ramp. Don't want to know how that happened. The light nis turning that lovely shade of on-the-cusp-of-spring evening. Here we are now! Yay!

8:00pm. Back at the hotel. I'm going to bed now...

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