Once we got back from Kigali with all the materials (and Alison!) we made some final touches on the system at Kigogo and reopened it for business. I’ll explain some of the problems of the system and how we went about solving them.
The main civil works issues that Kigogo had when we arrived in Banda were as follows:
1. Water overflowed at several points along the channel in the rainy season, which caused hillside erosion
2. The site operator had no robust way to control flow into the system; his method of stoping flow to the settling tank was a combination of mud and leaves inserted into the channel
After brainstorming, weighing specification importance and comparing design alternatives like we’ve been taught at Thayer 🙂 we decided to construct a spillway just before the most severe point of rainy season overflow. The spillway was designed to let 12 L/s continue towards the settling tank while sending the remaining water back to the river. Downstream of the spillway, a sluice gate allows the site operator to fine tune the amount of water continuing to the settling tank and also stop the water completely when the system needs to be turned off.
The finished product seems to work pretty well. The real test will be during the rainy season though. We hope to get some pictures and reports of how it’s working in a few months. We did get great feedback from the community already though. When I was buying eggs, the shop owner told me, “God bless you, Kigogo is amazing.” June also got several handshakes and blessings at the opening of the Kigogo, when the site successfully charged all types of batteries faster than it ever had before. It is exciting to see the community respond positively to our work!
I realized as I was writing a post about civil works construction that it might be good to refresh the readers on the technical workings of our hydro systems. To briefly explain, we have two pico hydro sites in Banda, Rwanda and one in Rugote, Rwanda, each of which generate under 1kW of continuous electrical power to charge batteries. The power is generated by diverting some water from a steam on top of a hill and sending that water, at high velocity, through a turbine at the bottom of the hill. Here are some pictures and captions to help explain each component of the system in more detail:
I hope that this was educational! Please comment with any questions that you have!
While our concrete structures (which I’ll explain in the next post) were drying at the Kigogo site, Max and I traveled to Kigali with Pete, our Rwandan foreman, to buy several materials and pick up Alison from the airport. Up to that point, we had stuck to our aggressive project timeline, but after a few hours in Kigali we realized that staying on schedule was about to end.
We arrived on Wednesday afternoon and shopped for four hours. We found nothing that we needed and also discovered that Thursday was a national holiday, so everything would be closed. Perfect…so much for leaving on Friday…
Thursday we went to the Gikongiro Metal Market just to see if anyone was around on the holiday. The market is usually a pretty chaotic and exciting place. On the east side, you can find heaping piles of steel stock and welders doing work in only their sunglasses.
Separated by a gigantic pile of sawdust, the west side is home to several woodworkers creating surprisingly intricate parts. In the middle, rows and rows of tiny shops are crammed full of completely random and totally unorganized parts. And throughout the market, middle-men badger you, trying to earn a portion of profits, or at least get a tip for helping you find something.
Being the holiday though, the market was almost totally empty. We talked to a few middlemen and found out that the drainage pipes that we needed for our overflows don’t really exist in Rwanda or are very expensive. PVC pipes of the same size were actually less expensive. Again, wonderful… Bad news and still no purchases…at least we had time to play board games at our hostel. Max and I had been pulling pretty long hours in Banda, so a full night of sleep and day off wasn’t the worst thing in the world.
Our luck started to change on Friday though. I went to one part of town and found several small parts while Alison, Max and Pete went to the Metal Market and actually got great prices on PVC pipe by sending in Pete to shop around before revealing that he as with Max and Alison. The shop owners tend to hike up their prices considerably if they are selling to muzunguzs.
After a full day of shopping, we had almost everything and celebrated by going to the 4th of July party at the US Embassy. I’ve been out of the US for several months, so the stereotypical American 4th of July celebration was exactly what I wanted. It came complete with cornhole, a dunk tank, grilling, baseball and fireworks (on a projector screen hahaha).
After that, we went on a late night run to a westernized supermarket in attempt to find a plastic backing for our electrical systems. Options in the hardware stores were limited and very expensive, as plastic is a rarity in Rwanda (plastic bags are actually illegal). While I was looking through cutting boards and placemats, Alison and Max found our solution: bright green plastic tables. Check out the next posts, you’ll see them working out quite well.
Saturday was supposed to be easy. We just needed to have the supply truck pick up everything that we had ordered; we planned for it to leave for Banda by 2pm. As is often the case though, nothing was ready on time, people tried to charge us extra money, and after a headache of a day, the truck left at 7pm. It got to Banda at 2am and promptly broke down as it departed back to Kigali.
Back in Kigali, Max, Alison and I wanted more than anything to get down to Banda, but we had a few small errands to run on Sunday morning. I went to the Metal Market to attempt to buy expansion bolts without Pete to speak Kinyrwanda and negotiate prices (since he had gone to Banda in the truck). Since it was Sunday morning, the market was quite empty, so I reluctantly had to accept the help of a rather annoying english speaker who I knew would try to rip me off.
He brought me to a shop that sold the bolts I needed, spoke with the shop owner in Kinyrwanda and reported the price of 1000 RWF per bolt to me. But that wasn’t right… I thought out loud, “wait a second, the shop owner just said maganakane [400 RWF] for each bolt!” I had picked up just enough Kinyrwanda in Banda to understand their brief conversation and to realize that I was about to be ripped off. The man was stunned at first, and although I ended up costing him a profit of 600 RWF per bolt, he took it in stride and joked with me. As I was counting to make sure that they gave me all 50 blots, he blatantly said “You can trust us! We will try to charge you extra money, but we won’t lie to you!” And as I was leaving the market he said, “I can help you next time you come back. Now I know that you know Kinyrwanda. I will not try to expensive you!”
After picking up some materials to fix the broken down supply truck (sorry to the driver who was stuck in the rainforest that whole time!) we finally hit the road! We all couldn’t wait to get back to Banda after too many days in the big city.
Hey everyone, thanks for being patient in waiting for hydropower blog updates. Internet in Banda is obviously not the best, but I just completed my stay in Rwanda a week ago and am now traveling in Europe with some legitimate Internet. I’ll be putting up several new posts to get you all caught up, and I’ll be adding photos to previous posts. Be sure to check it all out.