It is all about the Vision

I can’t believe it is already the fourth week that we are in Tanzania. I hope everyone is having a great summer either working, studying (hi sophomore summer!), or relaxing! Last weekend, we kept ourselves quite busy.

Allow me to start from the beginning. On Saturday, we headed into Arusha town to do mzungu stuff. First thing in the morning, we met with Zainab or Mama Mpishi (the mama who cooks) to take a Tanzania cooking class. While she was going on with a list of the food we could make, we pretty much said that we wanted to cook everything. Zainab took us to a market near her home where we picked out ingredients for our meal, and the butcher’s shop to buy some meat. Then we went to her kitchen. She lives in a courtyard with four other families. A variety of activities including cooking, washing, playing, and socializing all happen in the small courtyard. The four of us proceeded to take out our notebooks and prepared to be good students.

Rachel, James, Tucker being good students and comparing notes.
Rachel, James, Tucker being good students and comparing notes (ie cheating)

The first item on the menu was chapati. It is a thin pan-fried pancake that is usually made on special occasions such as Christmas and Sundays. Basically, the main idea is that you make a dough with flour, water, oil, and salt, then layer more oil, and cook it on a frying pan. It reminds me of a very similar food my mom cooks. The steps are almost identical. It really amazes me that cooking is such a universal experience.

Emily attempting to make chapati
Emily attempting to make chapati

Last post, James talked about the meeting between us and EMORG. We were able to learn a lot more on Monday from visiting EMORG at Kisongo. Kisongo is a small village about 30 minutes from Arusha. A lot of children attending schools have no textbooks or a place to study after school. With a background in teaching, Didas started EMORG as a community library. Earlier this year, EMORG moved from a rented house to this new location that we visited. When we arrived, some teenagers were studying and discussing questions inside, while the carpenters worked on new tables and benches for the library.

Tucker and James being carpenters
Tucker and James being carpenters

We painted the wall two times in a white base paint, and once in another white paint. Afterwards, the building looked shiny with its new coat.  While we were laboring away at painting the wall, we also got a sense of Didas’ dream for EMORG. There was a half-finished building behind the library which Didas wanted to build into a vocational center with computers. Then, he wants to open up his own school for about 20-30 children, implementing an activity based teaching methodology.

The painting crew
The painting crew

Tuesday was a busy day for us with two meetings lined up. In the morning, the V4Y group came over to learn about our briquetting operation. Like we planned, we conducted a short survey asking the potential producers what they knew about briquetting and what their incomes were. Some members of the group knew more about briquetting than other members, so the survey quickly became a discussion amongst the group for sharing answers. Next time, we need to conduct individual surveys and explain that explicitly. Then, we introduced our four steps to a briquetting operation: biomass collection and drying, running a kiln, processing the mixture, and pressing. We involved all the participants in hands on demonstrations. Everyone had charcoal on them by the end. They seemed to really enjoy doing it. For us, this was the first time our group was actively involved in capacity building. It felt wonderful to have a group so eager to learn! We will be meeting with them on Friday to see their space for their business and go from there.

Rachel explaining how to pack a kiln
Rachel explaining how to pack a kiln
V4Y member pounding the charcoal
V4Y member pounding the charcoal
V4Y with their briquettes
V4Y with their briquettes

In the afternoon, we visited Sossy in Moivaro village, on the outskirt of Arusha city. Sossy is the pastor of the local church which he helped built. We met with a group of women who got together and started a briquetting operation last year which DHE helped with last summer. We were intent on finding out how the operation went. The women told us that it did not go well because the briquettes did not burn well. They felt like they spent a lot of time making the briquettes, yet what they made was not good enough to cook a meal without supplementing with charcoal. Most people in Moivaro could not afford to cook with charcoal regularly. Nowadays, even the firewood is hard to come by. The villagers either have to send their children into the forbidden forest with snakes to collect firewood or wait for outsiders to come by and sell firewood to them. The women abandoned their briquetting operation after the first unsuccessful attempt. They wanted to know if DHE was bringing in new technologies this time. We explained our process of turning biomass into charcoal and making charcoal briquettes. Sossy and the women did not seem to get how our new technology differs from the original technology. Needless to say, they were not too convinced. So the plan is we are going to make a lot of briquettes and bring the briquettes to Moivaro for them to try. If they like the new charcoal briquettes (which I think they will), only then will we be talking about a new round of capacity building. Later, Sossy invited us to his house for coffee. We learned about his vision for the people of Moivaro. I feel really inspired and humbled by people like Sossy and Didas who devote their entire career on helping people around them.

Wednesday night, we welcomed the arrival of our new housemates from the Netherlands who will be staying with us for the next five weeks. Mero, Gerrianne, Tim, and Dennis study at University College Utrecht. They will be interning at EARD-CI as part of a course on development. Specifically, Gerrianne and Tim will work on microfinance of the VICOBAs; Mero and Dennis will work on cultural tourism. They told us about their adventures travelling on a safari truck in the last four weeks in Tanzania and Kenya. I think we will have a lot of fun living together.  Between all this work, we have been running our kiln, making modifications on it, and pressing a lot of briquettes. We are going to turn into a briquette factory if we want to live up to the expectations of Sossy.

Until next time, bye!


Kiln to Briquettes

To begin where we left off, last weekend we busted out of Leganga and headed to Moshi for a change of scenery. On Saturday morning we caught a daladala on the Moshi-Nairobi Highway, and an hour and half later we were passing by the Coca-Cola sponsored clock tower on the north side of town. Every newspaper we saw was printed with Obama’s face in anticipation of his arrival on Monday. We spent the day walking around and exploring the streets, and stumbled upon a rice processing plant when we veered a bit off the major roads. They were drying out the grains before they were to be hulled:


Sunday we went on a walking tour around Mataruni, a village on the southern slopes of Kilimanjaro. We were able to connect with a young man named Richard who grew up there. He had recently converted a part of his family’s farm into area to bring guests (and tourists) to demonstrate how fresh coffee beans are prepared into a brew. He showed us how a large mortar and pestle is used to remove the husk from the beans before roasting. Quite a bit of work if you wanted to do it every morning. But in the end this trip was invaluable to our larger mission this summer, and the coffee was delicious.

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One of the major ventures of this past week has been the initial experiments of our freshly constructed tanuru (charcoal kiln). The charcoal from this kiln, made from sawdust, rice husk, and corn leaves given the season, will supply a clean burning filler for making briquettes. The kiln is designed to bring a large amount to biomass to a high temperature in the presence of limited oxygen. To perhaps make this a bit simpler, but also a little bit more inaccurate, let’s think of three different reactions:

1)      Gasification of Biomass: Biomass + Heat + Air (primary air) = Ash + Syngas + Heat

2)      Pyrolysis of Biomass: Biomass + Heat = Charcoal + Syngas + Heat

3)      Combustion of Syngas: Syngas + Heat + Air (secondary air) = CO2 + H20 + Heat

A bit funny to have heat on all sides of the equations, but the point to be made is that it takes heat to get started, but once going, the reactions can produce excess heat to run to completion. Syngas, essentially biomass that turned into gas, contains several compounds but has a high percentage of hydrogen gas so we can consider it combustible. Check out a picture of Rachel doing some work on our design:


The kiln is designed with four holes along the base which allow limited air to enter the packed biomass. This is where we begin 4 small fires to get the process going. The air will turn some of the feedstock into ash but it will also create a lot of heat which helps drives pyrolysis (reaction #2 above). So we let in a little bit of primary air into the kiln, sacrifice some of the biomass to ash, but create a lot of heat to make a bunch of charcoal. Because the top of the kiln is sealed shut, all the syngases produced get drawn into the chimney through an opening right below Rachel’s left hand. Rachel’s right hand is working on the secondary air tunnel which allows air to flow under the kiln and get preheated before entering the chimney. There the secondary air meets the syngas and a second round of combustion occurs. Most charcoal production systems in Tanzania simply allow syngas to escape, but our design will produce few emissions and create extra heat which can be fed back into the kiln.

Now we just need to figure out how to pack the kiln. Here’s a picture of the kiln filled with biomass (sawdust and rice husk). We are using some plastic pipes to make sure we can get primary air coming up from the base.


After removing the pipes, we have nice “biomass chimneys” that cut through the feed stock. Also nice to sprinkle some corn leaves on top.


Then take a piece of metal roofing properly cut to size and place it on top of the kiln. This will make sure that the syngas produced will enter the chimney.


Then cover the metal roof with dirt to make a tighter seal which also acts as insulation. Remember the kiln is gonna get hot! Then start some fires in the side holes (where the primary air enters). Here Tucker and Emily are inspecting one side while Naomi and Rachel work on the other. Most of the gas coming out of the chimney at this point was water vapor.


About 5 hours later we had dried out a bunch of wet sawdust and made a little bit of charcoal! We separated out our winnings, and I did a little physical processing to grind it up to dust. Thanks to Richard we had some experience with this before.


Then we mixed up some cassava flour (tapioca) and water, heated it up and made a starch binder which we then added to the charcoal mash. This acted as our briquetting mixture.


And from there we were able to start making briquettes in our new Musket Press. Exciting to see the whole process!

IMAG0435 IMAG0436

But we know we can get a better yield from the kiln, so we are setting ourselves up for success. We’ve taken all the feed stock we’re planning on carbonizing and are letting it dry out in the sun. Let’s hear it for surface area to volume ratio.


Another exciting update is that DHE has a new partner in Arusha, Vision for Youth, or V4Y, which offers health education and entrepreneurial training for young adults. Rachel and I first met with Violet, a cofounder of the organization, on Wednesday and heard that they’ve been wanting to start a charcoal briquetting operation for some time. All four of us went back to visit them again on Friday to meet with Veda, the other cofounder, and Happy, Raymond, and Pendo, some of the “youths” (they’re our age…) who are interested in briquetting. A wonderful meeting that left everyone energized! They’ll be coming out to Leganga on Tuesday to see our developing briquetting operation.

Next week will be a busy one. After meeting with Didas and Maricel from EMORG (Educational Model Organization), a growing library/vocational/community center, we promised to help them paint their new building on Monday. On Tuesday morning we have the V4Y group visiting, and then we are going to go meet Julius Sossy and the briquetting group he helped DHE begin last summer in his village of Moivaro. Then on Wednesday we will be visiting Bernard, an inventor who runs an organization to inspire young Tanzanians to solve their own technical challenges who has also helped us design stoves in the past. We want to talk to him a bit kilns and briquettes. I’m sure he’ll have a lot to say. And in between all of those visits and meetings, we’ll keep making charcoal, keep making briquettes, and keep making food. More updates soon, Kwa heri!

Civils: Solutions for Erosion

Alison landed in Kigali on Wednesday, and Joey, Max, and Pete, our foreman, left Banda at 4:30AM that morning to go pick her up and go on a materials run. Mountains surround Banda on all sides, and accessing the main road involves a two hour, steep uphill hike up the side of one of the mountains. They were hoping to catch the 7AM bus to get to Kigali by around noon.

In the week or so leading up to their departure, we started modifying our site at Kigogo. Rwanda has a rainy season, which falls roughly during our winter, and we have to make civil modifications to both of the sites so that they can fare better against the increased water flow during this period. One of these changes involves increasing the number of overflow channels in the system. When there is more rain than our system was designed for, our channels overflow, and water gushes down the hillside that our channel runs along. The water erodes the soil from the hillside, causing a mini-landslide from our channel, down to the kiosk.

Overflow channels create an alternate escape for the excess water. By lowering the height of a short length of channel wall, whatever water is above that level flows into an alternate path. At the erosion points, we lay cement so that the water is funneled into a PVC pipe. PVC pipe then carries the excess water down the hill and returns it to the river. The water originally came from upstream the same river.

An example of an overflow. This overflow is at the intake at Nyiragasigo where we divert some of the water from the river into our hydro set up. Behind the channel wall is just a continuation of the original river. When water passes through that overflow, instead of going downhill or through a PVC pipe, water directly returns to the original river. This intake overflow limits the amount of water that originally enters the system. This overflow was made by the 2008 trip when they originally implemented the system.

Looking downhill from the channel at Kigogo, we can see the river, the kiosk that houses the turbine and the electrical set up, and the hill that we will be placing the PVC pipe for the overflow in. The PVC pipe returns the water from the river to the river that it originally came from.

Another issue we’ve been looking at is the stagnation in certain parts of the channel. We’ve noticed that there’s a build-up of silt in certain parts of the channel, and although this isn’t entirely negative as it means that silt is settling out of the water before the water goes through the turbine, it also means that water may not be travelling through the channel quickly enough. To fix this, we will be increasing the slope of the channel at certain points, such as the channel right by settling tank at Kigogo.

Increasing the slope of the channel could also help decrease erosion. At Niragasigo, the slope of the channel at two of the erosion sites is close to zero. By increasing the slope here, we increase the speed of water flow through the channel. When there is excess water entering the system, having a higher slope moves water down the channel more quickly and minimizes overflow.

A temporary solution to soil erosion is to lay soil bags by the channel. This increases the height of the channel wall and also prevents contact between the water and the hillside’s soil. This is not an ideal or permanent solution to the erosion, but it is cost-effective and very easy for local workers to replace in our absence.

At Kigogo, we’ve already laid the cement for the new overflow by the settling tank and changed the slope of that segment of channel. We’ve also laid our soil bags. Right now, we’re waiting for the cement at Kigogo to dry and for Joey and Max to return with PVC pipe for the overflow.

They’ll also be returning with metal to build a sluice gate. Typical hydro set ups use a rotating gate valve as a sluice gate, but to maximize the ease of repair, we’re planning to build our sluice gate using only a metal panel, secured by L-profiles. The sluice gate stops water flow into the system so that the system can be dried out for maintenance.

We’ll also be able to finally implement our electrical system in its entirety. The plastic box that we’ll be mounting our electrical set up in will be arriving, as well as additional circuit breakers for the Nyiragasigo system.

While we’ve been waiting, Sophie, June, and I have worked on making updates to the Impact Analysis survey, learning more about the electrical system, and taking measurements at Nyiragasigo in order to inform civils design.

Joey, Max, Alison, and Pete are planning to come back tomorrow afternoon. We’re excited to get back to work at Kigogo!



DSCN7990The nights in Banda are quiet and dark. On the deep blue backdrop of the sky, lamp lights from the distant hills blink like stars. Batteries, charged by our hydropower sites, power these lamps.

During the past week, our electrical team has tested and examined the current electrical systems at both Nyiragasigo and Kigogo sites. We obtained useful information in terms of the following three aspects of the system. The first aspect is the design, layout, and subsequent modifications of the electrical set up. The second aspect is the knowledge and usage habits of the site operators. Observations of human interactions with the system help guide our future design. The third is the kiosk architecture, which determines how the space can be used.

As expected, the current electrical system has a number of problems. Some of these issues were due to the original DHE design, while others resulted from modifications to the system by local technicians. The site operators have not noticed any issues with the current system, as it works well for normal operation. Our updates aim to protect the system against the most extreme of fault scenarios.

Firstly, the wires in the current system are too skinny. If high current levels pass through the wires, they can potentially heat up as current passes through them and dissipate valuable energy as heat. The thicker wires that we are using in the new system will dissipate less heat and waste less energy. This modification raises the overall efficiency of the system.

Moreover, all of the circuit breakers that were implemented in previous trips have mysterious disappeared from the Nyiragasigo system, and the Kigogo system has been left with only two 40A breakers. Circuit breakers turn off and break the circuit when they detect that a current above their rating tries to pass through them. The absence of circuit breakers is dangerous because circuit breakers protect wires, expensive equipment, and people from large currents. Missing circuit breakers mean missing safeguards against accidents.

In addition, some of the current connections have been made using either two touching wires, held together by the electrical tape wrapped around it or by exposed terminals that could be shorted.

Other issues with the current system are the absence of a permanent storage battery and the disconnection of dump load resistors from the system. The permanent storage battery prevents the voltage from fluctuating by absorbing and releasing extra charge when necessary. Dump load resistors dissipate extra energy from the system when the batteries have been fully charged. Without these two, the system loses its ability to regulate voltage. As a result, the current system has a much higher probability of experiencing uncontrollable voltage spikes.

The storage batteries were sold to users as personal batteries to profit the site. I asked the site operator why the dump load resisters were disconnected. He said that the dump loads were heating up during battery charging and “taking power away” from the batteries. They believed that without the dump load, batteries would be charged more quickly and fully. However, charging batteries is analogous to feeding hungry people. When someone is already full, the extra food that they can no longer consume has to be “dumped” somewhere. If the extra food is not dumped but is fed to the person instead, the man will suffer. Overcharging batteries is unhealthy for the batteries and can shorten their lifespan.

Another issue is how disconnected battery connectors and clamps are used in the system. When removing a fully charged battery, the site operator takes off both clamps to the battery and reclamps the positive end to a plastic box while allowing the negative clamp to dangle freely in the air. This is dangerous, as any contact between any of the system’s positive and negative clamps will short the system and induce a large current through the system.

The 13X electrical team has put many careful considerations into the system. We used sturdy screw-in wire connectors, thick wires, and enclosed intersystem bonding terminals to minimize possible tampering of the circuit. We also design shelves with insulated storage places for battery clamps. Sophie, Shinri, and I have worked to take into consideration the site operators’ habits.


We have already assembled the electrical systems for both of our sites and are waiting on the completion of the civil modifications to the two sites before implementing our updated electrical systems. Testing of our new system has been going well. Yesterday, we spent five hours at Nyiragasigo taking current and voltage measurements for all of our components and have already proved that the new system has a higher power output than the one we will be replacing.

Every day, when we walk out of the kiosks at our two sites, we are greeted by layers beyond layers of different shades of green. We see the banana trees line the path to Nyiragasigo and the butterflies that flock by the stream next to the Kigogo kiosk. Banda village and its kiosks are already a part of us, and we hope that our efforts will help the hydro systems be the best that they can.

Cooking & Kinyarwanda

Pascal cooking

Dinner every day is close to a four-hour affair. Tonight, Sophie and I started cooking the rice a little past six while June was out visiting Kigogo with Pete. Joey and Max, meanwhile, worked on calculations for civils designs. “Civils” refers to the larger, structural parts of the system, like the channel that brings water to the turbine. Joey and Max eventually left for the market and bought around 1500RWF in groceries, roughly three dollars US. This is enough to feed the eight of us for the night.

Cooking with the open wood-burning stove has made us think of the bioenergy team and their previous initiative for clean cook stoves. The stoves that we cook with spew smoke, and although we open the windows and the door, it’s uncomfortable to be in front of the fire for a long time. The smoke bothers me, and I often have to step out of the room for a breath, but I notice that our Rwandan counterparts are unfazed.

Pascal is a student from the Kigali Institute of Technology that has been working on the sites with us, and he seems completely unfazed by the smoke. Jeremiah, a long-time DHE contact in Banda and a doctor in the village health clinic, and Pete, our foreman, can indefinitely continue to stoke the fire and peel potatoes in the small kitchen.

For the people cooking with it every day, the smoke can be lethal. Over the years, the air pollution takes a serious toll on their health. Because they’re not bothered by the smoke, there’s also little incentive to look for alternatives. Jeremiah’s petroleum-fueled stove sits next to the wood stove, but he leaves is unused. As a doctor, he has one of the highest incomes in the villages and is the most conscious about his own health, but still, the price of petroleum is too high.

Once we finished cooking, it was past 8:30 and we wolfed down the food. Two nights ago, we talked with Pascal, Jeremiah, and Pete about marriage and relationships in Rwanda, the overturn on gay marriage in the US, and the expansion of the universe. It was a great night. Tonight, as we finished our dinner, Pete announced that we’d be learning more Kinyarwanda. We pulled out our notebooks and turned on our head lamps.

How do you call this?: Ichi cyitwa gute?
I want: Dashaaka
I like: Ngunda

Egg: Umagi
Potato: Ibirayi
Sweet Potato: Ibijumbo
Bread: Umugati
Onion: Ibitunguru
Tomato: Einyanua
Rice: Umucheri
Salt: Umuunyu
Pineapple: Inanasi

One: Rimwe
Two: Kabiri
Three: Gatatu
Four: Kane
Five: Gatanu
Six: Gatandatu
Seven: Karindwi
Eight: Umunaani
Nine: Icyenda
Ten: Icumi

Spoon: Fork
Fork: Ikanya/Ifork
Knife: Icyuma

Other words that we already knew:
White person: Muzungu
Yes: Yego
No: Oya
Good morning: Mwaramutse
Good afternoon: Mwiriwe
How are you?: Amakuru?
I’m good: Ni meza.

I didn’t get to write down all of the words that we were taught, but hopefully I’ll get to learn more as the weeks go on. We finished at around ten, and the six of us from Dartmouth talked for a few hours, updating each other on our progress for the day and talking through some of the more controversial design decisions. Our days are long but rewarding.

Alison, our last traveller, gets here at the end of the week. We’re excited to see you!