Calvin Helfenstine, a recent graduate from the University of Michigan in Mechanical Engineering, was an Intern with AsoFenix in Nicaragua in 2008 through the Engineers for a Sustainable World’s Summer Engineering Experience in Development (SEED) program. Calvin built on the work of SEED Intern, Samuel Schlesinger, who contributed an earlier blog posting.
SOLAR WATER PUMPING STATION
The solar water pumping station in Sonzapote was the most important and largest budgeted project from the position of Asofenix. Initially, a topographical study was performed to determine the elevation of various elements of the community. Working with Nicaraguan surveyors, we spent a day in the village collecting data. Upon review of the topographic study, we were able to accurately size the pump and solar panel system for the community’s needs. A community census and survey was also conducted to accurately determine the water usage needs of the village throughout the year, and attempt to document the state of the village to determine what changes occur with this project. While administering this survey, we explained the necessity of having a latrine before receiving water to the house. In addition we documented the level of education of each community member. The results showed that less than half of the community was able to read. With the winter harvest underway, we were unable to begin installation of the system before the end of our program. The equipment was ordered and the project is scheduled to be completed by the end of November of this year. [*ed note – the community water delivery system was installed in December 2008 and the distribution network was completed by the community and AsoFenix in Feb. 2009.]
MICRO WIND GENERATOR
Collaborating with students from the Universidad Nacional de Ingenieria (UNI), we worked on a project to construct a wind generator made of recycled materials to be used for charging batteries in the village of Bromadero. Based on a variety of existing generator designs found via the internet and a site visit to an existing wind turbine in Matagalpa, an overall design was developed.
One week was spent with the students at the UNI workshop to fabricate the design. Although well equipped for working with metal, there were insufficient resources to fabricate the wooden blades. Having trouble locating the necessary materials, we were only able to fabricate a tail and make preliminary cuts for the blades. The project was put on hold until we could locate a new location with proper machines for woodworking.
When we convened on the project, we again encountered more problems. Without prior notice, the school had closed for a week and all the previous supplies were locked in the workshop. With limited time to complete the project, we decided to take on a new design using blades made of PVC tubing. The design would allow us to complete most of the work in the office of Asofenix with minimal equipment required.
The blade design was modified from existing designs on the internet using 6 inch diameter tubing with a blade length of three feet. The tubing was cut to length and quartered lengthwise. A small taper was cut into the blade to serve as the leading edge. Once cut, the blades were sanded to form rounded corners and leading and trailing edges. The components of the design were made of recycled and cheap materials. A used saw blade was purchased to serve as the central hub to mount the blades to the generator. The tail was fabricated from sheet metal and scrap tubing purchased from a junkyard. The wood for the main body was donated from a local construction site. A motor was purchased from the Mercado Oriental, Central America’s largest market, with the help of “runners” and a fellow Nicaraguan Asofenix worker. We were unable to successfully describe the type of motor needed and the motor purchased was unsuitable for use as a generator.
Further research showed that the types of motors best suited for wind generators (permanent magnet DC motors) could be easily found used in the U.S. from items such as old tape drives, treadmills, or washing machines. None of these items, however, are prevalent in Nicaragua. In addition, due to the culture of re-use until broken, it is difficult to locate a used motor for sale that is still serviceable.
We met with a professor of wind energy at another UNI campus who had tried to make wind generators for years without success. Many student-made models were scattered around his trailer-based office but the only wind generator in service was a purchased unit from the U.S., which was spinning above his office. Reassured that it was indeed difficult to produce such wind generators in a country with the necessary resources, we decided to find a suitable motor to serve as a proof-of-concept. A 12-volt fan from a bus was located and used for preliminary testing.
The “testing” involved holding the assembled unit above our heads in the back of a pickup truck while driving down the road. The voltage was read with a multimeter while driving at speeds up to 25 miles per hour. With the small motor we were only able to achieve just over one volt but the blades did prove to spin rapidly and serve well. When a proper motor can be located (it will possibly be imported with a future volunteer) the design can be implemented to serve to charge batteries as desired.
We also installed a biodigestor in Candelaria to provide biogas for cooking for one household. The current cooking practices involve carrying large limbs miles to the home and cutting them into smaller pieces to be used as firewood. This system results in additional physical labor, deforestation, and indoor air pollution.
With a biogas digester, animal manure is processed through anaerobic digestion by bacteria into biogas composed of 70% methane. This gas is then piped into the home for use with a gas stove. The waste matter from the system is a sterile liquid, which can be used as an organic fertilizer. The particular design we used is called the “salchicha,” or sausage, in Central America as it involves a large sausage-like plastic bag open on both ends.
Working with the family, we first laid out the footprint for the biodigester basin. We then excavated the hole and shaped the walls as desired. A reservoir was created to serve as the entrance for the slurry as well as an exit reservoir to contain the fertilizer. The walls were then lined with rocks and cement to form a barrier with the soil.
The plastic bag measured 4 meters long with a width of 2.5 meters (doubled over). A small hole was cut in the top of the bag to serve as the outlet for the biogas. A hollow plastic male fitting on the outside of the bag was screwed into a female connection on the inside with a set of washers and rubber squares between to serve as a sandwich connection to the bag. The bag was connected to the inlet and outlet tubes, which were four inch diameter PVC tubing. Semi-truck inner tubes were cut into strips and wrapped around the bag, which was pleated to fit snugly around the tubing. The completed setup was placed in the hole and outlet tube covered with dirt.
Before leaving the village upon completion, instructions were given to fill the bag with manure and water with a ratio of two to one. Approximately two cubic meters of slurry were needed to fill the bag. Upon returning to the village we discovered that one of the valves had been left open and all gas that had been produced had escaped the chamber leaving a deflated bag. Upon reassuring the villagers that the design did work, they continued to fill the bag daily. Although we did see much activity such as bubbles seeping through the mixture, the bag did not fill in my two days that I had left in the village. The design takes approximately one week to produce enough gas to fill the bag but provides enough gas to cook daily once it is operating.
My experience was some of the most interesting and personally gratifying time I have ever spent. During my eleven weeks in Nicaragua, I got a glimpse of what it is like to live in a third-world country, a life that closely resembles most of the world. Although the lives of the people of Nicaragua may not be glamorous by U.S. standards, I believe they live a satisfying life on a personal level. The pace of life is less stressful, family ties are stronger, and the people are generally grateful for what they do have.
During my first three or so visits to the village I did experience a bit of culture shock. Each time I went back to the village, I would be more used to the lifestyle but new things would keep coming up that were extremely different than the life we are used to. With time however, bucket showers, latrines, animals in the house, wood-fire kitchens, and beds made of plastic fabric seemed normal and somewhat comforting with each visit.
My Spanish skills were poor at best when I arrived in Nicaragua. Over my time in the country I was forced to improve my skills just to communicate with my host family. Although somewhat frustrating at times, like a game of charades, my Spanish skills developed extremely. Although not always perfect, I was able to successfully participate in meetings, conduct surveys, and work alongside native Nicaraguans with little or no problems communicating whatever desired. As these skills developed, I was also able to form a relationship with my host-family and fellow workers.
I developed a strong understanding of the Nicaraguan way of life, values, and culture. I became deeply immersed in their lifestyle, sometimes shedding my American idea of things. At one point, a fellow volunteer and I refused to rent bicycles for U.S. $2.50 because they were charging us too much. In hindsight, $2.50 is nothing with U.S. spending habits, but for the lifestyle we were used to it seemed ridiculous. When we did happen to see tourists from other parts of the world, they seemed to stick out much more than us.
Seeing the excitement of the villagers with our projects was very encouraging and rewarding. During our survey of Sunzapote we discovered that only women and girls carried the water to the homes by buckets weighing forty pounds. When asked why they wanted this project in their village, we got a variety of responses but nearly all were with a smile. Women were excited to be able to spend more time with the children, taking care of the house, or taking a minute to relax from their hard-working days. I am positive that this project will improve the lives of everyone in the village and is one large step towards improving their living conditions.