2007 Progress Report: Solar Photovoltaic and Wastewater Treatment Systems Design for Communities in PanamáEPA Grant Number: SU833758
Title: Solar Photovoltaic and Wastewater Treatment Systems Design for Communities in Panamá
Investigators: Snurr, Randy , Barbosa, Christina , Nigorizawa, Kari , Rogacki, Kevin , Summersgill, Bethany , Vega, Christopher , Yu, Suelyn , Zhang, Richard Zheng
Current Investigators: Snurr, Randy , of Engineers for a Sustainable World, Northwestern Chapter
Institution: Northwestern University
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: June 1, 2007 through May 31, 2009
Project Period Covered by this Report: June 1, 2007 through May 31,2008
Project Amount: $74,093
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2007) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Energy , P3 Awards , Sustainability
Northwestern University’s Engineers for a Sustainable World (ESW-NU) chapter has been involved in locally sustainable projects in Panamá since the spring of 2005. During the first trip to Panamá, ESW-NU identified the need for solar-powered electricity in the Chagres National Park and for improved wastewater treatment in the town of Portobelo. These issues were addressed by two teams of students, and were solved in economically and environmentally sustainable methods. The projects are still ongoing, but much has been accomplished toward improving the quality of life and the community sanitation in the two areas of Panamá.
Solar-Generated Electricity Projects
The student team working with solar-generated electricity has been collaborating with communities in the Chagres River Basin, a national rainforest in central Panama. Because of the land’s protected status, most of the park’s villages are cut off from modern conveniences such as paved roads, access to medical care, certain resources for elementary education, easy access to higher education, and access to electricity. The park’s communities have an immediate need for reliable electricity generated in a way that fits within national park guidelines. Children and adults require a place to study, read, and meet during the evenings. The various solar projects seek to fulfill those needs while incorporating education with implementation by designing and implementing sustainable solar-generated electrical systems (e.g. photovoltaic systems) and educating the community about how to build and maintain the systems. Secondary objectives include expanding educational opportunities for the national park’s children, giving Northwestern students a chance to apply their engineering skills outside of the classroom, and educating Chagres communities on proper electrical safety. Implementation includes design, purchase, installation, and solar education for these communities.
With funding from the P3 Phase I grant, ESW-NU completed two projects in the Chagres community of Santo Domingo. The first was solar-generated electricity to power community buildings. The second was a hydraulic pump system to pump water to water troughs on higher ground in order to prevent erosion and sediment buildup at various cattle watering holes.
The objectives for Phase II of ESW-NU’s work in Panama were to continue to monitor the installed systems in Santo Domingo as well as implement similar systems in other communities within the national park. A modification to the system design for the community of Santa Librada was to include a freezer system in addition to the lighting system at the school and church because the community is extremely spread-out and children eat regularly at school. Further developments in Santo Domingo included a computer to improve the quality of education and the beginning of individual house electrification, which promotes efficiency in the home and an extension of available work hours.
Wastewater Treatment Project
The wastewater project is focused on restoring and updating a community septic tank serving approximately thirty houses in the Guinea neighborhood of the town of Portobelo. The septic tank empties into a creek which runs through the middle of the town, along a historical fort, and empties into the Portobelo bay. At the beginning of the project, the septic tank was full of solids because it had not been emptied in over forty years, and the piping was corroded and partially clogged. In this state, the septic tank is essentially incapable of treating wastewater before releasing it into the creek, resulting in raw sewage pollution which is detrimental to public health, aesthetics, and tourism. The primary objective of the wastewater project is to improve the water quality exiting the septic tank in a sustainable method. This will be accomplished by restoring the existing community septic tank to working order and by adding filtration components to the waste treatment system. Secondary objectives that will occur as a result of this work are improved health of citizens, increased community awareness of health and sanitation, and enhanced aesthetics of the creeks, which promote tourism. These will be accomplished by involving the community in the planning, construction, and maintenance of the proposed wastewater treatment system and by giving educational courses on health and sanitation in schools throughout the community.
Solar-Generated Electricity Projects
ESW-NU students and advisors have traveled to Chagres National Park twice since Phase II began, implementing new solar-powered systems and modifying existing ones based on community needs expressed in previous trips. Students spoke with community members to learn about their needs and began work on three projects. First, Santo Domingo’s teacher and parents addressed concern that their children were not prepared for high school education since there are no computers within the village. Thus ESW-NU worked to integrate a computer within the school’s electrical system. Second, Santo Domingo’s families were having difficulty utilizing the school’s charging station since they had to carry their 50 lb. batteries through steep, muddy terrain between their houses and the school to charge them. So ESW-NU began planning the electrification of individual houses to eliminate this step. Third, the nearby community of Santa Librada contacted ESW-NU with requests to help solve problems related to the spread-out structure of the community. ESW-NU students designed lighting systems and a refrigerator/freezer system for the school and church, which provide a gathering place for the community and provide food regularly to schoolchildren and visitors.
In December 2007, a trip team traveled to Santo Domingo to check on existing electrical systems, install a laptop at the school, and survey residents about electrifying their homes. The existing systems at the school, church, and ranches were in good working order, and only one charge controller had to be replaced on a solar-powered electrical fence system at a ranch. Next, the trip team and the community’s solar committee added a laptop to the existing school electrical system, which was originally configured to charge batteries and power lights. With community members and children observing, the trip team taught the solar committee how to operate the laptop’s Spanish Windows XP operating system and educational programs. Finally, the trip team traveled to individual households and surveyed them, successfully documenting the layout of homes and residents’ power needs. During this trip, the team also visited Santa Librada to install its first two electrical systems: one AC (alternating current) system to light the adjacent school and church, and one DC (direct current) system to power a new refrigerator/freezer. Both systems were installed successfully.
During the winter of 2008, these survey results were used by a student team at Northwestern University which designed a simple photovoltaic system for individual houses. They developed an average household power need (a DC TV, two lights, a radio) and used these figures to calculate the best combination of components for the houses of Santo Domingo. The final system was DC and consisted of a 60 W solar panel, 45 Ah battery, and a Morningstar SHS-6 charge controller. During the spring of 2008, ESW-NU students worked to find and create educational materials to help community members learn how to install and maintain the systems.
In August 2008, a trip team visited Santo Domingo to begin installing the individual house electrical systems. ESW-NU’s worked side-by-side with the Santo Domingo solar committee to install the first two systems. The solar committee proved so adept at installing the systems properly that they were able to install a third system without any help. The trip team found that the school’s new computer had been a success as well. The school teacher reported using the laptop in his teaching about twice a month. The trip team added several more user-friendly programs to the laptop and taught the teacher how to use them. The teacher was especially excited about the typing and encyclopedia programs, and expected to use the laptop much more often. Also on this trip, the team removed a broken inverter and replaced a broken charge controller from the church and changed the system to DC. Because at least 2 different Sundaya Apple charge controller units have failed, they appear not to be robust in Santo Domingo’s humid environment. The team also returned to Santa Librada to check existing systems and found a minor problem: since its installation six months before, the refrigerator-freezer had warmed two to three times from power losses while on the freezer setting. Because it is mainly used to store meat for the majority of children in the community since they live too far from school to go home for lunch, it is imperative that the refrigerator-freezer is maintained at a safe temperature. Before the next trip, the team plans to reexamine the freezer system and determine whether another solar panel is needed. In the meanwhile, the team advised the Santa Librada solar committee to maintain the refrigerator-freezer on the refrigerator setting to keep it cold consistently.
Wastewater Treatment Project
Since December 2005, five teams of ESW-NU members have traveled to Portobelo to gather essential data on the water quality, soil conditions, topography, and material pricing. Each of these teams also met with community members including the mayor of Portobelo to present and discuss improvement plans for the local wastewater treatment. The most recent trip to Portobelo occurred in September of 2008. ESW-NU hired a Panamanian company to empty the septic tank of its existing sludge, which had never been done according to the closest resident. The process required three tankers with pumps and four workers over the course of two days to completely empty the tank of over forty years of sludge accumulation. Workers removed large rocks, debris, and trash from the septic tank and unclogged one of the inlet pipes. The septic tank now has an acceptable detention time of the wastewater, allowing for separation of solids. While the current effluent is expected to be much cleaner than before, further treatment of the wastewater must occur to meet government regulations.
Students in three courses at Northwestern University have investigated alternative solutions for wastewater treatment in the Guinea neighborhood of Portobelo. The chosen solution includes three phases: modification of the existing septic tank, construction of a trickling filter to refine the septic tank effluent to within government regulations, and construction of a sludge drying bed to treat sludge removed from the septic tank. The final design has been presented in detail in an Environmental Impact Statement. This report will be sent to ANAM, the Panamanian environmental regulatory agency, for approval before ESW-NU begins construction.
The first phase of construction is the modification of the septic tank. Simple rerouting of the flow by replacing the pipes will be sufficient to achieve the desired effluent from the tank (before filtration). The water currently flows in parallel through two adjacent chambers. The modification will replace the pipes to direct the flow through each chamber in parallel to increase solid separation. Sludge removed from the tank during periodic cleanings will be transported to a sludge drying bed. The location of the drying bed was found with the help of Portobelo’s mayor. The site is a landfill shared with Santa Isabel and is maintained by both municipalities. Its high elevation, large size, and remote location make it an ideal location for the sludge drying bed. The dried sludge can be either used as fertilizer or disposed into the landfill. The final phase of construction is the trickling filter, which will refine the effluent from the septic tank. Water trickles through a filter covered with a layer of bacteria that act to further refine the septic tank effluent. This is the most complicated component of the wastewater treatment system, and must be constructed from scratch. The trickling filter requires pumps, valves, filter media, and PVC pipes. Due to the complexity of the filter, construction is scheduled for the summer of 2009. This will allow for additional time to finalize details of the design and obtain additional assistance from professional experts in wastewater engineering.
Solar-Generated Electricity Projects
This year, the solar project team plans to complete house electrification in Santo Domingo and modification of the refrigerator-freezer system in Santa Librada. ESW-NU is responsible for purchasing and delivering four more sets of components to electrify individual houses in Santo Domingo, and will use funds raised on the site www.globalgiving.com to pay for components. A local Panamanian government representative has pledged to purchase components for the remaining 10 houses. Since the solar committee is fully trained, they will be responsible for installing the 14 sets of components when they arrive. However, at least two more trip teams will travel to Santo Domingo to check on progress and on the maintenance of the existing systems. A team will also visit Santa Librada within the next year to troubleshoot the refrigerator-freezer system. ESW-NU plans to continue working in Chagres National Park after these tasks are completed, expanding ways of helping both communities and working with other communities in the park as well. The Phase II P3 grant has helped fund a great deal of the solar project over the past year and a half. Thanks to the funding, Santo Domingo’s families are beginning to have light at night, their children now have more opportunities to learn, and the community’s solar committee has new, marketable skills. When Santa Librada has visitors staying at the school such as the traveling doctor or priest, they can continue to work or meet in the evenings, and the community’s children have safer food to eat every day at school. ESW-NU students and their advisors have been grateful for the opportunity to work with these communities and for the valuable learning experiences they have had throughout the projects.
Wastewater Treatment Project
Construction is scheduled to begin in March 2009 with the modifications to the septic tank, pending approval of the Environmental Impact Statement. ESW-NU will oversee construction, which will be carried out by local workers under the supervision of an experienced foreman. FADE, a local development organization, has offered assistance with the hiring of these workers. If time and resources allow, the sludge drying bed will also be constructed in March 2009. Observation of the sludge removal process caused the ESW-NU team to reconsider asking the locals to empty the tank on a volunteer basis every six months. The new goal is to have a city employee dedicated to the maintenance of the town’s septic systems, who will empty the septic tanks using a pump connected to a large plastic tank in the bed of a pickup truck. The tank will then be transported and emptied into the drying bed. This idea will be proposed to the mayor during the next trip, and ESW-NU will consider furnishing the pump and plastic tank. The project will conclude with construction of the trickling filter during the summer of 2009. Once the filter is completed, the town of Portobelo will have a sustainable, functioning wastewater treatment system which its residents helped construct. It is the hope of ESW-NU that the work done for the Guinea wastewater treatment will prove economically feasible and adequately sustainable so that similar small-scale wastewater treatment plants will be implemented in other Portobelo neighborhoods by FADE, ESW, or other agencies.
Common goals and accomplishments
Both the solar projects and the wastewater project have provided ESW-NU members and the communities with whom they’ve worked with valuable learning experiences. The theme of education with implementation has proved fruitful in the short term, and our team expects the effects to make a significant difference in the long term as well. For example, the communities who have received solar-generated electrical systems will have not only immediately improved quality of life, but also the empowerment of having a local solar committee whose members know how to install and maintain their systems independently. And because local workers have now pumped the septic system in Portobelo and will construct the new parts and modifications of the system, these people and the involved government employees will have gained the knowledge they need to continue maintaining their system and keeping their water clean after the project has ended. Trip teams have also worked to help educate children in each community about the importance of protecting the environment and keeping their water clean, speaking to the children and also providing books and posters about these topics. Exposing children to these ideas and these projects at an early age will help to create a new generation more conscious of environmental issues and solutions. All of the educational components of these projects are crucial in ensuring that the communities will continue to have working systems and can even use their skills to help other communities to implement similar projects.