In modern times, Sudan has been ravaged by unspeakable violence that goes far beyond Darfur. The country has been in civil war for 41 of the last 55 years, leading to more than 2 million deaths and making it the bloodiest conflict since World War II. Many more were displaced, including a group of thousands of young boys who were separated from their families and forced to flee hundreds of miles to refugee camps in Ethiopia and Kenya. This group became internationally known as the Lost Boys of Sudan. This journey is close to home for one of our group members, senior Mou Riiny, who, at the age of 7, was one of the youngest of these boys. Mou’s path is shown in the map below.
A glimmer of hope came in 2005 when a peace treaty put an end to the civil war and paved the way for the South’s recent vote for independence. With South Sudan now preparing to become the world’s newest country, it is imperative that we help them become self-sufficient to prevent a return to violence.
Engineering a Brighter Sudan aims to spark the opportunity for progress and social development that South Sudan desperately needs by bringing sustainable electricity to schools and communities in the region. Electricity carries with it a world of benefits for these rural villages, including the alleviation of poverty, reduction of illiteracy, and help for the local economy by providing opportunities for entrepreneurship. By giving these people the tools for progress, we can help a newly independent South Sudan prosper as a country.
The system will be used to power indoor lights for 10 classrooms (25′ x 20′), outdoor lights for a field (75′ x 150′), 10 laptops, and a community charging station. A breakdown of the estimated daily electricity usage for each component is shown in the chart below.
This chart makes it possible to determine the size of the system. The size of the battery bank can be found by taking the area under the curve and dividing by the inverter efficiency (.9) and the discharge limit (50%). To power the system for one 24 hour cycle, a 48 Volt battery bank is required with a total rating of 1,220 amp-hours (4 parallel connections of 305 amp-hour batteries). To charge these batteries, a 5.4 kilowatt solar panel array is necessary.
The wiring diagram below shows all of the major components in the final prototype system at the University of San Diego.
Solar panels are used to convert energy from solar radiation into electrical power in the form of current. About 90 Volts is generated through each solar panel array. The charge controller steps down this voltage to roughly 48 Volts to charge the batteries and provide power to the input of the inverter. The inverter takes direct current from both the solar panels and the battery bank and converts it to standard alternating current (230 Volts, 50 Hertz for Sudan). This is then used to power lights, laptops, and standard outlets.
For safety, all major electrical components are grounded. In addition to this, circuit breakers are placed between each component to assure that the equipment and wires are not overloaded. The wiring diagram below shows the grounding scheme as well as all of the major circuit breakers and disconnects.
The inverters, charge controllers, and batteries (via the FlexNET DC) are constantly gathering data about the performance of the system. These data are sent to an OutBack HUB and MATE and uploaded to a laptop computer. We wrote a program in LabVIEW to monitor the system in real-time. The front panel of this program is shown below.
This program gives the user information about the power flow through each major component of the system. In addition to this, it monitors the battery health and the power production of the solar panels throughout the day. Should something go wrong, the program allows you to shutoff the inverter using the emergency shutoff button on the bottom right. This program makes the system much more understandable to the user and places all of the information about the system in one place.
There are two phases to the project. The first phase consisted of the development of a prototype system at the University of San Diego. For this, a scaled model of the final system was developed and demonstrated to the campus community. The system layout diagram is shown below. The black lines represent neutral wires, the red lines represent positive wires, and the orange lines represent the flow of information through the system.
We successfully demonstrated this system to the San Diego community during the Spring Engineering open house on May 6th, 2011. The only three things that were scaled down in this system were the solar panels, battery bank, and the loads.
The solar panels for the system were located on the roof of the Engineering building (shown on the left). These sent power to the rest of the components located in one of the rooms in the building.
The budget for our project can be seen below. As you can see, the estimated cost of the entire endeavor is roughly $70,000. Through many generous donors, we have already received nearly $50,000 and are well on our way to making this project a reality.
We would like to thank all of our sponsors for their kind support. AM Solar was our first major sponsor and have provided us with a $5,000 matching grant, technical support, and contact to other companies. P-2 Lighting provided all of the energy-efficient lights that will be used in the school as well as a shipping container to send materials to Sudan. OutBack Power provided us with the inverters and wiring boxes for the final system. Jinko Solar donated 6 kW of solar panels to be used in Theou. We have also received cash donations from various sources.
Schedule and Milestones
Major Milestones (Fall Semester)
- √ October 19th, 2010 – Project Proposal and Presentation completed
- √ December 2nd, 2010 – First prototype developed to power lights and laptops
- √ December 9th, 2010 – Preliminary Design Review and Oral Presentation
- √ December 10th, 2010 – Poster Demonstration at Engineering Open House
- √ February 15th, 2011 – Ability to communicate with MATE using LabVIEW
- √ March 22th, 2011 – Critical Design Review and Presentation
- √ April 28th, 2011 – Full working scaled system
- √ May 6th, 2011 – Demonstration of prototype at Engineering Open House
- √ January 8th, 2011 – South Sudan votes overwhelmingly to secede
- October 2011 – Order all Components for Final Sudan System
- December 2011 – Ship Materials to Sudan
- Summer 2012 – Travel to Sudan to Install Final System