N. Hanson[20] * and B. Newhouse1
1 Peace Corps Cape Verde, 373 Prainha, Praia, Ilha de Santiago, Republic of Cape Verde
* Corresponding Author, nfhanson@gmail. com

Abstract

A simple solar still project was introduced into the curriculum of a secondary technical school, [Escola Tecnica — Grao Duque Henri] in Cape Verde, to enhance the education quality and test economical, green solutions to the country’s water supply problems. While Cape Verde has modern educational facilities, teaching methods rarely focus on the start to finish implementation of ecological projects and encouraging student creativity. While the still produced a maximum of just 2L/day, an output insufficient for a person’s daily water needs, the project has shown students and faculty the advantages of an environmentally sustainable project. Students additionally researched an improved solar still design as part of their lesson plan. Consequent interest in solar fuelled projects led to student involvement in the construction of solar box cookers, which harness the sun’s rays to cook food. The completion of the solar still pilot project has inspired Cape Verdeans to research additional sustainable projects and to expand the practical applications of their education. The successful implementations of environmental projects that have utility motivate students and teachers to learn.

Keywords: capacity building, solar still, environmental projects, development

water sources, and pricey desalination, Cape Verde’s ample access to sun and salt water makes it ideal for solar still implementation.

During the academic year of 2007/2008, a solar still prototype was designed and implemented in classes at Escola Tecnica — Grao Duque Henri [one of the four Secondary Technical Schools in Cape Verde], to teach students and colleagues about the potential to produce potable water from seawater using only solar energy. The design was based on Farrington Daniels book on Direct Use of the Sun’s Energy.4 The second trimester focused more on educating the students on solar distillation and on designing an improved model to achieve higher production rates. A new solar still was designed, using cascading steps and constructed during the 3rd trimester of the school year.

Approximately eight years ago, four Secondary Technical schools were built to educate technicians, accountants, and labourers, to better prepare students for higher education and the growing economy. Within two years after completion, Escola Tecnica — Grao Duque Henri was operating at capacity.

Implementation of the solar still project at the Escola Tecnica in Santa Catarina increased the students’ knowledge of solar energy and their motivation to learn. It also provided technical skills to prepare graduating students for potential job opportunities. The three of the most challenging subjects are Mathematics, Portuguese, and Physics. Understanding in these subjects can be improved by integrating environmental projects that make it fun to learn and that have tangible results.

In the sections to follow, the solar still prototype and its integration into the curriculum through practical labs will be presented along with the improved solar still specifications. Further on we will describe how the solar still project was disseminated into other classes. The objectives are to improve the students’ knowledge of the benefits of solar energy and to increase their interest in related academic subjects such as physics and math and to test solar still designs. The execution of the solar still project at the school encountered many successes and obstacles. Methods to resolve these obstacles will be presented as well. [21]

Fig. 1. Solar still prototype before alterations

The school administration approved the project only as an extra-curricular activity. The solar still prototype was introduced in the 11th grade practical labs during the first trimester of the 07-08 academic year, in collaboration with practical lab professors. Each of the four 11th grade classes — approximately 22 students each — received a detailed lesson on the science of solar distillation and a copy of the prototype proposal. To reinforce comprehension, each student was asked to draw the still plans prior to construction. Throughout the 1st trimester the students constructed the solar still shown in figures 1 & 2. At the beginning of each phase of construction, students were taught the relevant technical and theoretical aspect of still design; for example: sketches and take-offs of the basin formwork and the reinforcing metal mesh, calculations for volumes of concrete necessary to pour the still, construction details of the collection trough and interface with the formwork. For ease of construction, groups of five to six students were rotated through each phase of still construction.

The cost for the complete solar still prototype was 18,500 CVE (Cape Verdean Escudos) [~245USD, at the exchange rate of 75 Escudos to 1 Dollar]. Daily operating costs are virtually zero. The still needs no monitoring except for the daily removal of fresh water, cleaning of the glass, and weekly replenishment of sea water in the reservoir.