Technology Innovation: Solar-heated Showers at the Bolivian Highlands

This case study showcases how how low-cost technology can work to solve a special environmental problem. The background, design, implementation, and lessons learned are given regarding the introduction of solar-heated showers by UNICEF Bolivia.

The challenge 

How low-cost technology can work to solve a special environmental problem is the subject of this case study. The Bolivian highlands are chilly for most of the time. The temperature averages 7 degrees Celsius and ranges from 18 degrees during daytime in summer to minus 18 degrees at night in winter. Bouts of icy rain are common with snow fall during winter. 

Under these conditions, water in gravity-fed systems and streams has a very low temperature. In the winter, people and particularly children, prefer not to wash themselves in the very cold water. However, fuel is expensive and fire wood scarce so that water is normally not heated for bathing.

Infrequent bathing in combination with unhygienic conditions, cold weather and harsh winds cause many children in the Bolivian highlands to suffer from skin diseases, upper respiratory infections and regular episodes of severe diarrhea. Official statistics show that in the highlands, about one quarter (27.2 %) of the children under five years suffer from diarrhea while scabies is prevalent among about one-fifth (19%) of the school children.

Under these circumstances, UNICEF Bolivia decided in the late 1990s to develop some pilot models of solar-heated showers for highland populations. These showers are usually constructed in school compounds to allow school children to bath in warm water during school hours, under supervision of the school teachers.

The design

The solar-heated showers are designed with a view to easy construction, use of low-cost materials and easy maintenance. Water is heated by the sun: 100 meters of one-inch diameter polyethylene pipe is filled with water and exposed to the sun. In some designs, the polyethylene pipe is protected by windows covered with meshing. Because Bolivia is located in the southern hemisphere, all showers are oriented towards the north to catch the rays of the sun. 

The capacity of each solar panel is 46 liters. Since most of the schools in the highlands are small, rural schools, this capacity is sufficient. Only in the bigger schools, more than one double shower unit is built. The costs of construction of one double, solar-heated shower is US$ 1,700.

Implementation

The solar heated showers have been developed within the water, sanitation and hygiene component of the Andean Programme of Basic Services against Poverty, called PROANDES.  PROANDES arose from a sub-regional initiative promoted by the UNICEF Regional Office for Latin America and the Caribbean. Its objective is to support Andean countries to reduce the principal manifestations of poverty amongst priority groups of their population. The program is being implemented in five countries: Colombia, Ecuador, Venezuela, Peru and Bolivia. PROANDES began implementing actions in Bolivia in 1989. 

Thus far, more than 350 solar showers have been constructed. The construction is generally being done by community members themselves with technical support and supervision from an NGO and/or municipal technical services. For the period 2006-2009, financing for an additional 225 double cabin solar-heated showers at school compounds has been secured.   As a result of this work, other organizations in Bolivia have also started to construct the solar heated showers using a design similar to the one UNICEF developed.

Lessons learned

Evaluation showed that whenever the showers in schools are functioning, they are being used by school children and their teachers.

Most children will use the shower to wash their hair with shampoo. Where it is difficult to motivate parents to provide soap for hand washing, even the poorest families seem to provide the children with small sachets of shampoo. The result is that at the same time as they wash their hair, children also wash their skin with the (shampoo) soap that drains from their hair. 

Visual observation shows that children in schools with functioning showers, suffer less from skin diseases and skin infections than in schools without showers. However, no study has been done on this or other possible impacts. 

Normally school boys take showers at different hours or days than school girls. Generally, showers are being used by two children at the same time so they can help each other. For the younger children, teachers help them while taking a shower.

One real challenge is the quality of construction and flexibility in design, taking into account the local situation. Deficiency in these, and in supervision mean that some of the showers are not correctly constructed and never have worked properly.  Although Operation and Maintenance training, manuals and equipment is being provided, there is still a need to improve this component.