Bouteille de Lumière: Solar Bulb in Yaoundé & Douala

To learn more about what is going on, go through the links below:


Last Achievement Report

Executive Summary

A common characteristic of informal settlements such as Bonaberi in Douala and Briqueterie in Yaoundé is the lack of indoor lighting during the day.  Because of security concerns, the sizes of windows are kept to a minimum. This prevents the use of natural daylight  leaving indoor spaces in darkness. Candles, kerosene lamps  and electric bulbs  –  for those who can afford  electricity-  are  used  during the day resulting in additional  cost implications  as well as the indoor air pollution associated with the use of both candles and kerosene lamps. The lack of sufficient ambient lighting during the day hampers the ability of communities in informal settlements to carry out household chores and other important tasks.

The solar bulb  is an  innovative passive lighting system based on a transparent plastic bottle filled with water. It is  fitted  into  the  corrugated iron roofs  found in informal settlements. On installation, one-third  of the bottle  is  left  outside the roof while the  remaining two-thirds  protrudes into the house.

Sealant is applied around the  bottle and the roof to ensure that it remains weatherproof. When properly installed, the water inside the bottle with its refractive properties produces a light similar to a normal electric light bulb. A small amount of bleach is added to the water to ensure that it is kept clear and free from algae and that high quality  light is produced for a  long time. The plastic bottle used for making the construction  the solar bulb can either be a recycled soda bottle or a new one. Solar bulbs have successfully been used in slums in Manila to provide  indoor day lighting  to several communities.

The lighting produced by one solar bulb containing one and half liters of water is equivalent to the light produced by a 50W incandescent light bulb. Using this technology,  households  are able to  save on energy previously used for lighting during the day.

This project is being implemented under the framework of GENUS with funding from UN-Habitat

Objective of the project

The main objective of this project is to provide access to a clean lighting system to  people living in informal settlements.  Its specific objectives are:

  • To reduce the need of artificial lighting during the day;
  • To promote energy efficiency in slums; and
  • To fight energy poverty.

Households  in informal settlements spend more than one third of their income on energy related expenses including illegal electricity, kerosene and batteries. The Solar Bulb project will enhance the productivity of  the beneficiary households  by providing them with access to high quality day time lighting at no extra expense.

Expected Accomplishments

The successful delivery of the solar bulb project will have the following expected accomplishments:

  • 3,000 units of the solar bulb installed in households in  Douala  and  Yaoundé  reducing their expenditure on energy during the daytime while ensuring that the household energy demand is met;
  • Reduction in indoor air pollution resulting from the use of kerosene lamps to provide lighting during the daytime;
  • Improved knowledge of demand-side management and the design, assembly and installation of solar bulbs.

Implementation Strategy

UN-Habitat will be responsible for providing 77% of the total funds to  FCTV to enable the installation of  3,000 units of the solar bulb. UN-Habitat will also monitor the implementation of the project and ensure that the project reaches its intended beneficiaries. FCTV will report on the project monitoring and will provide an evaluation of the performance of the new technology as well as a detailed report on the impact assessment of the project within the community.

FCTV will also be responsible for the following:

  • Providing in-kind contribution of 23% of the total project budget;
  • Conducting  a baseline study to  identify  the different sources  of  energy  used  by  the  project’s beneficiaries as well as their expenditure on daytime lighting;
  • Awareness raising among the beneficiaries;
  • Installation of 3,000 solar bulbs in households;
  • The submission of substantive progress reports on the project and a final report;
  • Mapping out the  locations of the solar bulb installations using GPS and Google Map  to ensure that all the installations are in the informal settlements;
  • Provide the list of the beneficiaries;
  • Keeping  records on the location as well as data on beneficiaries including ID numbers and contact details (phone numbers) to enable verification of solar bulb installations made by the project;
  • Conducting a project impact assessment on households two months after the installation of the solar bulbs.  The impact assessment will evaluate the difference that the project has made for the beneficiaries;
  • Prepare guidelines for the scaling up of the project to reach more beneficiaries;
  • Joint evaluation with UN-Habitat to ensure that solar bulbs have been installed and are fit-for-purpose.