When it comes to the thorny issues of finding new energy sources for an energy-hungry continent, local innovations unearth surprising solutions. Nigerian-born researcher from the Department of Pharmaceutical and Medicinal Chemistry at the University of Nigeria Nsukka (UNN), Justus A. Nwaoga, has discovered new features of the organic medicinal African weed, Mimosa Pudica, and brought it into a project development that aims to turn a common weed into renewable solar energy for the continent.
Earlier this year, the researcher has secured a patent for the development of solar cells from weed, commonly known as Mimosa Pudica, which translated into English language means “touch me not” or “sensitive plant” referring to its sensitivity to touch and solar light.
Chosen from more than 900 applications from 45 different countries, Nwaoga’s research placed him among the top ten innovators in Africa at the second edition of the “Innovation Prize for Africa” held in South Africa in May, 2013 for developing practical solutions to some of the continent’s most intractable problems.
His research has discovered that Africa’s weed, Mimosa Pudica, found throughout tropics, apart from its many traditional medical uses, embeds solar properties suitable for the production of solar cell and, thus, electricity.
Fascinated by the properties of the plant, Nwaoga embarked on a journey to discover why the leaves of the plant close when touched during daylight only to open several minutes later. Investigating the effect of the artificial light on the leaves at night, the researcher discovered that they unfold only to natural solar energy which led to his conclusions that the plant could provide a new way of tapping into the sun’s energy and provide solar cell electricity.
While observing these properties of the plant, he became determined to isolate the compound responsible for the responses of the leaves to the solar light and has discovered “the black silicon,” which, according to the researcher, is much more sensitive than the silicon currently used in solar panels.
After various unsuccessful attempts to transform the Mimosa Pudica extract into energy potential, Nwaoga and his team finally managed to generate a steady direct current to light a 4.5-volt lamp after correctly understanding the chemical makeup of the extract, which was previously too strong therein corroding the zinc or cooper plates.
The breakthrough in their research has allowed them to construct a Mimosa Solar Panel with the plant extract in such a way that the electrical potential of the cells can be restored on the exposure to direct sunlight after they have been discharged. Nwaoga explained that solar cells constructed with the weed extracts and exposed to sunlight were found to accumulate solar energy which was transformed into electrical energy and such innovation could be used for various domestic, military and industrial appliances among which a solar rechargeable lantern.
According to the researcher, an advantage that solar panel made from the Mimosa extract has over the traditional silicon solar panels is its sensitivity and ability to withstand greater intensities of light. In an African continent, traditional solar panels often break or fail due to very high sun intensities. Since solar panels made from “black silicon” can withstand greater intensities of light, they provide a more suitable alternative for African electrical power shortages.
Furthermore, whether solar electricity would be cheaper if generated from the weed than from traditional silicon panels, the researcher is undeniably positive. About 0.5 ml of one per cent concentration of mimosa extract can give one 0.25 volts or more when properly set. Since the product is locally grown and abundant, its cost would be much cheaper than for the imported silicon panels.
It may be noted that the researcher has already secured earlier this year a patent for the sole use and advantage of inventing Mimosa Pudica solar cells and the Mimosa Pudica extract has been accepted as a new material for solar energy development.
Will it become a popular solution to the African power shortages? It is still too early to say. However, the innovation undoubtedly testifies of the ability for Africans to find innovative solutions to the energy-hungry Africa.