About 2 billion people in developing countries worldwide lack electricity, which in turn impacts the health, ecology and safety of rural households. Many are forced to rely on inefficient and environmentally damaging kerosene lamps: Developing nations alone burn 470 million barrels of oil and release about 400 billion pounds of greenhouse gases into the atmosphere as a result of using kerosene. Other sources of light fuel include cow dung, precious forest firewood or crop residue.
But in a massive new study carried out in Gujarat, one of Western India's poorest states, hit hard by drought in recent years, researchers have proposed that solar photovoltaic lanterns could represent a solution for rural communities with insufficient lighting. This is particularly true in India, where the average number of sunny days ranges from 250 to 300 per year, generating a solar energy equivalent greater than the country's total energy consumption. With India's large and growing population, solar lanterns, using the country's abundant sunlight, could be the cleanest and most practical energy alternative available.
"These lanterns have the potential to replace the candles, kerosene lamps and hurricane lanterns commonly used by villagers," wrote the two researchers at Taiwanese universities, Govindasamy Agoramoorthy of Tajen University and Minna J. Hsu from the National Sun Yat-Sen University, who led the study. "Furthermore, they can be used outdoors in agricultural fields during irrigation and harvesting, for fishing at night, and many other farm-related activities."
Their article, "Lighting the Lives of the Impoverished in India's Rural and Tribal Drylands," has been published online in the journal Human Ecology. Between January 2004 and December 2007, the researchers gathered data on the benefits of the lanterns from 25 villages in the district. All demographics were considered: In addition to recording data on names, heads of households, poverty level, family size, number of children and students, the researchers also tracked household savings (in kerosene and electricity costs) before and after the introduction of solar photovoltaic lanterns. And rural women were interviewed at least a month before receiving the lanterns and a month after.
The lanterns — provided by the nonprofit Sadguru Foundation — cost $87.50 and consist of a photovoltaic module connected to a storage battery, charge regulator, compact fluorescent light source, inverter, and a switch. One lantern can provide light for more than six hours after a full day's charge and can save about 100 liters of kerosene per year, which in turn reduces CO2 emissions.
During the nearly four years of tracking use, the researchers found that expenditures for kerosene and electricity dropped significantly after the introduction of solar lanterns. Overall, each household saved $91.55 in energy costs per year, which the researchers called "a huge savings on an annual family income ranging from $150 to $250."
In addition, with the six hours of light supplied daily by the solar lanterns, the researchers found the average number of hours students in a household spent studying increased from 1.47 to 2.71. "This increase in study hours has had a positive influence on students' performance at school," the researchers wrote. "Likewise, women are able to perform their routine household work both indoors and outdoors during power outages."
The research comes at a critical time for India: The commercial solar photovoltaic market has increased from 10 firms in 1992 to 60 in 2002, and the resulting competitiveness has pushed the prices of solar lanterns to their lowest levels in the world. But the lanterns have been slow to catch on. "Even though India's Ministry for Non-Conventional Energy Sources (renamed the Ministry of New and Renewable Energy) encourages solar photovoltaic technologies ... community response has been poor — only 365,000 solar lanterns have been installed under the program promoted by the ministry," the researchers noted.
Nonprofit agencies, foundations across the international community and even celebrities ranging from Bollywood stars to Bon Jovi, however, have begun to take notice. Especially encouraging to the researchers is the news that the United States-based nonprofit Energy and Resources Institute, with $30 million in funding for a four-year period from the Clinton Global Initiative in 2007, has engaged in a sustainable development project that aims to provide solar lanterns to thousands of rural households across India. "If implemented efficiently, these projects could not only improve the quality of life for India's rural poor but also enhance sustainable use of the environment," the researchers conclude.
Miller-McCune has previously looked at alternative lighting solutions — including photovoltaics — for the developing world. John Perlin gave an overview of photovoltaics and examined a German program trying to create a solar cell marketplace. And Lindsey McCormack profiled a researcher who patented a combination of familiar technologies — flexible solar panels, LED lights and a lithium cell phone battery — to form a cheap, renewable lighting system for developing nations.
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