Electricity from rural cellphone towers in poor countries could chill vaccines, saving 5Â million lives every year, say Harvey Rubin and Alice Conant
EVERY year, at least 2 million people die from vaccine-preventable diseases such as polio, measles and hepatitis. A further 3 million die from diseases spread by unclean water. Both of these big problems ultimately come down to the same thing: a lack of energy infrastructure in the developing world. We propose a solution that could be implemented immediately.
The 2 million vaccine-preventable deaths do not occur for lack of vaccines, but because of inadequate distribution. To work properly, most vaccines must be kept cold. That means constant refrigeration from the point of manufacture to the point of delivery, often a rural location. The series of storage and mobile refrigeration units required to achieve this is called the “cold chain”.
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Refrigeration requires energy, and in countries with a limited energy infrastructure, maintaining the cold chain can be an overwhelming challenge (Vaccine, vol 12, p 1423). A 2007 study in rural India found that 90 per cent of local health centres suffered frequent power failures, and that only 45 per cent of these had a back-up generator ().
Several other studies come to similar conclusions. In Nigeria, for example, inadequate energy infrastructure causes significant loss of vaccine potency between the National Cold Store in Lagos and rural vaccination centres (Public Health, vol 110, p 325).
Although the cold chain is not the only impediment to immunisation, it is a major one. A technology that allows the cold chain to better penetrate rural regions would have a big impact.
Many of the 3 million people killed by water-borne diseases are children. Their deaths are a direct result of the fact that more than a billion people have inadequate access to clean water and 2.6 billion lack adequate sanitation. Access to clean water requires water treatment, an energy-intensive process that is often impossible because there is no reliable local energy source.
Both problems demonstrate the urgent need for a rural energy infrastructure in the developing world. Our project, based at the University of Pennsylvania in Philadelphia, proposes to tackle this problem by hitching it to a juggernaut of global technological development – cellphones.
Cellphones are the fastest spreading technology in the world. According to the United Nations’ , approximately 75 per cent of the world’s rural inhabitants are now covered by a cellular signal and close to 100 per cent will have coverage by 2015.
Cellphone networks rely on cell towers, and towers need power. This is usually supplied from the electricity grid. In recent years, however, cellphone networks have increasingly spread into . These use stand-alone cell towers powered by diesel generators and, increasingly, solar and wind.
The off-grid network is growing fast. The industry trade association, GSMA, estimates that by 2012 there will be 639,000 off-grid cell towers in the developing world. These represent a potential new energy infrastructure in locations with no access to the electrical grid.
Our proposal is simple: use surplus energy from off-grid cell towers to power cold chains and water purification systems. If we succeed, by 2015 everybody in the world could have access to vaccines and clean water and we could save 5 million lives a year.
“If we succeed, by 2015 everybody in the world could have access to vaccines and clean water”
Although supplying power is not part of the network operators’ business plan, GSMA recognises its potential. It promotes the idea through an initiative called “Community Power” and its “a significant opportunity exists to provide… energy to people in the developing world who live beyond the electricity grid”.
With the support of Community Power, network operators are already exploring ways of using their surplus tower power to charge mobile handsets, household batteries and rechargeable lanterns. They also recognise the potential for powering entire villages.
Our first aim is to solve the cold chain problem due to its minimal energy requirements. Cold-chain refrigerators require a minimum of 8 hours of electricity a day, and even the most energy-hungry models require no more than 2 kilowatts of power. Off-grid cell towers produce about 5 kilowatts of excess power on average, so this should be achievable with no negative impact on the cellphone network.
Other cold-chain solutions are being explored, including heat-stable vaccines, solar powered refrigeration units and immunisation teams with refrigeration units in their cars. However, these methods are expensive and some require many more years of research.
Water purification is more complicated. There are numerous purification methods, so the energy requirements are not as easy to calculate. In addition, infrastructure for transporting water is often lacking. But if cell towers can provide the energy for water purification and are then integrated with transportation projects, clean water could be made available to all rural locations in developing countries.
Our idea has received enthusiastic support and we are starting to put the wheels in motion. The next step is quite straightforward. We want to implement a pilot project in collaboration with the cellphone and pharmaceutical industries and a local healthcare system. We are ready to start immediately – we must start immediately – and we are available to provide further information or to receive suggestions.
Update: Due to an editing error, in the first version of this story we incorrectly stated that the power consumption of a cold-chain refrigerator is less than a clock radio
