The hidden power of cell towers
New Scientist magazine reports that cellphone towers can provide not only welcome communication to rural communities in developing countries but lifesaving water purification and vaccine cold storage as well.
In the case of vaccines, two million people die of vaccine-preventable diseases such as polio, measles and hepatitis annually.
Vaccines for these diseases have to maintain a "cold chain" - keeping them refrigerated from manufacture to end-use.
The biggest logistical hurdle is getting these vaccines from central supply depots to rural medical facilities with unreliable or no power.
Many rural villages rely on one of the estimated 639,000 off-grid solar and wind powered cell towers for their mobile signals.
Harvey Rubin of the University of Pennsylvania estimates that towers generated an excess 5 kilowatts of power on average while the refrigeration requirement for the vaccines should take only 2 kilowatts of power.
Water purification is more energy intensive than vaccine storage but could also be addressed with excess electrical capacity.
In fact, as network operators recognize the uses of their off-grid towers to charge mobile handsets, household batteries and rechargeable lanterns, they see business opportunities in powering entire villages.