Engineering Researchers Find When Power Goes Out, Pollution Rises

Researchers in Carnegie Mellon University's Department of Engineering and Public Policy have found that when the power goes out in sub-Saharan African countries air pollution rises. 

EPP Ph.D student DeVynne Farquharson and professors Paulina Jaramillo and Constantine Samaras recently published their findings in Nature Sustainability.

"While there are many sources of air pollutants that affect air quality," Farquharson said, "we found that reliance on backup diesel generators can lead to increased air emissions. Our results suggest that, in some countries, air emissions resulting from reliance on backup generators can be even larger than annual emissions from centralized power plants."

Even those with access to electricity experience challenges getting it to work when they need it, the researchers said. In Nigeria, for example, insufficient generating capacity, poor conditions in existing power plants, and problems in electricity distribution networks can often leave Nigerian consumers without power for more than half the time, annually. In other words, when they go to switch on the lights, there's only about a 50 percent chance they will actually come on.

Without reliable access to electricity, residents of these countries are forced to take matters into their own hands - often in the form of on-site, diesel backup generators. The use of these generators, the team found, increases fossil fuel energy consumption by a factor of 1.5 to 1,000, compared with current grid levels throughout the region, and cost customers millions of U.S. dollars annually. But most significantly, the emissions from these generators have a substantial negative impact on the health of their users in both homes and businesses.

"Air pollution is a silent killer in sub-Saharan Africa," Farquharson said. "Recent estimates suggest that poor air quality leads to an additional 450,000 infant deaths in the region."

The United Nations has declared access to electricity as one of the UN's Sustainable Development Goals. But as the team's research has shown, unreliable delivery of electricity can lead to additional consumer costs, limited economic benefits and increased environmental impacts. The team's research highlights how important it is to ensure that governments invest in reliable access to electricity, in order to save the lives of all those affected by the significant contribution of diesel generators to air pollution.