This is just one of the findings of University of Michigan researcher Brian Min, who has analyzed thousands of satellite images taken every night over the last 20 years in India.
His massive project has involved tracking light output of more than 600,000 villages over 8,000 nights to study how the access and use of electricity varies across the country.
"India has made great progress in the last two decades, but there are still vast areas that remain in darkness," said Min, U-M assistant professor of political science.
Many rural areas in states such as Punjab and Haryana have achieved 100 percent electrification and have become much brighter. But other states, such as Jharkhand, Uttar Pradesh and Bihar, have seen only small improvements.
The central state of Madhya Pradesh has claimed that most of its villages were electrified by 2011. But the night lights tracked by satellites tell a different story. They show that Madhya Pradesh is one of the regions with highest intra-state variation, with several dark districts, many within tribal areas.
Jharkhand is another eastern state which has claimed 95 percent rural electrification by 2015, but the map shows a much more gradual electrification, with most night lights coming from urban areas.
One can also see an increase in the light output around Hardoi, a city in Uttar Pradesh, after the state energy minister was elected from there in 1998-2001. But after the minister left his cabinet post in 2001, there was a cutback in light output from his constituency.
"In India, issues like electrification are driven by political considerations," Min said.
The result is collected in a Nightlights website created in partnership with the World Bank, U.S. National Oceanic and Atmospheric Administration and Development Seed. It lets users zoom in on states and districts to see the change over the last couple of decades.
"Even a villager can now access the maps to see how electrification has impacted their village," Min said.