electricity gap
n. A substantial difference in electricity use and availability, particularly between urban and rural areas or between first- and third-world countries.
India has an exceptionally wide electricity gap: About a fourth of its citizens, some 300 million people, lack access to electricity.
Vaccines unable to be stored without refrigeration, students closing their books after dark, and smoke-filled homes thanks to wood or coal burning devices are some of the issues plaguing 69 percent of sub-Saharan Africa due to the shortage of electricity across the continent. As African governments and international partners seek to remedy the electricity gap, huge potential for renewable energy sources, such as solar, wind and geothermal, have investors from African countries and around the world considering a cleaner solution.
—Jordan Stutts, “To close its energy gap, Africa should think clean,” Foreign Policy Association, February 06, 2014
And if you drill down a bit into the electricity gap it actually seems to get smaller: the largest one percent of homes, averaging around 6400 square feet, use 2.5 times as much electricity as the average American home, at 1600 square feet.
—Dave Levitan, “How Big is the U.S. 'Electricity Gap'?,” IEEE Spectrum, March 08, 2013
1998 (earliest)
Off-grid renewable energy systems represent an important option for narrowing the electricity gap in rural parts of the developing world.
—John Byrne, et al., “The economics of sustainable energy for rural development: A study of renewable energy in rural China” (PDF), Energy Policy, Volume 26, Number 1, January 02, 1998
A second sense of this phrase — the gap between electricity supply and demand, particularly when the demand exceeds supply — is quite a bit older, dating to at least the late 1960s.