After a five-year wait, Lorraine Black and Ricky Gillis heard the rumblings of an electrical crew reach their home on the sprawling Navajo Nation.

In five days’ time, their home would be connected to the power grid, replacing their reliance on a few solar panels and propane lanterns. No longer would the CPAP machine Gillis uses for sleep apnea or his home heart monitor transmitting information to doctors 400 miles away face interruptions due to intermittent power. It also means Black and Gillis can now use more than a few appliances — such as a fridge, a TV, and an evaporative cooling unit — at the same time.

Many Navajo families still live without running water and electricity, a product of historic neglect and the struggle to get services to far-flung homes on the 27,000-square-mile (70,000-square-kilometer) Native American reservation that lies in parts of Arizona, New Mexico and Utah. Some rely on solar panels or generators, which can be patchy, and others have no electricity whatsoever.