The problem: large sections of the world are without access to the grid. In many countries, people rely on kerosene lamps to light their homes. The kerosene is expensive, costing a huge fraction
of some family budgets, and somewhat dangerous-- it can cause burns and fires, and constantly inhaling the smoke can cause respiratory problems.
There are a number of entrepreneurs and large businesses seeking solutions to this problem. I'm going to single out Lighting Africa
because their goal is to help establish the market for off grid energy solutions (dealing with regulatory issues in country, market intelligence, etc), without selecting one technology to be "the" solution. Competition and quality will sort out the winners from the losers here, in time.
The two big technologies for producing lighting off grid in this context were solar
powered solutions. They all rely on LED technology to get the most light for the smallest amount of electricity, but are ultimately powered either by the sun during the day, or by muscle power.