Complex sentence: Kosovo's annual per capita GDP of 2,600 EUR makes it one of Europe's poorest countries and one of the mayor obstacles for the economic growth and development is inadequate and unreliable electricity supply.
Split into simpler sentences: Kosovo's annual per capita GDP of 2,600 EUR makes it one of Europe's poorest countries. A mayor obstacle for the economic growth and development of Kosovo is the inadequate and unreliable electricity supply.