A majority of the countries in the world now engage in some form of government intervention within the renewable energy sector, with the numbers consistently growing year on year. By 2018, 146 countries had renewable power targets, 138 countries had support policies directed at renewable energy and 113 countries had national renewable energy laws in force. In this context, it is important to understand the economic rationale for intervening in the renewable energy sector, as well as the factors driving this growth in the development of national renewable energy laws.