Simple: Too expensive, not effective enough to meet the demand of the population, or the country is not ready to transition to clean/renewable energy.
When it comes to energy production, one things comes to mind, "How much money can this make me and how much will it cost to make it?" The moral focus for saving the world is never a prominent drive in the race to save the Earth, but that is changing. Slowly, of course.
After all, the ENTIRE world revolves around money. Money makes the world go round.