Short answers, pulled from the story.
In 2024-86% of the world's energy needs were met from fossil fuels, up from 81% in 2005. Fossil fuels include coal, petroleum, and natural gas, and remain the dominant primary energy source globally.
Nuclear power plants, excluding naval reactors, provided about 5.7% of the world's energy and 13% of the world's electricity in 2012. As of 2013, the International Atomic Energy Agency counted 437 operational reactors in 31 countries.
The 2011 Fukushima Daiichi nuclear disaster, which displaced 50,000 households after radioactive material leaked into air, soil, and sea, prompted a rethink of nuclear safety in many countries. Germany decided to close all its reactors by 2022, Italy banned nuclear power, and the International Energy Agency halved its estimate of additional nuclear capacity to be built by 2035.
Hydropower generated 16.6% of the world's total electricity and 70% of all renewable electricity in 2015. China was the largest producer, generating 721 terawatt-hours in 2010, representing around 17% of its domestic electricity use.
The International Energy Agency estimated that improved energy efficiency in buildings, industrial processes, and transportation could reduce global energy demand in 2050 to around 8% smaller than today's level, while serving an economy more than twice as large. Compact fluorescent lights use two-thirds less energy than incandescent bulbs and may last 6 to 10 times longer, illustrating how efficiency gains reduce overall demand.
The Drake Landing Solar Community is located in Alberta, Canada, and uses borehole thermal energy storage to obtain 97% of its year-round heat from solar collectors on garage roofs, with most of the heat collected during summer. It demonstrates how interseasonal thermal storage can make renewable solar energy available through colder months.