Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human scale, such as sunlight, wind, rain, tides, waves and geothermal heat.  Renewable energy often provides energy in four important areas: power generation, air and water heating and cooling, rural transportation and energy services (off grid) . 
Based on REN21’s 2016 report, renewable energies contributed 19.2% of global human energy consumption and 23.7% of their electricity generation in 2014 and 2015, respectively. This energy consumption is divided into 8.9% from traditional biomass, 4.2% from thermal energy (modern biomass, geothermal and solar heat), 3.9% from hydropower and 2.2% from electricity. wind, solar, geothermal and biomass. Global investments in renewable technologies reached more than US $ 286 billion in 2015, with countries like China and the United States investing heavily in wind, hydro, solar and biofuels. Globally, an estimated 7.7 million jobs are associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer.  In 2015 worldwide, more than half of all new installed electricity capacity was renewable. 
Renewable energy resources exist over large geographic areas, unlike other energy sources that are concentrated in a limited number of countries. The rapid deployment of renewable energy and energy efficiency translates into significant energy security, climate change mitigation and economic benefits.  The results of a recent review of the literature  conclude that as greenhouse gas emitters begin to be held accountable for the damage resulting from GHG emissions resulting in climate change, high value for mitigation of liabilities for the deployment of renewable energy technologies. In international public opinion surveys there is strong support for the promotion of renewable sources such as solar energy and wind energy.  At the national level, at least 30 countries around the world already have renewable energy contributing more than 20% of the energy supply. National renewable energy markets are expected to continue to grow strongly in the next decade and beyond.  Some locations and at least two countries, Iceland and Norway, are already producing all their electricity using renewable energy, and many other countries have set themselves the target of achieving 100% renewable energy in the future. For example, in Denmark, the government has decided to change the total energy supply (electricity, mobility and heating / cooling) to 100% renewable energy by 2050. 
While many renewable energy projects are large-scale, renewable technologies are also suitable for rural and remote areas and developing countries, where energy is often crucial for human development.  Former UN Secretary-General Ban Ki-moon said that renewable energy has the capacity to bring the poorest countries to new levels of prosperity.  As most renewables provide electricity, the deployment of renewable energy is often applied in conjunction with further electrification, which has several advantages: Electricity can be converted into heat (if necessary generate higher temperatures). higher than fossil fuels), can be converted into mechanical energy with high efficiency and is clean at the point of consumption.   In addition to this electrification with renewable energy is much more efficient and therefore leads to a significant reduction in primary energy requirements, because most renewable energies do not have a steam cycle with high losses of 40 to 65%). 
Renewable energy systems are rapidly becoming more efficient and less expensive. Their share in total energy consumption is increasing. Growth in coal and oil consumption could be completed by 2020 due to increased use of renewable energy and natural gas.