Renewable energy is energy from renewable natural resources that are replenished on a human timescale. Using renewable energy technologies helps with climate change mitigation, energy security, and also has some economic benefits. Commonly used renewable energy types include solar energy, wind power, hydropower, bioenergy and geothermal power. Renewable energy installations can be large or small. They are suited for urban as well as rural areas. Renewable energy is often deployed together with further electrification. This has several benefits: electricity can move heat and vehicles efficiently, and is clean at the point of consumption. Variable renewable energy sources are those that have a fluctuating nature, such as wind power and solar power. In contrast, controllable renewable energy sources include dammed hydroelectricity, bioenergy, or geothermal power.
A small, roof-top mounted PV system in Bonn, Germany
Komekurayama photovoltaic power station in Kofu, Japan
Burbo, NW-England
Sunrise at the Fenton Wind Farm in Minnesota, United States
In physics, energy is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light. Energy is a conserved quantity—the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J).
A plasma globe, using electrical energy to create plasma, light, heat, movement and a faint sound
In a typical lightning strike, 500 megajoules of electric potential energy is converted into the same amount of energy in other forms, mostly light energy, sound energy and thermal energy.
Thermal energy is energy of microscopic constituents of matter, which may include both kinetic and potential energy.
Thomas Young, the first person to use the term "energy" in the modern sense