Renewable energy is theĀ  energy that comes from resources which are naturally replenished on a human timescale, such as sunlight , wind , rain ,
tides, waves , and geothermal heat. Renewable energy replaces conventional fuels in four distinct areas: electricity generation , air and water heating/cooling, motor fuels , and rural energy services.

Renewable energy resources are always available to be tapped, and will not run out.
Renewable energy includes Biomass, Wind, Hydro-power, Geothermal and Solar sources .

SOLAR ENERGY: This form of energy relies on the nuclear fusion power from the core of the Sun. This energy can be collected and converted in a few different ways. The range is from solar water heating with solar collectors or attic cooling with solar attic fans for domestic use to the complex technologies of direct conversion of sunlight to electrical energy using mirrors and boilers or photovoltaic cells. Unfortunately these are currently insufficient to fully power our modern society.
WIND POWER: The movement of the atmosphere is driven by differences of temperature at the Earth’s surface due to varying temperatures of the Earth’s surface when lit by sunlight. Wind energy can be used to pump water or generate electricity, but requires extensive areal coverage to produce significant amounts of energy.
HYDROELECTRIC ENERGY : This form uses the gravitational potential of elevated water that was lifted from the oceans by sunlight. It is not strictly speaking renewable since all reservoirs eventually fill up and require very expensive excavation to become useful again. At this time, most of the available locations for hydroelectric dams are already used in the developed world.
BIOMASS : Biomass is the term for energy from plants. Energy in this form is very commonly used throughout the world. Unfortunately the most popular is the burning of trees for cooking and warmth. This process releases copious amounts of carbon dioxide gases into the atmosphere and is a major contributor to unhealthy air in many areas. Some of the more modern forms of biomass energy are methane generation and production of alcohol for automobile fuel and fueling electric power plants.

The Penalty for Ignorance is Lack