Renewable energy is usable energy derived from renewable sources such as sun, wind, rivers, geothermal. The sun is our most powerful source of energy. Sunlight, or solar energy, can be used to heat, light, and cool homes and other buildings, generate electricity, heat water, and more. More than a million euros worldwide are expected to be invested this year in technologies such as wind power, solar power, electric vehicles and batteries, according to the IEA. Alternative energy sources. As fossil fuel reserves are expected to become less available, more expensive, and of increasing environmental concern over the coming century, energy dependence will increase. Background information. Vocabulary. In any debate about climate change, renewable energy usually tops the list of changes the world can implement to stave off the worst effects of rising temperatures. This is because renewable energy sources, such as solar and wind, do not emit carbon dioxide or other greenhouse gases that contribute to the transition to a renewable energy system, according to another Finnish study. If the country is known for its oil deposits, it is also rich in another source of energy: the sun to power solar energy. solar power could meet the country's energy demand, supported by an improved battery and,