Renewable energy is obtained from sources that are practically unlimited in quantity and/or have a very short regeneration period. Examples of renewable energy sources are Sun, water, wind, etc. For example, Sun has practically unlimited quantity of energy that we can use and we get sunlight every day. Similarly, we can use wind's energy and still get new wind afterwards. Similar is the case with water, we can make electricity from it again and again, by dropping it from a height. In comparison, non-renewable energy is generated from sources that are limited in quantity and takes a long time to regenerate. For example, coal is a non-renewable energy source and is available in finute quantity. Since it takes millions of years to form, once we run out of all coal reserves, we will have to wait for that many years to get fresh coal. Another major difference between the two is that the non-renewable energy sources are generally associated with gas emissions and global warming. In comparison, renewable energy sources are cleaner and do not generate gases during operation.
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