Energy

7Renewable Energy: Sources, Importance and Prospects for Sustainable Future

Shachi Agrawal and Renu Soni

Department of Botany, Gargi College, University of Delhi, New Delhi, India

7.1 Introduction

Past few decades have experienced exponential increase in use of energy all over the world from 8588.9 million tonnes (in 1995) to 13 147.3 million tonnes (in 2015) (Dong et al. 2020). The energy demand in India is also increasing very drastically, and it is predicted that by 2030 the whole energy demand of India may be more than twofold and electricity demand will be almost threefold than that of existing value (IRENA 2017). This global energy demand is to be fulfilled from various sources which can be mostly divided into two classes – the traditional non‐renewable and modern renewable sources. As the name suggests, non‐renewable sources cannot be replenished and get exhausted, whereas renewable resources are regenerative in some form or the other and do not deplete over time. Non‐renewable resources, majorly fossil fuels, take millions of years to form. As per the World Energy Forum, at the current consumption level across the world, coal, fossil‐based oil and gas reserves can last another century as they account for almost 80% of the primary energy consumed at the current global level (Zerta et al. 2008; Zhang et al. 2017; Jamshidi and Askarzadeh 2019; Ahmad and Zhang 2020). In addition, usage of non‐renewable resources negatively affects the carbon balance of the earth's ecosystem ...