Role of renewable energy sources in environmental protection: A review

Abstract

Renewable technologies are considered as clean sources of energy and optimal use of these resources minimize environmental impacts, produce minimum secondary wastes and are sustainable based on current and future economic and social societal needs. Sun is the source of all energies. The primary forms of solar energy are heat and light. Sunlight and heat are transformed and absorbed by the environment in a multitude of ways. Some of these transformations result in renewable energy flows such as biomass and wind energy. Renewable energy technologies provide an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting conventional energy sources. In this article a review has been done on scope of CO₂ mitigation through solar cooker, water heater, dryer, biofuel, improved cookstoves and by hydrogen.

Introduction

Renewable energy sources (RES) supply 14% of the total world energy demand [1]. RES includes biomass, hydropower, geothermal, solar, wind and marine energies. The renewable are the primary, domestic and clean or inexhaustible energy resources [2], [3]. Large-scale hydropower supplies 20 percent of global electricity. Wind power in coastal and other windy regions is promising source of energy [1], [4]. Main renewable energy sources and their usage forms are given in Table 1. RESs are also called alternative energy sources. The share of RESs is expected to increase very significantly (30–80% in 2100) [4]. The global renewable energy scenario by 2040 is presented in Table 2.

Sustainable development requires methods and tools to measure and compare the environmental impacts of human activities for various products [7]. At present, consumption of fossil fuels is dramatically increasing along with improvements in the quality of life, industrialization of developing nations, and increase of the world population. It has long been recognized that this excessive fossil fuel consumption not only leads to an increase in the rate of diminishing fossil fuel reserves, but it also has a significant adverse impact on the environment, resulting in increased health risks and the threat of global climate change [8]. Changes towards environmental improvements are becoming more politically acceptable globally, especially in developed countries. Society is slowly moving towards seeking more sustainable production methods, waste minimization, reduced air pollution from vehicles, distributed energy generation, conservation of native forests, and reduction of greenhouse gas emissions [9].

Increasing consumption of fossil fuel to meet out current energy demands alarm over the energy crisis has generated a resurgence of interest in promoting renewable alternatives to meet the developing world's growing energy needs [10], [11]. Excessive use of fossil fuels has caused global warming by carbon dioxide; therefore, renewable promotion of clean energy is eagerly required [12]. To monitor emission of these greenhouse emissions an agreement was made with the overall pollution prevention targets, the objectives of the Kyoto Protocol agreement [13]. In this paper, attempt has been made to find out the scope of renewable energy gadgets to meet out energy needs and mitigation potential of greenhouse gases mainly carbon dioxide.