Renewable energy systems: Comparisons, challenges and barriers, sustainability indicators, and the contribution to UN sustainable development goals

Because of the harsh environmental impacts of fossil fuels, price fluctuation, and resource limitation, renewable energy resources (RERs) are considered the ultimate solution to overcome these challenges. RERs are also abundant and environmentally friendly. It has been reported that the growth rates in renewable energy installations have increased by 8–9% annually since 2010, reaching a cumulative capacity of 2.9 TW by 2020 and exceeding the growth rate for fossil resources. In this work, the different RERs have been critically discussed in terms of their operation principles, advantages, disadvantages, and associated environmental impacts, focusing on wind and solar energies as the most deployed RERs. Barriers to the full deployment of RERs to replace fossil resources are discussed. Based on the discussion presented on RERs, the contribution of deploying RERs towards the achievement of the United Nations (UN) Sustainable Development Goals (SDGs) is also critically discussed. A total of 80 indicators have been identified for RERs' contribution toward the achievement of SDGs.