Renewable Energy

The current world faces dual challenges to satisfy the growing energy demand and to reduce greenhouse gas emissions while improving energy efficiency. Renewable Energy is an effective way to cope with this dilemma, using energy as efficiently as possible to reduce greenhouse gas emission. Renewable energy can be divided into six categories as follows: (1) Solar energy from sunlight, (2) Wind energy from wind, (3) Hydropower from water, (4) Bioenergy from plants, (5) Geothermal energy from the earth’s internal heat, and (6) Ocean energy from ocean’s waves. Since the net-Zero pledge is the renewable energy policy drivers, the Net-Zero policies announced by the developed nations such as United States, United Kingdom, Germany, and Japan were addressed. Both principles and applications of renewable energy were illustrated. Renewable energy services included renewable energy (RE) industry, smart grid, and energy services company (ESCO) were also presented. In general, common barriers hamper implementation including uncompetitive costs, the need for efficient, cheap, environmentally sound energy conversion technologies, public acceptability, ecological aspects, and competition for land use and so on. Therefore, specific measures such as developing of new alternative/renewables, enhancing energy management through digital/mobile robotic automated technologies, providing incentives i.e., Feed-In-Tarif (FIT) for renewable energies, and promoting market-oriented new regulations should be developed and implemented to optimize the renewable energy system.