Renewables; Perspective and Challenges
Over recent decades, significant changes have transpired the energy sector. High energy costs, destructive impacts on the environment and one-time efficiency are among the most important issues which have driven many countries to shift from fossil energies to new sources of energy.
Using renewable energies like water, wind and solar heating are among important sectors which different countries focus upon. Therefore, it would be important to study the perspective and challenges of using renewable energies in different countries.
Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources. Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services.
The mainstream technologies used for extracting renewable energies are as follows:
Wind Power: Airflows can be used to run wind turbines. Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand, assuming all practical barriers needed were overcome.
Hydropower: It is used mainly in hydroelectricity.
Solar Energy: Solar energy, radiant light and heat from the sun, is harnessed using a range of ever-evolving technologies. In 2011, the International Energy Agency said that the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. In 2016, after another year of rapid growth, solar generated 1.3% of global power.
Geothermal Energy: High Temperature Geothermal energy is from thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals.
Bioenergy: Biomass is biological material derived from living, or recently living organisms. It most often refers to plants or plant-derived materials which are specifically called lignocellulosic biomass. As an energy source, biomass can either be used directly via combustion to produce heat, or indirectly after converting it to various forms of biofuel. Conversion of biomass to biofuel can be achieved by different methods which are broadly classified into: thermal, chemical, and biochemical methods. Wood remains the largest biomass energy source today; examples include forest residues – such as dead trees, branches and tree stumps –, yard clippings, wood chips and even municipal solid waste.
Atomic Energy: Atomic energy is one of the most well-known forms of renewable energy, whose technology is monopolized by a few countries. Nuclear energy power plants are able to generate electricity on a large scale and they are considered as a source of clean energy. Nonetheless, there are many challenges with the use of this energy because acquiring this technology may lead to the development of atomic bombs.
Energy Storage: Energy storage is a collection of methods used to store electrical energy on an electrical power grid, or off it. Electrical energy is stored during times when production (especially from intermittent power plants such as renewable electricity sources such as wind power, tidal power, solar power) exceeds consumption, and returned to the grid when production falls below consumption.
Perspective and Challenges
In recent years, significant investment has been made in renewable energies. For instance, this investment has increased from 182 points in 2008 to 241 points in 2016. Moreover, the number of countries using renewable energies increased from 79 in