In this, an overview of the 5 most promising up and coming renewable energy sources are discussed. Within each of these 5 emerging sustainable technologies there are sub-technologies which still need developing that may not be mentioned. Some are closer than others to commercialization, but the progress rate for these technologies is faster than ever.
Marine energy is one of the more attractive renewable energy sources because of the fact that oceans cover three-quarters of the Earth’s surface. Several techniques have been practiced or tested for extracting energy from the ocean and are as follows:
Wave power is the transport of energy by ocean surface waves and the harnessing of that energy to produce useful work such as electricity generation and seawater desalination. There are a few different ways to accomplish this, but one method channels and focuses waves along a shoreline into a basin where the water flows to a turbine at a lower elevation. Methods to strengthen the force of the waves are being explored in order to spin turbines at a higher rate.
Tidal power is the only technology that draws energy inherent in the orbital characteristics of the earth-moon system. It works similar to reservoir power plants except water doesn’t flow downhill, but back and forth.
Salinity Gradient Solar Pond
A salinity gradient solar pond is an integral device for collecting and storing solar energy. In an ordinary pond or lake, when the sun’s rays heat up the water, the heated water being lighter, rises to the surface and loses its heat to the atmosphere. The net result is that the pond water remains at nearly atmospheric temperature. Solar pond technology inhibits this phenomenon by dissolving salt into the bottom layer of this pond, making it too heavy to rise to the surface, even when hot. The salt concentration increases with depth, thereby forming a salinity gradient. The sunlight that reaches the bottom of the pond is trapped there and the useful thermal energy is then withdrawn from the solar pond in the form of hot brine.
When the sun’s rays fall on the oceans, thermal energy is absorbed and stored in the upper layer. The energy is extracted by making use of the Ocean Energy Thermal Cycle (OTEC) cycle. OTEC cycles use the temperature difference between the warm seawater at the surface and cold seawater, at depths of about 900m, to produce electricity. Warm seawater is used to produce vapors (working fluid for driving a turbine) while cold water is used to condense the vapors and regulate the vapor pressure difference to drive the turbine.
Concentrated Solar Power (CSP)
Concentrated solar power is the technology used for generating electricity using heat produced by solar irradiation, by concentrating it on a small area. CSP makes use of mirrors or lenses to reflect sunlight into a receiver where a primary circuit collects the heat where it is either used directly or via a secondary circuit to generate electricity by utilizing a turbine.
CSP is considered the most mature renewable energy technology and gives the lowest risk in terms of development but it requires a lot of
Enhanced Geothermal Energy System (EGS)
Geothermal Energy is the form of thermal energy stored in the Earth’s crust. The temperature difference between the core of the Earth and its surface is known as geothermal gradient, and it drives a continuous conduction of thermal energy from the core to the surface. The potential of geothermal is on par with other mainstream renewable energy sources.
Considered one of the few renewable energy technologies that can be employed as the base load, power generating source, EGS depends on specially engineered reservoirs to extract geothermal energy, instead of relying on natural reservoirs. This allows for an extended lifetime, increased productivity, siting flexibility, expanded resources, sizing flexibility, and environmental benefits.
Some drawbacks may come with enhanced geothermal technologies including increased seismic activity and/or landslides, and air and water quality, especially if plants are not properly designed or maintained. Despite these concerns, EGS has a huge potential to lessen carbon emissions and is sustainable.
Cellulosic Ethanol (Biofuels)
Cellulosic Ethanol belongs to the alcohol family and can be produced from a variety of plant material as feedstock, which is used as liquid fuel. Typically ethanol is made from sugarcane or cornstarch, but emerging technologies are coming up with ways to use wood, grass, other inedible parts or remnants of plants, municipal waste, and algae. It has been estimated by researchers at the University of California at Berkeley that cellulosic ethanol has the potential of lowering greenhouse gas emission by 90%.
There is virtually no
The major challenges facing the cellulosic ethanol field are either in the formation of commercial level plants or are related to technical aspects of the process such as improving enzyme efficiency and production costs, development of more robust fermenting organisms, and reducing the number of steps in cellulosic ethanol formation. Cellulosic Ethanol is also more corrosive and tends to absorb moisture from the air, making it more difficult to ship. In addition, motors would need to be modified as it is incompatible with most of the components of existing engines.
Artificial Photosynthesis/Hydrogen Power (AP)
Hydrogen produces power without carbon emissions and is the only renewable fuel source that doesn’t produce a single pollutant. It may be the world’s most significant new power source. Hydrogen fuel cells produce an electric current that can be directed to do work such as power an engine or entire city. No greenhouse gas emissions are created through nuclear power, but as of 2010, the world’s uranium reserves would only last approximately 56 years longer.
Artificial photosynthesis is the process of deriving energy (hydrogen) from sunlight and water through a process called water splitting. AP offers a two-fold benefit as it provides energy and releases oxygen back into the atmosphere. There are 3 basic steps for photosynthetic water splitting. The first step is light harvesting through chlorophyll molecules. Second is the transportation of electrons, mediated by tyrosine, which also acts as
Artificial photosynthesis is a promising renewable energy source for the future but
As of 2017, the combined global contribution of renewable energy sources was about 25%, reports say that now energy consumption at a global level is higher than ever. The
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