Osmotic power — power production based on the osmotic pressure difference between waters with varying salt gradients

Osmotic power is a new renewable energy, which is stands out as a promising and unexploited sources. It uses a membrane as a filtrer that will let water flow through, while it catches suspended solids and other substances, this is the membrane technology. This is the main technology for an efficient osmotic power production. 

The principle of the osmosis is to place a semi-permeable between two tanks containing water with different salt gradients. By the use of the entropy of mixing water, and the creation of increasing pressure due to osmotic forces, we would be able to see a laminar flow of water to the most saltier side. This increased pressure is introduced into a turbine to create the energy. 

The osmotic power is capable to produce approx 12 TWh/year, and to operate during 7000 hours a year at full capacity (while a wind mill is designed to operate in a average 3.500 hours a year at various capacities). 

Osmotic power represents an existing new renewable energy source with a strong commercial potential. However, this technology is expensive to settle, but the rentability is more significant. 

Photovoltaic solar energy: Conceptual framework

The solar energy is developed in this article in 4 steps: introduction, research method, photovoltaic solar energy, and conclusion. 

Virtually all photovoltaic devices incorporate a PN junction in a semiconductor, which through a photo voltage is developed. These devices are also known as solar cells or photovoltaic cells. A typical solar cell is shown in picture below. The PN junction is the main part of the cell where the light receiving portion is the N-type material in the part below this the material is P-type. 

 

Despite the decrease in generation during cloudy days, energy from the sun is abundant, while the volume of water in the dams during periods of drought is limited. If compared to wind energy, photovoltaic solar energy is silent and can be generated in urban areas since panels can be installed on the roof. 

Thus, we can adopt as a concept of photovoltaic solar energy the following definition: electricity obtained directly from the conversion of solar energy. 

Advantages 

• Reliable systems 

• Low cost of operation and maintenance 
• Low maintenance 
• Free energy source 
• Clean Energy 
• High Availability 

• The generation can be made closer to the consumer 
• Does not cause environmental impacts 
• Potential to mitigate emissions of greenhouse gasses 
• Noiseless 

Disadvantages 

• High initial cost 
• Needs a relatively large area of installation 
• High dependence on technology development 
• Geographical conditions (solar irradiation) 

Silicon is the most popular material in commercial solar cell modules, accounting for about 90% of the photovoltaic cell market 

It’s generally stable and non-toxic, bandgap of 1.12 eV, almost ideally adapted to the terrestrial solar spectrum, that is, the silicon is sensitized within the range of electromagnetic spectrum emitted by the sun. 

Currently PV plant suppliers cite an operating lifetime of a 30 year PV installation, but the warranty for the material is usually limited to 5 years due to damaging events such as damage from improper installation or maintenance, hail, Snow and storm, etc. In Europe, modules that have failed during transportation, installation or operation are collected for disposal by the European Association PV CYCLE. Across Europe, by the end of December 2015, 13,239 t of failed or depleted modules have been collected.  

Link to the article 

http://www.sciencedirect.com/science/article/pii/S1364032117303076#s0085