Megha BR

Hi, I am Megha B R, I have completed my Post-Graduation in Solid State Physics and pursuing B. Ed. I am a Physics enthusiast. As an Academic writer, my goal is to reach the readers in a simplified manner through my articles. Let's connect through LinkedIn-

Comprehensive Guide to the Types of Solar Energy Technologies

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types of solar energy

Solar energy is a rapidly growing and increasingly important source of renewable energy, with two primary technologies leading the way: Photovoltaic (PV) systems and Concentrating Solar Power (CSP) systems. This comprehensive guide delves into the technical details, physics principles, and practical applications of these two solar energy technologies, providing a valuable resource for physics students and enthusiasts alike.

Photovoltaic (PV) Systems

Photovoltaic (PV) systems are the most widely deployed solar energy technology, converting sunlight directly into electricity using semiconductor materials, such as silicon. The underlying physics behind PV systems is the photovoltaic effect, where the absorption of photons in the semiconductor material generates electron-hole pairs, which are then separated and collected to produce an electric current.

Photovoltaic Effect

The photovoltaic effect is the fundamental principle that drives PV systems. When photons from sunlight are absorbed by the semiconductor material in a PV cell, they excite electrons in the material, causing them to break free from their atoms and creating electron-hole pairs. These charge carriers are then separated by the built-in electric field in the PV cell, generating a flow of electric current.

The efficiency of the photovoltaic effect is determined by the bandgap energy of the semiconductor material, which represents the energy required to excite an electron from the valence band to the conduction band. The bandgap energy of silicon, the most commonly used semiconductor in PV cells, is 1.12 eV, which corresponds to a wavelength of approximately 1100 nm in the near-infrared region of the electromagnetic spectrum.

PV Cell Design and Efficiency

PV cells are typically made of thin wafers of semiconductor materials, with the most common being crystalline silicon (c-Si) and thin-film technologies, such as amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium selenide (CIGS). The design of PV cells aims to maximize the collection and separation of the electron-hole pairs generated by the photovoltaic effect, as well as to minimize energy losses due to recombination and resistance.

The efficiency of PV cells in converting sunlight into electricity varies, with typical commercial modules having efficiencies ranging from 15% to 22%. The efficiency of PV systems is influenced by factors such as the semiconductor material, cell design, module configuration, and environmental conditions, such as temperature and irradiance.

PV System Components and Configuration

A complete PV system consists of several key components, including:

  1. PV modules: These are the primary energy-generating units, made up of interconnected PV cells.
  2. Inverters: These devices convert the direct current (DC) generated by the PV modules into alternating current (AC) that can be used by the electrical grid or local loads.
  3. Mounting structures: These support the PV modules and orient them towards the sun to maximize energy production.
  4. Balance of system (BOS) components: These include wiring, combiner boxes, disconnects, and other electrical components necessary for the proper functioning of the PV system.

PV systems can be configured in various ways, such as grid-connected systems, off-grid systems, and hybrid systems that combine PV with other energy sources, such as batteries or diesel generators.

PV System Performance and Capacity Value

The performance of PV systems is typically measured in terms of their capacity value, which represents the level of reliability they can provide to the electrical grid. The capacity value of PV plants can range from 50% to 80% of their AC rating, with the higher values representing systems that use active tracking to orient the PV modules towards the sun.

Active tracking systems, which use motors to continuously adjust the orientation of the PV modules, can significantly improve the energy output and capacity value of PV systems. However, these systems also come with additional complexity, maintenance requirements, and energy consumption, which must be weighed against the potential benefits.

Concentrating Solar Power (CSP) Systems

types of solar energy

Concentrating Solar Power (CSP) systems, also known as solar thermal power plants, use mirrors or lenses to concentrate a large area of sunlight onto a small area, generating heat that is then converted into electricity. This approach differs from PV systems, which directly convert sunlight into electricity.

CSP System Components and Technologies

CSP systems typically consist of the following key components:

  1. Solar collectors: These are the mirrors or lenses that concentrate the sunlight onto a receiver.
  2. Receivers: These absorb the concentrated solar radiation and convert it into thermal energy.
  3. Heat transfer fluid: This fluid, such as molten salt or synthetic oil, carries the thermal energy from the receiver to the power block.
  4. Power block: This is where the thermal energy is converted into electricity, typically using a steam turbine or Stirling engine.
  5. Thermal energy storage: Some CSP systems include thermal energy storage, allowing them to generate electricity even when the sun is not shining.

There are several different CSP technologies, including:

  1. Parabolic trough: Curved, trough-shaped mirrors focus sunlight onto a receiver tube running along the focal line of the trough.
  2. Solar power tower: A field of mirrors (heliostats) focuses sunlight onto a receiver at the top of a central tower.
  3. Parabolic dish: Dish-shaped mirrors concentrate sunlight onto a receiver located at the focal point of the dish.
  4. Linear Fresnel reflector: Flat or slightly curved mirrors focus sunlight onto a linear receiver.

CSP System Efficiency and Capacity Value

The efficiency of CSP systems in converting solar energy into electricity varies, depending on the specific technology and design. Typical commercial CSP plants have efficiencies in the range of 15% to 25%.

The capacity value of CSP plants without storage can be similar to that of PV plants, meaning that a 100-MW (AC rated) CSP plant can potentially provide the same level of reliability as a 50-MW to 80-MW conventional plant, depending on the type and location of the CSP system.

However, CSP systems with thermal energy storage can have significantly higher capacity values, as they can generate electricity even when the sun is not shining. This storage capability allows CSP plants to provide a more reliable and dispatchable source of electricity, making them an attractive option for grid integration.

Land Use and Environmental Impacts

The land use and environmental impacts of solar energy systems, including both PV and CSP, are important considerations. A study on standardized metrics to quantify solar energy-land relationships found that the land-use intensity of electricity production varies widely across different solar energy technologies and land-use contexts.

For example, the land-use intensity of utility-scale PV systems can range from 0.3 to 2.8 acres per megawatt-hour (MWh) of annual electricity generation, while the land-use intensity of CSP systems can range from 1.4 to 4.5 acres per MWh. These variations are influenced by factors such as the specific technology, solar resource quality, and local land-use characteristics.

It is important to consider the full life cycle of solar energy systems, including the production, installation, operation, and decommissioning phases, when evaluating their land-use impacts. A systematic literature review identified 80 articles that addressed land-related properties of PV and CSP solar energy generation technologies, underscoring the importance of this topic.

Conclusion

Photovoltaic (PV) and Concentrating Solar Power (CSP) systems are the two primary types of solar energy technologies, each with its own unique characteristics and applications. PV systems directly convert sunlight into electricity using semiconductor materials, while CSP systems use mirrors or lenses to concentrate sunlight and generate heat that is then converted into electricity.

Both PV and CSP systems have their own advantages and challenges, and the choice between them depends on factors such as the available solar resource, land use constraints, and the specific energy needs of the application. As the solar energy industry continues to evolve, a deeper understanding of the technical details, physics principles, and practical considerations of these technologies will be crucial for advancing the field and meeting the growing demand for renewable energy.

References:

  1. National Renewable Energy Laboratory. “Best Practices Handbook for the Collection and Use of Solar Energy Systems Data.” NREL, 2018.
  2. Frontiers in Sustainability. “Standardized metrics to quantify solar energy-land relationships.” Frontiers, 2022.
  3. Office of Energy Efficiency and Renewable Energy. “Solar Energy and Capacity Value.” NREL, 2013.
  4. Sun Yanwei, Li Ying Wang, Run Ma, and Renfeng. “Measuring dynamics of solar energy resource quality: Methodology and policy implications for reducing regional energy inequality.” ScienceDirect, 2022.

13+ Ocean Pressure Example: Detailed Facts

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Ocean pressure is defined as “pressure in the ocean, which is a result of the weight of the water column pressing down on an object due to gravity”.

In general, the ocean pressure can also be stated as “the weight of the water above pushes on any object below it”.

Detailed explanation of ocean pressure example

In this section, you will learn detailed explanation of above mentioned ocean pressure examples

Ocean pressure in ocean circulation

Ocean circulation is the wide-ranging sheath movement of water in the ocean basins. Ocean circulation is a result of wind pushing which involves pressure on the surface of the water and density difference between the water. Density is a very important property of an ocean because small local changes in density result in local variations in pressure at a given depth, which results in a driving of ocean circulation.

ocean pressure example
Ocean pressure in ocean circulation
image credit: snappygoat

Ocean pressure in Human Body

The human body is one of the most censurable things on the planet. But despite human bodies’ many abilities, human bodies are pretty delicate when we consider the universe around us. For example, we have our pressure in air-filled spaces of our body like our lungs, stomach, and ears our internal pressure is equal to the outside air pressure. But when we jump into the ocean, we feel uncomfortable because our internal pressure is no longer equal to the ambient pressure. This is the reason for our ears hurt when we dive into the ocean.

High pressure in the depth of ocean

Everything in the deep ocean is under a huge estimate of pressure at any depth in the ocean, with all feet an object descends into the ocean more pressure is exerted upon that object hence more water is pushing down and against it. Because of this high pressure in the depth of the ocean scientist and explorers use specially designed equipment like remotely operated vehicles and manned submersibles that can effectuate under extreme pressure.

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High pressure in ocean depth image credit: pixabay

Pressure of ocean depth in human body

The one reason the human body could not withstand the pressure of the ocean depth without preservation is the variation in volume between pressurized air and pressurized water. When the human body is at a deep enough level, water pressure increases, and the volume of air in the human body decreases because the human body does not have the strength to push back against the water pressure hence the lungs would collapse completely and causes ruptured eardrum and also cause breathing problem and killing instantly.

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Pressure of ocean depth in human body
image credit: pixabay

Pressure at ocean level

The ocean can vary up to 100m from a uniform ellipsoid depending on the density of the earth under it, the continent on which it sits changes the level of the ocean. The gravitational attraction of land pulls more water because of pressure raising the ocean around it.

 Ocean pressure is low near the equator and is called equatorial law if the pressure near the poles is high and is called polar high. The water content at the ocean level is at normal temperature pressure is 1013.25millibars.

Ocean pressure in living things

A band of ocean cade has lung-like swim bladders which help in controlling their buoyancy. The influence of ocean depth is less for organisms without swim bladders which don’t collapse because in the ocean the pressure outside the water is equivalent to the gas inside so they are less affected by pressure than we imagine. Ocean pressure affects the chemical reaction, and organisms adapted to this pressure may experience a metabolic problem. Fish can breathe without using lungs so the pressure difference remains balanced.

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Ocean pressure in living things image credit: pixabay

Water pressure in ocean

It is the force that pushes water through pipes. The pressure increases by about 1atm for every 10m of water depth. The water pressure in the ocean is 3000 to 9000 pounds per square inch. Water pressure is so high in the ocean because the weight of the water above pushes on any object below it. if the more water is pushing down and against it and more pressure is exerted upon that object.

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Water pressure in ocean image credit: pixabay

Atmospheric pressure in ocean

Atmospheric pressure has a direct impact on the ocean level when we wigwag from ocean level to a heave on land, atmospheric pressure drops this is because of less air above we pressing down. For every 10.06m, we go down the pressure increases by 1atm. The force on the surroundings exerted by the high air pressure results in water movement, so in ocean areas high atmospheric pressure low ocean level, and vice-versa.

Pressure near or above ocean level

At ocean level, if the altitude increases the gas molecules decrease leading to a decrease in atmospheric pressure for example when a person or any other marine creature swims, water presses against all sides of them then they feel equal pressure from all directions because of low altitude. The pressure near ocean level is the same as that of when we standing on the land.

Hydrostatic pressure in ocean

When a person dives into the ocean even a few feet, remarkable changes occur you can feel an increase of pressure on your eardrums because of hydrostatic pressure. If the person dives into the ocean the diver reaches 33feet then the pressure is double what it was at the surface. For every 33feet hydrostatic pressure increases by 1atm. Hydrostatic pressure is one of the main reasons why so little of the ocean floor has been explored.

Measurement of pressure in ocean

At the ocean surface we feel 1atm as we descend into the ocean we feel 1atm for every 10m increase in depth. So at 1000m depth the pressure would be 101atm, if we consider the depth of ocean would be 3800m the pressure would be 381times greater than the pressure at the surface.

Ocean currents under pressure in ocean

In a homogeneous ocean having a constant potential density, if the surface of the ocean is tilted then the horizontal pressure differences are possible. In this case, isobaric surfaces are tilted in the deep layers by the same amount as a barotropic field of mass. The unvaried pressure gradient gives current speed uncommitted of depth. The horizontal gradient of pressure is much smaller than the vertical changes in pressure given ocean currents.

Ambient pressure in ocean

Ambient pressure is a junction of the hydrostatic pressure and the atmospheric pressure on the free surface. This increases approximately linear depth, and much greater changes in ambient pressure can be experienced underwater. At ocean level, ambient pressure is about 14.7 pounds per square inch.

Submarine survive water pressure in ocean

Submarines have two hulls, one inside the other, to help them survive, outer hull is waterproof and the inner one is called a pressure hull which is stronger and preventive against immense water pressure. A submarine can control its buoyancy in the ocean. Depending on the depth of the submarine, when the submarine is in dived condition facing external seawater pressure. A submarine can dive is about 2,000feet.

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Submarine in ocean pressure image credit: pixabay

Water pressure at the bottom of Mariana trench in ocean

The deepest know point in an ocean is called as Mariana trench. The water pressure at the bottom of the trench is crushing eight tons per square inch. Piccard’s fish was a sea cucumber it is thought that pressure is so great that calcium cannot exist except in solution. So living near the Mariana trench is impossible for life because of extreme water pressure.

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17+ Negative Pressure Example: Detailed Facts

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Negative pressure is defined as “Generated pressure, where the pressure is smaller in one place relative to another place”, that is the pressure below the atmospheric pressure.

In general, the negative pressure can also be stated as ”When the enclosed area has the lower pressure than the area around it, that is when the force will be applied on you by the body.”

This post gives you a detailed explanation of such negative pressure examples

  1. Stretching of certain solids
  2. Cavitation of liquid
  3. Pull of Suction cups
  4. Negative pressure during respiration
  5. Negative pressure in medium
  6. Intrapleural pressure
  7. Negative pressure during Gas released into an empty volume
  8. Negative pressure in syringes
  9. Negative pressure in Dark energy
  10. Plants transport water under negative pressure
  11. Negative air pressure in pharma industries
  12. Shrinkage of solid sphere
  13. Negative pressure under isolation
  14. Negative pressure in deep well jet pumps
  15. Negative pressure in Sucking on a straw
  16. Negative pressure in fluid mechanics
  17. Trees make negative pressure on water
  18. Negative pressure wound treatment

Detailed explanation of Negative pressure examples

In this section, you will learn a detailed explanation of the above-mentioned negative pressure examples.

Stretching of certain solids

We can see negative pressure in solids, we call it negative pressure tension, it happens When we stretch the solid, solids can militate or resist the forces due to the internal attractive force between its molecules

Cavitation of Liquid

When a negative pressure is applied to the liquid, the static pressure of the liquid reseats to down the liquid-vapor pressure leading to the layout of small vapor-filled cavities in the liquid. That is when the negative pressure reaches nearly 9MPa, cavitation occurs.

Pull of suction cups

Suction cups are made up of PVC plastic when a suction cup is sealed inversely on a surface and air is kneaded out of the cup, a negative pressure region is formed inside the suction area, and this negative pressure presses down inside the cup, that creates the suction.

Negative pressure during Respiration

We can see negative pressure in respiration, if we increase the extension of a space the pressure drops, breathing in with the infringement of the chest wall and abdominal wall increases the capacity, pressure drops and the outside air rushes in. in other words we can say that when we inhale, the diaphragm and muscles between our ribs contract, creating a negative pressure inside your chest cavity. The negative pressure draws the air that we can breathe into our lungs.

negative pressure example
Negative pressure in lungs during respiration
image credit: pixabay

Negative pressure in medium

When we applied negative pressure to the medium, the expansion of the medium requires work, when a medium is allowed to contract, energy is released that can be used to do useful work.

Intrapleural pressure

The space between the lung and pleura is intrapleural pressure which is a negative pressure because the movement of the lungs Rely upon the pressure inclination among the lungs and pleura. The pressure inside the pleural cavity is generally smaller than the atmospheric pressure, hence, in turn, to operate the air inside the lung, the intrapulmonary pressure and the intrapleural pressure should be negative.

Negative pressure during gas released into an empty volume

Negative pressure was possible when gas was released into an empty volume after some high duration of more or less constant expansion as if owt were absorbing it even order.

Negative pressure in syringes

When we fill a container or bowl with a liquid-like syringe, if the dilute gas is not there in the liquid, the size of the container increases slowly, then there is a possibility of obtaining the negative pressure.

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Negative pressure in syringes
picture credit:
pixabay

Negative pressure in dark energy

Dark energy is a form of energy postulated to act in opposition to gravity and to occupy the entire universe to accelerate, the gravitational effect of dark energy is repulsive because the dark energy has strong negative pressure, this negative pressure causes a gravitational repulsion, hence the dark energy helps in the expansion of the universe to accelerate.

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Negative pressure in dark energy picture credit: pixabay

Plants transport water under negative pressure

The transport process inside the plants mainly occurs in the xylem tissue, xylem sap is transported under negative pressure which means that tension is applied to xylem sap, which can sustain the forces because of hydrogen bonds between water molecules, in plants negative pressure is a result of transpiration, when the sap is under negative pressure the gas bubbles are formed such that the liquid is under tension and is thermodynamically metastable concerning vapor phase.  Negative pressure makes it easier to control and maintain or keep temperature, humidity, carbon dioxide levels, and other contaminants.

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plants transport water under negative pressure
picture credit: pixabay

Negative air pressure in pharma industries

In pharma industries, negative air pressure maintains the rooms to be clean and is essential to preventing cross-contamination this kind of negative air pressure room are suitable for steroid and chemotherapy.

Shrinkage of solid sphere

When you extract all gas from the sphere up to zero atmospheric pressure and something more. Then solid sphere will try to shrink then we can say that it will be negative pressure.

Negative pressure under isolation

Negative room pressure is an isolation technique used in hospitals to prevent cross-contamination from room to room, it includes ventilation that generates negative pressure to allow air to flow into the isolation room but not escape from the room. Negative pressure rooms in hospitals keep patients with infectious illnesses away from other patients.

Negative pressure in deep well jet pumps

The pumping effect is achieved by using a motive medium such as a gas flow, this produces a dynamic pressure drop in a motive nozzle resulting in negative pressure which accelerates the suction medium by impulse transmission in the mixing nozzle tow throughout. Negative pressure at the deep jet well pumps is when the hydraulic grades at the pump are below their elevation, which occurs generally on the suction side of the pump this suction side is the negative pressure point. The simple technical jet pumps are especially robust and low defensible.

Negative pressure in sucking on a straw

When we suck the liquid on a straw it creates negative air pressure to cause a liquid to flow through a tube against gravity. If the straw has a narrow diameter then we require a greater effort to suck because greater negative pressure is needed to overcome the higher resistance offered by the smaller straws, in another way we can say that, when we drink a juice using a straw the air pressure inside the straw decreases. Due to our sucking the negative pressure is created inside the straw which forces the liquid up along the straw and into our mouth.

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Negative pressure in sucking straw
picture credit: pixabay

Negative pressure in fluid mechanics

Under certain conditions, liquid can stretch, if we pull them they pull back. For example when holding the glass full of water, then the fluid exerted pressure on the glass wall and the glass also exerted equal and opposite pressure on the fluid surface this is because of the stress or tension resulting from the elongation of an elastic body that pressure is negative pressure.

Trees make negative pressure on water

As trees perspire, they lose molecules hence in the stomata of the tree molecular density decreases this lowers the pressure even more negatively. Negative pressure happens when trees undergo transpiration then the water diffuses out the tree leaves at the top and most of the water that scatters the top of the tree.

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Negative pressure in tall trees
picture credit: pixabay

Negative pressure wound treatment

Negative pressure wound treatment is an advanced technique that will be helping in the healing of the wound in a better and faster way. Negative pressure wound treatment includes the packing of the wound in a sterile or infertile way and a vacuum pump is connected to the dressing so the extra secretions which are being formed inside the wound will be withdrawn with the help of a vacuum, once the machine is on the wound is slowly being pulled together in second.

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