Definition of Solar Energy
Solar energy is energy that comes from the sun. Every day the sun radiates, or sends out, an enormous amount of energy. The sun radiates more energy in one second than people have used since the beginning of time!
Where does all this energy come from? It comes from within the sun itself. Like other stars, the sun is a big gas ball made up mostly of hydrogen and helium. The sun generates energy in its core in a process called nuclear fusion. During nuclear fusion, the sun's extremely high pressure and hot temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. But the helium atom weighs less than the four nuclei that combined to form it. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.
It takes millions of years for the energy in the sun's core to make its way to the solar surface, and then just a little over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of light.
Only a small portion of the energy radiated by the sun into space strikes the earth, one part in two billion. Yet this amount of energy is enormous. Every day enough energy strikes the United States to supply the nation's energy needs for one and a half years!
Where does all this energy go? About 15 percent of the sun's energy that hits the earth is reflected back into space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produce's rain-fall. Solar energy also is absorbed by plants, the land, and the oceans. The rest could be used to supply our energy needs.
From the beginning, the sun has been personified and worshipped for the light and heat that it provides to the earth. Eventually the worship of the sun was replaced with a more practical approach. Humans have never known a planet without a sun, when it is cold we all look for a sunny spot.
The massive potential of solar energy is almost too hard to grasp, which is why harnessing this Sun’s energy for useful purposes has sparked the interest of many scientists for thousands of years. This article consists of a timeline over milestone historic events around human’s efforts to extract solar energy.
Photovoltaics are devices that use what is known as the photovoltaic effect to generate electricity from sunlight. Knowledge around this phenomenon has only been around for about two centuries, which is why the history of solar cells (photovoltaics) begins in the middle of the article.
Where it all began ?
700 BC – Sunlit Fires
We know that all the way back to the 7th century B.C., humans figured out how to make fires by concentrating the sunlight with magnifying glass.
214–212 B.C. – Archimedes’ Heat Ray
Arichimedes and his burning mirrors
1767 – The First Solar Oven
A solar oven, or solar cooker, uses sunlight to heat meals or drinks. These devices are only reliant on sunlight to work – there is no fuel required.
Already in 1767, the first solar oven was invented. The credit goes to Horace de Saussure, a Swiss physicist, which probably had no idea his invention would help people prepare their dinner two and a half centuries into the future.
1839 – The Discovery of the Photovoltaic Effect
1839 marks a big year in the history because Edmund Becquerel, a French physicist, only 19 years old at the time, discovered that there is a creation of voltage when a material is exposed to light. Little did he know, that his discovery would lay the foundation of solar power.
1873 – Photoconductivity in Selenium
Willough by Smith, an English engineer, discovered photo-conductivity in solid selenium.
1876 – Electricity from Light
Building on Smith’s discovery three years before, professor William Grylls Adams, accompanied by his student, Richard Evans Day, were the first to observe an electrical current when a material was exposed to light.
1883 – The First Design of a Photovoltaic Cell
An American inventor, Charles Fritts, was the first that came up with plans for how to make solar cells. His simple designs in the late 19th century were based on selenium wafers.
1905 – Albert Einstein and the Photoelectric Effect
He formulated the photon theory of light, which describes how light can “liberate” electrons on a metal surface.
1918 – Single-Crystal Silicon
Jan Czochralski, a Polish scientist, figured out a method to grow single-crystal silicon.
1954 – The Birth of Photovoltaics
David Chapin, Calvin Fuller and Gerald Pearson of Bell Labs are credited with the world’s first photovoltaic cell (solar cell). In other words, these are the men that made the first device that converted sunlight into electrical power.
Types of Solar Energy
We have been using various types of solar energy since ages, in this way or the other. Earlier it was used for drying clothes, grain etc.In India the Solar Energy is used even today to make food items like papad’s, dried peppers & chillies. Solar energy has always been there but was overlooked until recent times.
Now the question arises, what are the types of solar energy?
We can easily classify solar energy according to its basic use.
1) Passive Solar Energy
2)Active Solar Energy
Solar energy is also classified how it is transformed and used.
- Photovoltaic solar power
- Solar Thermal Energy
- Concentrated Solar Power
Let’s dive in to know more about all these five categories of solar energy.
1) Passive Solar Energy
Passive Solar Energy is a method in which solar energy is harnessed in its direct form without using any mechanical devices. Drying Clothes in daylight is an example of using solar energy passively.
Passive Solar Energy has a few applications which all of us can use (where ever there is sunlight).
- Passive Solar Heating
- Passive Solar Cooling
2) Active Solar Energy
The Active Solar Energy employs mechanical or electrical equipment for functioning and increase system efficiency. As an example water pumps are used to circulate water through the active solar energy water heating system.
Some Applications of Active Solar Energy which can be very helpful to all of us.
- Active Solar Water Heating
- Active Solar Pool Heating
- Active Solar Space Heating
1.Photovoltaic Solar Power
The Energy generated by incident solar energy (light) into electricity is termed as Photovoltaic Solar Power. This is done using Photovoltaic Solar Cells.
Every one of us can get the benefits of the applications of photovoltaic solar power.
- Solar Electricity
- Photovoltaic Solar Lighting
- Photovoltaic Cooling
2. Solar Thermal Energy
Solar Thermal Energy is the heat energy derived from the incident solar energy (sunlight). This is used by Solar Heating Panels.
Yes, you guessed it right. Solar Thermal Energy does have advantages like other forms of solar energy.
- Solar Water Heating
- Solar Pool Heating
- Solar Space Heating
These are the common uses of Solar Thermal Energy. By taking advantage of these you can get plenty of benefits. Electricity can be generated using solar energy commonly this is known as Solar Thermal Electricity
3. Concentrated Solar Power
Concentrated Solar Power is a branch of Solar Thermal Energy which is used to generate solar power electricity.
Electricity is produced on a large scale by using this technology. This technology is not in either of our scope. But we can surely get its benefits from a renewable energy supplier or green power from the electricity supply company.
The sun is probably the most important source of renewable energy available today.
Traditionally, the sun has provided energy for practically all living creatures on earth, through the process of photosynthesis, in which plants absorb solar radiation and convert it into stored energy for growth and development. Scientists and engineers today seek to utilize solar radiation directly by converting it into useful heat or electricity.
Two main types of solar energy systems are in use today: photovoltaics, and thermal systems. There is a great deal of opportunity for using these systems in the state of Pennsylvania, and ongoing work at Penn State is seeking to improve the available technology and increase the utilization of solar energy systems in the keystone state.
Surprising study finds that solar energy can also cause climate change (a little)
Large solar arrays could have some surprising side effects, according to a new study, including causing changes in the local climate.
On a global scale, these changes will be minor compared to what would happen if humans continue to burn fossil fuel for energy instead, but are still worth watching, scientists say.
Previous studies have shown that both solar arrays and wind farms have the potential to cause regional changes in temperature and precipitation by altering the amount of solar radiation absorbed by the Earth or disrupting local airflow patterns.
Solar panels change the way sunlight is reflected and absorbed by the Earth. Any radiation they take in is radiation that’s not being absorbed by the Earth. This leads to a cooling effect in the region surrounding the array. In fact, the first two simulations in this study, which assumed solar panel installations throughout the world’s desert and urban areas, produced a 2-degree Celsius regional cooling in the desert regions. This cooling was also associated with a 20 percent decrease in precipitation in the deserts. Other, slightly broader changes in precipitation and wind patterns occurred as a result in the regions surrounding the deserts.
In urban areas, the effects were a little different. In the first simulation, the model predicted a very small amount of cooling, with temperature falling approximately 0.26 degrees Celsius. In the second simulation, the one in which global thermostat regulation is significantly increased, the large amount of power consumed actually produced an urban heat island effect, in which human energy use releases heat into the environment and causes the regional temperature to warm up. In this scenario, the warming from the heat island effect essentially compensated for the cooling caused by the solar panels.
When considered on a global scale, these effects become much smaller. In the first simulation, the average change in global temperature is an average decline of about 0.34 degrees Celsius, relative to the temperature that would be expected under the same low-carbon climate scenario with no solar parks. In the second simulation, where the heat island effect is taken into account, there would be an average increase in global temperature of about 0.09 degrees Celsius.
So future research may also examine how the distribution of solar arrays could be changed in order to maximize their positive effects on land use and minimize their negative ones.
In the meantime, this study reinforces the idea that a transition to renewable energy is imperative to protecting Earth’s climate future. While the transition won’t be without its own effects, the authors note that the alternative — a world in which fossil fuel burning is allowed to continue unabated — would be far worse.
Effects(on plants, animal, human being, earth)
We use electricity to fuel our homes and business to power our appliances and to supply light. to get electricity we tend to use burning fossils, burning of coal and use nuclear. These kinds of electricity generation manufacture greenhouse gases, that contribute to global warming, produce harmful bio product like acid rain, unpleasant smell, it releases CO2, pollute the air, pollute water, and manufacture toxic industrial waste.
The sun has been around for over four billion years, it's the most benefactor for all life on earth and our solar system. Why not utilize it for our energy demand to supply clean electricity through the sun’s solar energy with less impact on human, animals, the atmosphere and all living things.
Below are lists of the positive impact of solar energy on human, animals and therefore the environment.
Solar energy impact on Human
Solar Energy is one of the cleanest sources of renewable energy.
Does not release any gas, produce any nose, doesn't soil the air we breathe or ground.
Once the solar system is install, it provides free energy and may last for over 25-50 years. On the long-term solar system can save you lots of money on energy price.
Virtually there's no maintenance needed and you'll always add new solar panels to your solar system if you need a lot of energy.
Solar energy is renewable and widely accessible.
You can sell the access energy your solar panels manufacture back to the national grid and this drastically lower your electricity bill.
You don’t need to be connected to the national grid to get electricity, so you'll use solar systems in isolate locations without having to have long wires connecting to the national grid.
The main impact is extra money into the user wallet because you'll get free electricity for a very long term and it'll pay itself many times over.
Having solar panels install to your home will increase your home price.
Can be use to warm water on hot water heaters and cook food with solar ovens.
Solar energy impact on Animals and Plants
There is no huge impact on animals with solar energy except when they are transporting and producing solar panels.
Plants want photosynthesis, photosynthesis in plants use the sunlight from solar energy. without sunlight plants can die as well as different living creatures.
Solar energy impact On Earth
The factors needed to determine the ideal location of a solar power plant include lots of open flat areas, lots of sunshine, and no shadowing trees or buildings. The infrastructure (basic building facilities and installations) required to develop solar energy is a solar power plant to make power and the electrical grid for power distribution.
Environmental Impacts of Solar Energy - negative
Land Use and Ecological Impacts
In the purpose of generating electricity at a utility-scale, solar power facilities necessitate large areas for collection of energy. as a result of this, the facilities may interfere with existing land uses and can impact the use of areas like wilderness or recreational management areas. As energy systems may impact land through materials exploration, extraction, producing and disposal, energy footprints will become incrementally high. Thus, some of the lands could also be used for energy in such a way that returning to a pre-disturbed state necessitates important energy input or time, or both, whereas different uses are so dramatic that incurred changes are irreversible.
Impacts to Soil, Water and Air Resources
The construction of solar facilities on huge areas of land imposes clearing and grading, leading to soil compaction, alteration of drainage channels and raised erosion. Central tower systems need consuming water for cooling, which may be a concern in arid settings, as a rise in water demand may strain offered water resources as well as chemical spills from the facilities which may lead to the contamination of groundwater or the ground surface.
As with the development of any large-scale industrial facility, the construction of solar energy power plants will create hazards to air quality. Such threats include the release of soil-carried pathogens and results in a rise in air stuff that has the impact of contaminating water reservoirs.
Environmental Impact of Solar Energy - positive
The biggest effect is solar energy doesn't release nitrogen oxide, CO2, sulpher dioxide, or mercury into the atmosphere. that mean solar energy doesn't contribute to global warming, acid rain, or smog.
Does not produce any noise because there are no moving components, doesn't let out unpleasant smell.
Solar energy from the sun is widely abundant and offered around the world.
Materials use to make solar panels are recyclable, at the end of its life you can recycle the components therefore it produce little pollution to impact the surroundings.
The only pollution from solar energy is the producing of solar panels and transporting it, however the pollution is very little when compare to different sources of energy like coal or nuclear.
The sun heats the oceans that leads to wind.
The environmental impact of solar energy depends on the size of the solar project and what the energy is eventually used for.
Large scale solar energy projects will have a larger effect on the surroundings, both positively and negatively.
Unlike fossil fuels, solar power emits no CO2 into the atmosphere, thus using solar power leads to a lower proportion of greenhouse gasses being emitted into the atmosphere. One energy technology company estimates that converting the whole electric grid to solar power would minimize greenhouse gasses within the atmosphere by four-hundredth.
Also solar energy systems are quiet, and usually haven't any loud moving components so they don't release any form of irritating noise pollutions.
Unfortunately, solar energy panels will only absorb light when the sun is shining, thus solar systems are usually times required to be very large in order to be efficient. These major systems will use a major quantity of area and land, which can have negative impact on the surrounding environment and animal life. Clearing land to create major scale solar energy systems will negatively impact the surroundings by disturbing ecosystems and removing plant life.
Also, the manufacturing of solar panels will have a negative impact on the surroundings. solar panel manufacturers release greenhouse gases and different pollutants into the atmosphere during the producing and doping method of solar panels. Transportation of solar panels will also have a negative impact on the surroundings if fossil fuels are used during transportation.
Every solar panel that's designed and successfully used as a substitute for fossil fuels is reducing the amount of pollutants released into the atmosphere. By all of these, using solar energy as a substitute for fossil fuels can have a positive impact on the environment.
Installing solar systems is a risky business. Lifting and arrangement unwieldy solar panels, the potential for falls off many-storied rooftops, panels that heat up as soon as they’re uncovered – these are a number of the serious hazards that solar employees face. They’re also subject to the risks of traditional roofing, carpentry and electrical trades – a number of the most injury-prone occupations around.
The occupational Safety and Health Administration (OSHA) needs employers to implement safety training and protection for their workers. several solar installation firms have taken OSHA’s requirements a step farther, making manuals of their own that detail the particular measures they need to manage solar energy safely.
Safety issues are common for solar installations, however proactively putting preventive measures in place will facilitate mitigate on-the-job injuries.
Every Worksite Presents completely different Risks
No two worksites are a similar. Before a solar installation begins, it’s essential for the installer to visit the site, determine the security risks and develop specific plans for addressing them. Plans ought to include:
⦁ Equipment to be used for safe lifting and handling of solar panels
⦁ Type and size of ladders and scaffolding if required
⦁ Fall protection for rooftop work
⦁ Personal protective instrumentation for each installer
All instrumentation required for the duty should be inspected and verified to be in good working order before being brought to the worksite.
Lifting and Handling solar Panels
Solar panels are heavy and awkward to raise and carry. Loading and unloading panels from trucks and onto roofs can cause strains, sprains, muscle pulls and back injuries as well as cumulative trauma that stresses the spine. The panels may also heat up quickly when exposed to sunlight, causing burns if not handled safely.
Safety measures for solar workers:
- Lift every solar panel with at least two people while applying safe lifting techniques.
- Transport solar panels onto and around the work site using mobile carts or forklifts.
- Never climb ladders while carrying solar panels. to get solar panels onto rooftops, use properly inspected cranes, hoists or ladder-based winch systems.
- Once unpackaged , cover panels with an opaque sheet to stop heat buildup.
- Always wear gloves when handling panels.
- Ladder Safety
- Solar construction often involves working on roofs and from ladders. selecting the proper ladder and using it properly are essential.
- Select the ladder that best suits the necessity for access – whether a stepladder, straight ladder or extension ladder. Straight or extension ladders should extend a minimum of 3 feet higher than the rung that the employee can stand upon.
- Select the proper ladder material. aluminum and metal ladders are the most usually used nowadays and will have their place on the job, but they’re a serious hazard near power lines or electrical work. Use a fibreglass ladder with non-conductive side rails near power sources.
- Place the ladder on dry, level ground removed from walkways and doorways, and a minimum of ten feet from power lines and secure it to the bottom or upper side.
Solar Electrical Safety
Solar electrical (photovoltaic or PV) systems embrace many elements that conduct electricity: the PV solar array, an inverter that converts the panel’s DC to AC, and different essential system components. when any of those elements are “live” with electricity generated by the sun’s energy, they will cause injuries related to electrical shock and arc-flash. Even low-light conditions will produce adequate voltage to cause injury.
It’s also necessary to acknowledge that with PV systems, electricity comes from 2 sources: the utility company and therefore the solar array that's absorbing the sun’s light. Even when a building’s main breaker is shut off, the PV system can continue to produce power. This makes isolating the power source more difficult, and needs further caution on the part of the solar employee.
Safety measures for solar workers:
- Cover the solar array with an opaque sheet to “turn off” the sun’s light.
- Treat the wiring returning from a solar PV array with a similar caution as a utility cable.
- Use a meter or circuit take a look at device
- To make sure that each one circuits are de-energized before working on them.Lock out the power on systems that can be secured out. Tag all circuits you’re functioning on at points wherever that instrumentality or circuit may be energized.
- Never disconnect PV module connectors or different associated PV wiring once it's below load.
Personal protecting equipment
Personal protective equipment is an important part of each solar installation. It’s the employer’s job to assess the workplace for hazards and supply the PPE deemed necessary for the employee’s safety. Hard hats, gloves and steel-toed shoes with rubber soles are among the usually needed PPE for solar projects.
Employees are in turn responsible for using PPE in accordance with their employer’s directions, maintaining it during a safe and reliable condition and requesting replacements once necessary.
Risk is an element of running any business, however once it involves an employee’s safety and health, risk should be avoided in the least value. Proactive safety designing and its successful implementation on the work will facilitate ensure that accidents don’t happen.
Advantages of Solar Energy
Solar energy is widely available and unlimited. No air or water pollution is given off when solar panels are used for energy production. It does not require transport of fuels or disposal of waste products. Solar energy produces electricity very quietly so it can be used in residential areas without creating noise pollution. Solar panels can be installed on top of many rooftops. Therefore, large amounts of open areas or not required for typical household use. Solar panels do not require a direct connection to the grid.
Solar energy has the ability to make electricity in remote locations that are not linked to the grid. This is more cost efficient than running long sets of wires into remote locations.
Disadvantages of Solar Energy
The initial cost of solar cells can be quite expensive, typically over $1000 per solar panel and may cost up to $20,000 to convert a typical home. Solar energy is only able to generate electricity during day light hours. Energy must be stored for later use in battery systems. Weather or smog may also limit the efficiency of solar energy, however new technologies are being developed to overcome this obstacle.
Large area solar farms can create heat islands or cause ecological damage such as habitat loss. Solar farms also require a large area (up to thousands of acres) and therefore have a large land footprint. However, the sunniest areas such as arid environments are not heavy vegetated, and habitat disruption is less than it would be in forested regions. Residential applications do not result large-scale ecological damage; however, some habitat loss is experienced due to tree removal designed to improve sun exposure for rooftop panels.