What Is It?

Solar Power

By definition, solar energy is energy radiated from the Sun in the form of heat and light and harnessed as solar power.

So basically, solar power is power from the Sun. This energy is converted into other forms of energy

as heat and electricity. Thermal energy is used to heat water in homes,

buildings and swimming pools.It is used to heat spaces such as homes,

greenhouses and other buildings. Lastly, it is used for heating fluids at a high

temperature to work turbines to create electricity.

What Is Solar Power?

Solar Energy Converted into Electricity in 2 ways:

• Photovoltaic

• Concentrating Solar Power Plants

What is it used for?

Photovoltaic (PV) is the change of sunlight directly into electricity. Single PV cells are clustered into panels and placed in proper order of panels that are used in a wide range of applications.

For example, single small cells that charge calculator and watch batteries, to system that power single homes, to a large power plant covering many acres.

Concentrating solar power plants generates electricity by using the heat from thermal collectors to heat fluids that produce steam that is used to power the generator.

There are 11 known concentrating solar power generating units operating in the US. Nine of these are in California, one in Arizona, and one in Nevada.

What is it used for?

Solar energy has two main benefits: it does not produce any air pollutants or carbon-dioxide and when solar panels are located on buildings, they don’t have a big impact on the environment.

Because the sun doesn’t deliver much energy to one place at one time, a large surface is required to harness energy at a useful rate.

The amount of sunlight that comes to Earth’s surface is not the same every time. It varies depending on the season, time of day, location, and the weather conditions

Solar energy is the most available source of energy on Earth. Solar power provides total current energy on demand.

It is an intermittent energy source, which means, it is not available at all times.

It can be reinforced to extend thermal energy storage; for example: natural gas or hydropower. Solar Power Generating Systems (SEGS) VIII and IX

located in California are collectively and individually the largest solar power generating plants in the world.

Solar Power technology uses mirrors to reflect and concentrate sunlight onto receivers which collect the energy and convert it to heat. This heat can be used to produce electricity via a steam turbine.

Where It’s Found

Low-temperature solar collectors also absorb the sun's heat energy, but instead of making electricity, use the heat directly for hot water or space heating in homes, offices, and other buildings.

Covering 4% of the world's desert area with photovoltaic could supply the equivalent of all of the world's electricity.

The Gobi Desert alone could supply almost all of the world's total electricity demand.

A photovoltaic cell, also known as a solar cell or PV, is the technology used to convert solar energy straight into electrical power.

A photovoltaic cell is a non-mechanical device that is usually made from silicon alloys.

Solar Photovoltaic

Sunlight is made up of photons, or solar energy particles.

Photons are composed of energy, which can vary in amount due to the different wavelengths in the solar spectrum

When photons touch photovoltaic cells, they can either reflect, pass through, or be absorbed; only absorbed photons can be converted into electricity

When enough sunlight is absorbed, the electrons dislodge, creating more room for more electrons to attract to the surface.

After several electrons travel to the cell, it creates an imbalance in electrons, and a voltage potential, like a battery, so the electricity can flow.

Flow of Electrons

The PV cell is the building block for a PV system. Single cells can vary in size from 0.5 inches to almost 4 inches

across. One cell only produces 1 or 2 watts; that isn’t enough power for most

applications. To increase the output of power, cells are electrically connected to a

packaged weather-tight module. Modules are further connected to form an array, which means, to the

entire generating plant, whether it’s made of one or several thousand modules.

The number of modules connected together in an array depends solely on the amount of power output needed.

The performance of a PV array depends upon sunlight. Climate conditions have a big effect on the amount of solar power

received by a PV. Modern modules are 10% efficient in converting sunlight.

How Photovoltaic Systems Operate

The simplest photovoltaic systems power small wrist watches and small calculators used in everyday life.

Other complicated systems provide electricity to pump water, power communications equipment, and it provides electricity to homes.

Photovoltaic cells are like batteries, as already said. They generate direct currents (DC), which is used for

small loads or electronic equipment.When DCs from PV cells are used for commercial

reasons or sold to electric utilities using the electric grid, it must convert to alternating currents (AC) using inverters, a device that converts DC power to AC.

What are PV systems used for

 Solar thermal power plants use the sun’s rays to heat

fluid at high temperatures.After, the fluid circulates through pipes so it can transfer

hate to water and produce steam. The steam is converted into mechanical energy in a

turbine and turned into electricity by a conventional generator.

Solar thermal power generation works the same as fossil fuels except that instead of using stream from combustion of fossil fuels, the steam is produced by heat collected from sunlight.

Solar thermal technologies use concentrator systems to meet high temperatures need to heat the fluid.

Solar Thermal Power Plants

Parabolic troughs are used in the largest solar power facility in the world, and it’s located in the Mojave Desert at Kramer Junction, California.

A parabolic trough collector has a long parabolic-shaped reflector that focuses the sun’s rays on a receiver pipe located at the center of the parabola.

It tilts with the sun when the sun moves away from the east and the west to make sure that the sun is always focused on the receiver.

Because of its shape, a trough can focus the sun at 30 to 100 times its normal intensity on the receiver pipe located on the focal line, going over 750 degrees Fahrenheit.

A solar field has several parallel rows of solar parabolic trough collectors on the north horizontal axis.

Parabolic trough

The three main types of solar thermal power systems are:

Parabolic trough

Solar dish

Solar power tower

•Parabolic trough•Solar dish•Solar power tower

•Parabolic trough•Solar dish•Solar power tower

•Parabolic trough•Solar dish•Solar power tower

•Parabolic trough•Solar dish•Solar power tower

A heat transfer fluid is heated as it circulates through the receiver pipes and returns to a series of heat exchangers at a central location.

After made into steam it is fed to a conventional steam turbine and able to produce electricity.

When the hot fluid passes through the heat exchangers, it cools down, and is then recirculated through the solar field to heat up again.

The plant is usually designed to operate at full power using solar energy alone.

However, all parabolic trough power plants can use fossil fuel combustion to supplement the solar output during periods of low solar energy, such as on cloudy days.

A solar dish system uses concentrating solar collectors to track the sun, so they always point to the sun and concentrate the solar energy at the focal point of a dish.

Solar dishes reach temperatures over 1380 degrees Fahrenheit.

The operating equipment, used with a solar dish can be mounted at the focal point of the dish, making it well suited for remote operations, the energy might be collected from a number of installations and converted onto electricity.

The engine in a solar dish system converts heat into mechanical power by adding pressure when a fluid is cold, heat the compressed working fluid, and then expanding the fluid through a turbine or with a piston to produce work.

The engine is coupled to an electric generator to convert the mechanical power to electric power.

SOLAR DISH

A solar power tower generates electricity from sunlight by focusing concentrated solar energy on a heat exchanger mounted on a tower.

This uses hundreds of thousands of heliostats, flat sun tracking mirrors, to reflect and concentrate the sun’s energy onto a solar power tower. The energy can be concentrated as much as 1,500 times that of the energy coming from the sun.

Energy losses from thermal energy transport are minimized as solar energy that is transferred by reflection of the heliostats to a single receiver.

Power towers are large and economical. Along with a number of electricity utilizes, the U.S.

Department of Energy, built and operated solar power tower near Barstow, California, during the 1990s.

Solar Power Tower