To make the Sun a major source of power for mankind, we have to understand how does solar energy work and to turn the tremendous amount of power sent to us by the Sun every second into a reliable source of clean electricity and heat for us.
Today, fossil fuels still represent the main source of electricity for our civilization, but luckily, the generation capacity for solar and wind energy grows every year, which reduces the amount of greenhouse gas emissions released into the atmosphere.
How Does The Sun Produce Energy?
The huge amount of power produced by the Sun every day, is generated by the massive fusion reaction process of hydrogen, that takes place in its core.
The core that extends to about 25% of the solar radius, is the place where the nuclear fusion reaction is produced due to the immense pressure (about 250 billion atmospheres or 3.67 trillion psi) and heat (15 million Kelvin) present there.
The nuclear fusion reaction of hydrogen fuses four hydrogen atoms to produce one helium atom, and releases a huge amount of energy in the form of light and heat.
All this energy (about 3 trillion watts every day), sustains all life processes on the planet, and is also used actively and passively to naturally illuminate and heat homes, and also to produce clean electricity for homeowners, companies and the grid.
How Does Solar Power Work?
Today, the sunlight is used in two different ways to produce clean and free electricity: using photovoltaic solar panels (PV solar) and large mirrors that concentrate the sunlight into a focal point where an agent is located (oil or melted salt), and heated at high temperatures to produce steam and generate power using a turbine and a powerful generator (solar thermal technology).
If you are interested to know more about renewable energy, read every day solar energy news to remain informed about everything new in the field.
The Photovoltaic Effect
Photovoltaic solar cells produce energy by converting the sunlight into electricity through the ‘photovoltaic effect’.
The ‘photovoltaic effect’ (was discovered in 1839 by Alexandre-Edmond Becquerel), also known as photovoltaics, is a physical and chemical phenomenon (closely related to the photoelectric effect) used to create electrical energy in a semiconductor material due to the exposure to light.
Using this chemical and physical phenomenon, any type of photovoltaic solar cell can generate electricity in the presence of the light.
Solar cells work at maximum capacity in the hot sunny days, and have a diminished production of electricity in the winter.
Solar Thermal Technology
Solar thermal technology, also known as solar thermal power or concentrated solar power (CSP), is another form of renewable energy that uses the heat radiated by the Sun to produce clean electricity on a large scale.
Unlike photovoltaic (PV) technology that relies on the sunlight, solar thermal technology uses the Sun’s heat to warm a fluid and produce steam that will spin a turbine to generate electricity.
There are several technologies used to produce thermal solar power, such as: parabolic trough technology and central tower technology.
Parabolic Trough Technology
Parabolic trough technology uses parabolic mirrors to reflect and concentrate the solar radiation onto a pipe located in the focal line of the mirrors.
Inside the pipe, a thermal fluid (agent) is heated to reach a temperature of about 400°C (752°F). In the heat exchanger, the thermal fluid will transfer its heat to water which will be turned into steam and then used to drive a turbine and produce electricity using a generator.
The steam is then cooled down to restart the process.
Central Tower Technology
Central tower technology uses very large flat mirrors (heliostats), to concentrate the sun’s radiation at a point located at the top of the tower where an agent (molted salt) is located.
The agent is heated by the sun’s radiation to reach temperatures around 700°C (1,292°F), and produce steam that will spin a turbine and generate electricity using a large and powerful generator.
Solar thermal technology is more reliable than PV technology, because heat can be stored by the agent to produce electricity during the night or during cloudy days.
Producing electricity on a large scale, solar thermal technology contributes to the reduction of the greenhouse gas emissions released every year.
How Do Solar Panels Work?
There are several types of solar panels used today to produce electricity using the sunlight, and heat water using the sun’s radiation (thermal and thermodynamic panels).
Photovoltaic Solar Panels
Photovoltaic (PV) solar panels rely on photovoltaic cells that are converting the sunlight into clean electricity through the photovoltaic effect.
The clean electricity produced by the panels is DC (direct current) electricity, and can’t be used to power homes and businesses.
This is the reason why the electricity produced during the day by the PV panels, is stored in a battery (for later use), or sent to the charge regulator/controller and from there to the inverter, to be transformed into AC (alternative current) electricity, which is used to power your appliances.
Thermal Solar Panels
Thermal solar panels rely on the presence of the sunlight to heat water using a solar thermal collector.
The thermal collector facing the sun will heat an agent (working fluid), which will be stored and used to produce warm water.
There are solar thermal panels using only water (without the working fluid), and systems that use both water and a working fluid.
This type of solar panels is used to produce warm water for domestic use, to heat pools, homes and businesses.
Thermodynamic Panels
This type of solar panels can be considered a revolution in the solar sector because a single panel (2 by 0.8m) and a water tank (with heat exchanger) can produce hot water (24/7 and all year long), despite the outside weather conditions because they work well in sunny, rainy, windy and even snowy days.
If you relied on an electric water heater to produce hot water for domestic use (high energy bills), a thermodynamic solar panel can make the difference by producing hot water for your family or business all year long, without consuming much energy (you will see a significant decrease in energy bills).
Conclusion
The Sun is here for all of us, and has enough potential to produce electricity and heat for all the people living on this planet.
The quicker you will start using solar power at home or for your company, you will start protecting nature and your wallet because beside lower energy bills, you will also reduce your carbon footprint.
