Solar power is a green energy source generated by the Sun.
Green energy is considered today the source of clean power that will replace the dirty energy generated by fossil fuels for a future without pollution.
In recent decades, mankind started to understand that we can’t continue burning fossil fuels (coal, oil, natural gas and nuclear) for energy generation, mostly because these are finite sources of power and they also create a massive pollution on the planet.
Searching for alternative sources of power (that can replace the fossil fuels), scientists discovered that the natural sources of energy available on the planet can be used to generate green energy, which is friendly with the environment and is also sustainable.
Green energy represents all the clean sources of power that are generated using the natural source of energy available on the planet, which are friendly with environment releasing zero emissions and are also renewable.
The green sources of power on planet Earth are produced by nature or by the Sun, so they are renewable and sustainable because they never run out.
Examples of Green Energy
Being produced by the Sun or by our planet, the green sources of energy available today are produced continuously so it is obvious that until we have the Sun and the planet we have multiple sources of clean power at our disposal to generate our own electricity for free.
1. Solar power
The Sun represents a continuous source of heat, light and energy for us and is here way before the apparition of mankind on the planet.
The Sun will continue to send light, heat and free energy towards us for another 5 billion years, so we can say that solar power is a renewable source of energy.
The power of the Sun is used today to passively heat homes, which will generate very small energy bills for the owners during the winter.
The sunlight is also used actively to produce clean electricity with the help of solar cells, or as a heat source for water or another agent (molten salt) that will generate steam, which will be then used to spin a turbine and produce clean electricity.
The Sun is actually the main source of clean power available in the Solar System, at least for the first four planets (Mercury, Venus, Earth and Mars) that are located pretty close to the Sun to feel its presence.
The Sun is also the source of the wind and one of the celestial sources that are producing the tides, which means that the Sun is responsible for several sources of clean power available on the planet.
I already mentioned that the Sun is the source of the wind on planet Earth.
Because the Sun heats the layers of air in our atmosphere in an uneven way, the layers of warm air will move up in the atmosphere and the colder layers of air will move down, and this is the wind on the planet.
The kinetic power of the wind can be used to spin large turbines at low speed.
The low rotational speed of the turbine will be increased about 100 times using the gearbox located inside the nacelle of the wind turbine and the high rotational speed of the shaft obtained this way will be used to generate clean electricity with the help of a large generator.
Today, wind power generated by large wind farms located onshore and offshore are already feeding the grid with clean electricity, but because wind and solar power are clean but intermittent sources of energy we are also using the energy produced by natural gas or another fossil fuel to ensure a continuous source of electricity for the grid (fossil energy combined with clean energy).
Wind power is another form of green energy because is renewable (is produced every day by the Sun) and is also sustainable and clean (releases no harmful emissions).
Hydroelectric power is the green energy source that has the highest share among renewables in the energy mix of the planet.
Hydroelectric power or simply hydropower represents today a cheap and pretty old source of clean electricity available on the planet that is produced using the kinetic power of the falling water, which is used to spin underwater turbines that will produce clean electricity with the help of generators (large dams).
The force that makes the water to fall is called gravity and is a continuous and pretty constant force that is produced by Earth’s rotation.
The kinetic power of the falling water is much higher than the kinetic power of the wind, which means that the underwater turbines used to generate clean electricity will be smaller, but more robust than wind turbines.
Moving water represents a great source of green energy on planet Earth.
Tidal energy is another form of green power that also uses the power of the water, but in this case we are talking about the kinetic power of the tides.
The tides on planet Earth are created by the combined gravitational forces of the Sun, the Moon and our planet, which means that tidal power is a renewable energy source and is also green because is friendly with the environment (zero emissions).
There are only a few places on the planet where the tides are strong enough to be used as a green energy source.
The underwater turbine used to generate tidal energy is smaller but more robust than a wind turbine and features a large hole in its center to allow the marine life to escape from the rotating turbine.
Wave power is another form of green energy that uses the kinetic power of the water to produce clean electricity.
The waves are produced by the wind that passes over the surface of the seawater, and this movement of the water is used today to generate clean electricity, to desalinate seawater or to pump water.
The wind is produced by the Sun, which means that wave power is a renewable energy source, and is also green because releases no harmful emissions into the atmosphere.
Biomass consists today of wood, plant waste, municipal solid waste, biofuel such as ethanol and biodiesel, biogas and landfill gas, animal waste, but also different forms of trash produced by people.
Biomass is used today to generate clean electricity, but also for heating and cooking.
To generate clean electricity, biomass is burned to generate steam that is then used to spin a turbine and produce clean electricity with the help of a generator.
Biomass energy releases some forms of emissions, but is a cleaner source than coal, oil or natural gas.
Because wood, organic waste and trash is produced every day, we can say that biomass energy is considered a renewable resource.
It is also partially green because releases less emissions than conventional fossil fuels.
Geothermal energy is generated by the heat of the inner core of our planet and reaches the surface of the planet under the form of hot water and steam.
The inner core of our planet is very hot (even hotter than the surface of the Sun) reaching a temperature of 10,800 °F (6,000 °C).
This natural heat the reaches the surface in a few places on the planet can be used to generate clean electricity, and for residential heating and cooling.
In several countries on the planet (the U.S., Iceland, New Zealand, Philippines, Indonesia, Mexico, Italy, Japan, Kenya, Iran, El Salvador, Nicaragua and Costa Rica) geothermal energy represents a powerful natural resource, and also a great economic asset for these countries.
Being produced by the heat released by the inner core of our planet, geothermal energy is considered a renewable energy source that will last as long as the planet will exist, and is also a green energy source because releases no harmful emissions into the atmosphere.
Green energy represents a great asset for our planet because it can be used to generate clean electricity and heat without polluting the environment.
The technology used today to harness the sources of green power available on the planet have low efficiency, and this is the reason why we need to wait a few more decades until technology will improve to generate much more clean energy than today.
We can’t stop burning fossil fuels even if we know that we are polluting the environment until we don’t have a viable source of green power that can cover the entire demand of electricity on the planet.
Luckily, a large number of scientists are involved today in the research and development of new sources of clean and sustainable power, which means that fossil fuels will no longer be here for a long time to pollute the environment.
The future is green, renewable and also sustainable, which means that the future generations will inherit from us an environment that is healing after more than a century of heavy pollution of the air, water and soil.
Mankind can survive on planet Earth only if the environment is preserved and we are using only green energy sources to cover our electricity demand.
I am a writer and reporter for the clean energy sector, I cover climate change issues, new clean technologies, sustainability and green cars.