Renewable energy represents today the sources of power that will never end, which means that mankind will rely on these green sources of power when fossil fuels will be depleted.
The sources of energy that never end (endless sources of power) are not controlled by mankind, they are mostly provided by nature itself, which means that they are clean and also free to be harvested and used by anyone on the planet.
What is Renewable Energy?
Renewable energy is represented by the power sources provided by the Sun, the Earth’s core, the gravitational forces of the Sun, Moon and Earth combined, and by the environment on planet Earth.
Being provided by external sources of energy (external to our planet), renewable energy is the perfect candidate to replace the dirty fossil fuels in a not so far future.
It seems that mankind needs to burn all the dead plants and animals that lived tens of millions of years ago here on the planet, before understanding that we don’t need to destroy the environment while producing energy, because free and clean energy is available on the planet way before the apparition of mankind.
How Clean is Renewable Energy?
Renewable energy is the energy provided by the renewable resources available on the planet such as sunlight, wind, water, wood, waves, tides, geothermal heat, which are renewed all the time, but are not necessarily clean.
It is true that most of the renewable resources are 100% clean, but there are a few that produce some harmful emissions while burning to generate heat and electricity.
Sunlight, wind, water, waves and tides are 100% clean because they produce energy without releasing harmful emissions into the atmosphere, but biomass (wood) and geothermal power are slightly different.
Biomass is represented today by wood mostly, but also plant and crops waste, energy crops, human and animal organic waste, trash, etc.
When we burn biomass to produce heat or steam that will spin a turbine to generate electricity, some emissions are released into the atmosphere.
Wood that is burned in stoves for heating and cooking also releases harmful emissions into the atmosphere, which means that biomass (mostly wood) is only a low-carbon resource, not a clean one.
Geothermal energy is provided by the Earth’s internal heat (our planet’s core is hotter than the surface of the Sun), and when it reaches the surface under the form of hot water and steam, some greenhouse gasses located in the underground can also migrate to the surface to be released into the atmosphere along with the natural resource of hot steam and water.
The hot water that comes from the underground can also contain traces of toxic heavy metals such as mercury, arsenic and boron.
Renewable Energy Resources that are 100% Clean
I already mentioned that renewable energy means energy which is renewed all the time, but is not 100% clean.
Let’s see what resources of renewable energy are 100% clean.
1. Sunlight
The Sun is the main resource of renewable energy on planet Earth because it is behind several resources of renewable energy that are 100% clean.
One of these renewable resources that are 100% clean is represented by the sunlight.
We are using the sunlight today to generate clean electricity and hot water.
Mankind uses solar panels to turn the sunlight into clean electricity (solar power) or large mirrors that are pointed towards the top of a tower where molted salt or another agent is heated at high temperatures to produce steam which will spin a turbine to generate clean electricity (solar thermal power).
The sunlight is also used to heat water with the help of an agent (a special oil) that is heated by the Sun and reaching high temperatures, which will then be used to produce hot water for free.
Passively, the sunlight is used to light and heat the rooms of a house (the building is positioned is such a way to allow the sunlight to enter the rooms), which will significantly lower the energy bills.
2. Wind
The wind on our planet is also produced by the Sun.
Our star is heating the different layers of air in the atmosphere in an uneven way, which makes the warm air to rise and the colder air to go down.
This movement of the air layers in the atmosphere is actually the wind.
We are using today large wind turbines mounted onshore and offshore to harvest the kinetic power of the wind and turn it into clean electricity.
There are also residential wind turbines that are smaller (lately vertical residential wind turbines have become more popular) and are used by homeowners to generate some clean electricity and lower their energy bills.
The vertical wind turbines are more practical, less noisy and they are also friendly with the wildlife in the area (they are not killing birds and bats due to their design).
3. Water
Water on planet Earth is another great renewable resource that is also 100% clean.
Fast moving water or the falling water is used today to generate hydroelectric power, which is 100% clean electricity.
Underwater turbines are spinning under the action of the moving water and they produce clean electricity using large generators.
Hydroelectric power or simply hydropower is the power of the water (a renewable resource) and is 100% clean.
Hydroelectric power is produced today on a large scale all over the planet, and this is the reason why hydropwer has the highest share among all renewables in the energy mix of the U.S.
4. Waves
The waves in our oceans represent another renewable resource available for us to generate clean electricity.
Wave power is in its infancy today, but there are companies that have improved the technology, and now we can harvest the kinetic power of the waves using specially created buoys.
Compared to the other clean renewable energy resources, wave energy is more stable and more predictable.
5. Tides
The tides on our planet are produced by the combined gravitational forces of the Sun, Moon and Earth acting on the water in our oceans.
The tides are also stable and predictable, and they are using robust underwater turbines with a special design (a large hole in the middle of the turbine to allow the sea life to escape from the rotating turbine).
The techology used to generate tidal power is quite young today, because we are producing tidal energy (which is 100% clean) only in a few locations on the planet where the tides are high enough.
However, when the technology used to harvest the tremendous power of the tides in our oceans will be improved, we will be able to generate tidal energy all over the planet.
Low-Carbon Renewable Energy Resources
I mentioned above that wood (biomass) and geothermal power represent low-carbon renewable resources because they can release some harmful emissions into the atmosphere.
1. Wood as Biomass
Wood is the main natural material used by biomass energy today.
Wood, agricultural waste and energy crops are all used to generate biomass energy under the form of heat (for residential heating and cooking) and steam that is then used to spin turbines and generate clean electricity.
When burns, the wood releases some harmful emissions into the atmosphere (less emissions than coal, oil or natural gas), and this is the reason why wood (and biomass) is considered a low-carbon renewable energy resource.
2. Geothermal Energy
Geothermal energy as resource of renewable energy is available in several countries on the planet.
Iceland is a country where geothermal energy is used on a large scale in the country for residential heating and cooling, but also to produce clean electricity.
In Iceland, the hot water that flows through all the faucets is coming from the underground source of geothermal energy, and is available day and night.
To generate clean electricity, we are using the hot steam provided by the geothermal resource, which will spin turbines that are producing electricity with the help of generators.
When is used for electricity generation, geothermal energy is 100% clean, but this natural resource can release harmful gases in our atmosphere only when is harvested directly from the underground.
Harmful gases can travel along with the resource (hot water and steam) up to the surface to be released into the atmosphere, and this is the reason why geothermal is considered a low-carbon resource of renewable energy.
Conclusion
The resources of renewable energy available today on the planet (both low-carbon and 100% clean), can be considered future sources of energy that will power the future generations of people.
