Sustainability is the “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Bruntland Report for the World Commission on Environment and Development (1992)
As you read this from your computer, phone, or iPad, note that you’re burning fossil fuels to provide the energy your devices need to work. The energy we use mostly comes from nonrenewable sources (limited and can run out) such as coal, oil, or gas. Their creation comes from the remainings of living organisms such as plants, over the span of several millions of years. They contain carbon dioxide that these living organisms once absorbed from the atmosphere through photosynthesis. When burned, they return that carbon dioxide to our atmosphere, acting like a huge blanket that traps the heat coming from the sun. As a result, global warming and its chain reaction are leading our World to climate change, transforming our environment and our lives.
To create a sustainable World is to find other types of energy that are renewable and inexhaustible, without harming our planet. These energy sources represent the so-called clean energy, which means that we can use them as much as we want without increasing our carbon footprint.
What type of clean energy can we use?
Besides having an important role in other types of renewable energy, the most direct use occurs when photovoltaic systems capture the sun’s energy to convert it into energy. It can provide us with warm water by the circulation of water through flat-plate solar collectors. The sun’s heat can also concentrate on mirror-covered dishes. As a result, water boils from a conventional steam generator and produces electricity. Solar power can be used by purchasing it from offsite commercial solar installations; constructing buildings that include solar hot water, ventilation or cooling systems; and by installing solar panels on the rooftops.
Winds are formed by the combination of unequal heating and cooling of the atmosphere by the sun with the rotation of the earth (and other topographical factors). Large turbines can capture wind flow and convert it into electricity – creating eolic energy. When a great number of wind turbines are built in the same area, they are referred to as a wind farm. Wind farms work as a single power plant. They send electricity to the grid and once it’s there, electric corporations will send the electricity to our homes.
Energy generated by water is known as hydroelectric power. It’s the result of the construction of a dam that stores great amounts of water in a reservoir. When the water is released, it flows through turbines that produce energy. However, some hydroelectric power plants don’t necessarily require a dam. They can work the same way through a small canal that channels the water through a turbine. While the turbines spin, they activate generators that produce electricity.
Two types of energy can be provided by the ocean: mechanical energy created by the movement of waves and tides or thermal energy from the sun’s heat. Ocean waves create energy when waves rise into a chamber, forcing the air to leave and spin a turbine which then turns a generator. Tidal energy is produced when large turbines are placed underwater and in areas with high tidal movements. These turbines then capture tides motion and create energy. Ocean thermal energy conversion works by using the different temperatures existing between shallow and deep waters. This is possible by using an ocean thermal energy conversion plant. It pumps large amounts of shallow warm seawater and deep cold seawater to run a cycle that produces electricity. This method is more efficient when the difference between temperatures is greater.
At the moment, generating clean energy from the ocean is rare. There are only a few ocean energy power plants, most of them really small and unable to create energy on a global scale. As our oceans cover more than 70% of the planet, they are capable of providing us the energy we need. There’s a need for more studies and attention to this renewable energy sector.
Known as geothermal energy, it is when energy is created from the heat of the earth. It can derive from hot water located deep on the ground or from heated rocks. Geothermal power plants trap this heat to produce electricity. We can use this type of energy in the commercial sector such as aquaculture, greenhouses, and office buildings.
Hydrogen is the most abundant element in the universe, found in natural gas, methanol, propane gasoline and water, although it doesn’t occur naturally. Being an element with high levels of energy and producing almost no pollution when burned, hydrogen produces energy by releasing only pure drinkable water and heat. NASA has been using this element since the 1970s to take their gadgets into space. This is possible when the hydrogen fuel cells give power to the electrical systems. We can also use it to provide emergency electricity to buildings and remote locations or to fuel marine vessels.
Biomass refers to organic matter that came from recent living animals or plants. The use of biomass as renewable energy to create heat and electricity represents bioenergy. When burning biomass, roughly the same amount of carbon dioxide goes to the atmosphere, as when burning fossil fuels. However, plants are replaced to absorb that same quantity of carbon dioxide, creating a relatively neutral impact. Using biomass reduces the need for fossil fuels. Research is still needed to make this energy source more efficient.
There are plenty of solutions available that can provide us with renewable energy, without putting our future and planet in danger. As the global population grows, we have reached the point where we need more energy than ever before. Yet, less than 10% of all energy comes from renewable sources, mostly because of their high cost. To evolve our society into clean energy, we must find solutions to improve their efficiency and provide them to everyone at an affordable cost. When this happens, we can be sure we will be living in a sustainable World.