Solar Energy – The Energy of The Future

We have seen and experienced directly or indirectly the effects of global warming on our world. In this article, we will first look at how we are causing this through the way we produce energy, which is by burning fossil fuels. And then, we will look at all the energy sources that are candidates for replacing fossil fuels and compare their advantages and disadvantages. Lastly, we will look at solar power and the reasons why we think that solar energy will be the energy of the future.

Causes of Climate Change

The Slow and Fast Carbon Cycles

There are two types of Carbon Cycles, the slow and fast carbon cycles.

The slow carbon cycle is the slow process of carbon moving from the rocks to the soil, to the ocean and finally, to the atmosphere. This is a very slow process that releases 10^13 to 10^14 grams (10–100 million metric tons) of carbon to the atmosphere every year.

The fast carbon cycle, on the other hand, is the movement of carbon through the life forms on Earth and finally to the atmosphere. It releases up to three orders of magnitude of carbon more (or 1,000 times more) in the atmosphere, at 10^15 to 10^17grams per year.

All the lifeforms here on Earth are Carbon-based. All living cells are formed from long carbon chains and rings. Even the DNA, which is called “the blueprint of life” is made of two intertwined molecules built around a carbon chain. Most importantly, the sugar which we get from the food that we eat is also made up of long carbon chains. When carbon forms these long chains, energy is stored. This way, sugar acts as the main source of energy for all living organisms on Earth.

The main components of the fast carbon cycle are the plants. They inhale carbon dioxide and use this, along with water and the energy from sunlight to form sugar. This is the main ingredient used to grow new body tissues. In the process, they also produce oxygen as waste, which is exhaled to the atmosphere.

Plantlife is such a big part of the carbon cycle such that during spring in the northern hemisphere, carbon dioxide concentrations in the atmosphere drop. This is because increased demand for carbon dioxide by the growing plants. During winter, when plants are dying and decaying, carbon dioxide concentrations in the atmosphere rise as decaying plants release the carbon stored in their bodies as carbon dioxide. This rising and falling of carbon dioxide make it seem that the Earth itself is breathing in sync with the pattern in which plants grow and die.

Humans and animals eat plants and use the sugar for energy. When this sugar is burned, the carbon combines with inhaled oxygen to form carbon dioxide, which is then released to the atmosphere, completing the carbon cycle.

Naturally, the slow and fast carbon cycles are balanced in a way to keep carbon dioxide concentrations in the atmosphere constant to trap just the right amount of heat. But since the industrial revolution, we have disturbed the carbon cycle by burning fossil fuels for energy. These fossil fuels contain the carbon from plant and animal life that took millions of years to accumulate. Without human intervention, the carbon in these should have been slowly released in the atmosphere through the slow carbon cycle. However, by burning them, we speed up this process, significantly increasing the rate at which carbon dioxide is released to the atmosphere.

Why Focus on Carbon Dioxide?

Carbon dioxide has had the biggest contribution to global warming than any other greenhouse gas. This is because of the sheer amount of it that we are dumping on the atmosphere by burning fossil fuels for energy. It comprises a total of 76% of our total greenhouse gas emissions including those that are emitted through land use (deforestation and land clearing for agriculture). 65% of those are from burning fossil fuels.

Source: IPCC (2014); based on global emissions from 2010. Details about the sources included in these estimates can be found in the Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.

At the global scale, the key greenhouse gases emitted by human activities are:

• Carbon dioxide (CO2): Fossil fuel use is the primary source of CO2. CO2 can also be emitted from direct human-induced impacts on forestry and other land use, such as through deforestation, land clearing for agriculture, and degradation of soils. Likewise, land can also remove CO2 from the atmosphere through reforestation, improvement of soils, and other activities.

• Methane (CH4): Agricultural activities, waste management, energy use, and biomass burning all contribute to CH4 emissions.

• Nitrous oxide (N2O): Agricultural activities, such as fertilizer use, are the primary source of N2O emissions. Fossil fuel combustion also generates N2O.

• Fluorinated gases (F-gases): Industrial processes, refrigeration, and the use of a variety of consumer products contribute to emissions of F-gases, which include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6).

It is very clear from these data that the main cause of climate change is our carbon dioxide emissions from burning fossil fuels. This makes the world’s shift to a cleaner and better energy source all the more inevitable. This also puts solar energy at the forefront of the choices of being the energy of the future.

Nuclear Energy

Nuclear and renewable energy are the principal competitors for low-carbon electricity in most countries. There even have been many debates on which of the two will become the energy of the future, even though, not including China, most nations have been moving away from nuclear energy.

Nuclear energy is the energy in the nucleus or core of an atom. There are two ways on how nuclear energy is released: fusion and fission. In nuclear fusion, atoms combine to form larger atoms while in fission, atoms are split apart. Today’s nuclear power plants utilize fission to produce nuclear energy as this is easier, safer and more reliable.

The process of creating nuclear energy from fission is as follows:

• Nuclear reactors force some Uranium atoms to break apart.

• As these Uranium atoms split, they release particles called fission products.

• These fission products collide into other Uranium atoms, causing them to also split. This starts a chain reaction until all of the Uranium atoms are split apart.

• This process releases a large amount of heat, which is then used to boil water and drive a turbine.

Advantages of Nuclear Energy:

• Less amount of fuel needed for the same amount of energy – this translates to lower production, and procurement and transportation costs.

• It is more reliable – a well maintained nuclear plant can run uninterrupted by as much as 540 days.

• No greenhouse gas emissions.

Disadvantages of Nuclear Energy:

• Radioactive material – the fuel used in nuclear energy is Uranium, which is radioactive. This means that special precautions must be made during mining, transportation and storing it, as well as disposal of the waste materials from nuclear reactors because these can also give off harmful levels of radiation.

• Water pollution – water is used to cool the nuclear fission chambers. Although water does not directly become in contact with the reactor, there is still a possibility of a fuel leak that can contaminate the water. Also, the water will still be warm when released back into its source, which disrupts the local ecosystem.

• Radiation leaks – improperly installed and/or maintained nuclear power plants can release harmful amounts of deadly radiation into the environment.