First and Second Laws of Thermodynamics

The first law of thermodynamics is mainly concerned with energy conservation and it states that energy cannot be created or destroyed. However, energy can be converted from one form to another. The total amount of energy entering into a system must be equal to the equal to the total amount of energy that is leaving the system (Toja-Silva & Rovira, 2014). Energy can be transformed and transferred but it must always remain constant.
The second law of thermodynamics is entropy. Entropy is the measure of change from order to disorder. Matter will move from an area of high concentration to an area of lower concentration. The law states that entropy of an isolated system that is not in thermal equilibrium will increase to a point of equilibrium (Toja-Silva & Rovira, 2014). It is not possible for heat to emanate from a cold object to a warm object without work. In essence, an object that is cold cannot make another object warm naturally.
Energy remains constant because it cannot be created or destroyed. The first law mainly covers the conservation of energy and its transformation from form to another. However, something does change in the energy conversion and that is its re-usability. Anytime there is an energy conversion there is some energy that becomes less useful and eventually, all the energy will become less useful. This is mainly in as far as the ability of energy to make things happen is concerned. Therefore, the more energy that is used the more low-grade energy is available. Low-grade energy is only useful for warming the air around us and it cannot be used to do things that are considered useful. With energy efficiency, we would be able to reduce the amount of low-grade energy. Thus, ensuring that we are not overusing the currently available energy.
Pros and Cons
Fossil Fuel: Oil, natural gas, and coal
Fossil fuels are cheap and reliable sources of energy because they are extracted from the earth in large quantities. They are also reliable as they are not affected by external environmental factors, which make them a safer option for large power generation companies. Fossil fuels are efficient when compared to other energy sources. The cons of fossil fuels are they are not friendly to the environment because when they are burnt they produce carbon dioxide and other harmful gases (Ellabban, Abu-Rub, & Blaabjerg, 2014). They also contribute towards climate change and global warming. Fossil fuels are not renewable meaning that a time will come when the earth's fossil fuel deposits will be completely used up.
Nuclear Energy
Low pollution is on the pros for nuclear energy. Nuclear energy has fewer greenhouse gases emissions. Low operating costs since the lifespan of a nuclear reactor is anywhere between 40-60 years. Nuclear energy is more reliable than solar and wind, meaning it can run without any disruptions in any climatic condition. The energy produced is greater than the amount produced when using fossil fuels (Toja-Silva & Rovira, 2014). Some of the cons for nuclear energy are the radioactive waste produced can be a threat to the environment and it is dangerous for humans. The setup costs for a nuclear reactor are too high, which makes it less desirable to invest in. Uranium that is used to create nuclear energy is finite and it only exists in few countries. It is also expensive to mine, refine, and transport uranium.
Solar Energy
The pros for solar energy is that it is a sustainable source of energy and a good alternative to fossil fuels. Solar energy is renewable meaning we cannot run out of solar energy. It is the most abundant source of energy on earth. Solar energy is also sustainable in that is meets our current needs and it does not impact future generations ability to meet their energy needs. Reduces the costs of electricity and it is environmentally friendly. The cons for solar energy are that it is expensive to purchase solar panels and storage of this energy is also expensive. It is also intermittent because it is limited to certain times and on overcast days it might be unreliable.
Wind Power
Wind power has enormous potential and it can be done almost anywhere. It is also renewable because wind is naturally occurring and we cannot empty the energy resources of wind (Ellabban et al., 2014). There are low operating costs since once installed the turbines do not need much maintenance. The cons for wind power are its unpredictability because the wind might not be constant. However, if there were cost-effective ways of storing this energy then the situation could be different. The costs of purchasing and installing the wind turbines can be prohibitive. There is a lot of noise pollution. The turbines are also a threat to birds, bats, and other flying creatures.
Water (hydro) Power
Water (hydro) power is a reliable source of energy and it is used as a base source for energy. This source of energy is renewable meaning that we cannot use it up. It is also easy to adjust the flow of water for peak and off-peak times. The cons for hydropower are the effects it has on the environment in terms of redirecting water, changing the flow of water, and power lines construction. When there is drought the water levels will decrease and this will impact energy generation. There are limited reservoirs for hydropower generation.
Algae Fuel Source
Algae produce oil that can be converted into biofuel, and they can produce more oil than land-based plants. The oil produced can be extracted in order to produce fuel for anything that runs on gasoline. Algae make use of carbon dioxide for it to grow and this is beneficial to the environment because algae will be taking carbon monoxide out of the atmosphere (Ellabban et al., 2014). This characteristic also makes algae a carbon neutral fuel source. There might also be potential to use carbon dioxide fumes from other power sources to fuel the growth of algae. Since algae make use of carbon dioxide it is environmentally friendly and has no negative effect on the environment when it is produced and converted into energy. Another characteristic of algae is that the carbon dioxide produced when it is burned is what the algae have consumed as food meaning that the emission is same as if the algae had not been grown.
The pros for algae are that it is beneficial to the environment as compared to the other fuels sources. This is because it consumes carbon dioxide. There are numerous byproducts that are produced during its oil extraction and conversion. This is not possible with other oil extraction processes. There are also abundant resources of algae with some species being able to double in number in just a day, which would make oil production something not to worry about.


References
Ellabban, O., Abu-Rub, H., & Blaabjerg, F. (2014). Renewable energy resources: Current status, future prospects and their enabling technology. Renewable and Sustainable Energy Reviews, 39, 748-764.
Toja-Silva, F., & Rovira, A. (2014). A first and second thermodynamics law analysis of a hydrogen-fueled microgas turbine for combined heat and power generation. Journal of Engineering for Gas Turbines and Power, 136(2), 021501.