Thermodynamics and alternative energy

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Thermodynamics and alternative energy

The laws of thermodynamics

The zeroth law of thermodynamics states that if two systems are both in thermal equilibrium with a third system, then they are in thermal equilibrium with each other. This law allows for definition of the empirical temperature as a system property (Boundless, undated). Hence, if system 1 has the same temperature as system 2 and system 2 has the same temperature as system 3, then the temperature of system 1 is the same as that of system 3. Three systems that are in thermal equilibrium have the same temperature, with the law allowing for definition of empirical temperature.

The first law of thermodynamics states that energy cannot be created or destroyed; it can only be changed from one form to another form or transferred. For example, kinetic energy in wind changes to mechanical energy and then to electrical energy. This first law of thermodynamics is also known as the law of conservation of energy (Cengel and Boles 2014).

The second law of thermodynamics states that an isolated system’s entropy always increases. This is because isolated systems, systems that neither matter nor energy can pass through because of the enclosing boundaries, naturally evolve towards thermal equilibrium. By achieving thermal equilibrium, the system achieves maximum entropy. Notably, isolated system is hypothetical for calculations only, since they do not really exist (Cengel and Boles 2014). However, the universe is defined as an isolated system, with its entropy always increasing.

The third law of thermodynamics states that as a system’s temperature approaches absolute zero, the system’s entropy approaches a constant value. This means that there is typically no entropy in a system with 0 K temperatures, though residual entropy based on the ground state of the system may exist (Boundless, undated).

Thermodynamic laws versus energy use, conversion and efficiency

Work and heat usually happen when energy is captured while moving from an area of high concentration to an area of low concentration, the unstoppable tendency of energy. However, in certain circumstances such as compressed gas and photosynthesis, the energy flow is reversed.

One way to ensure most energy is channeled towards work is increasing thermal efficiency (Cengel and Boles 2014). This is achieved by noting where energy dispensed by a system ends up. Then a system’s conversion of energy into useless energy (e.g. thermal energy from an engine) is reduced whereas conversion into useful energy (e.g. mechanical energy) is increased.

While energy does not get used up, its availability reduces. Hence we should be energy efficient, aiming towards the unattainable 100% energy efficiency, by reducing the number of conversions energy goes through (Boundless, undated). Thus if kinetic energy can be directly converted to electrical energy there is no need for it to go through mechanical energy form if all other factors are constant.
Pros and cons of various energy types
The nonrenewable fossil fuels are abundant, easily accessible and inexpensive. They provide a lot of concentrated energy at relatively low cost e.g. gas is very energy efficient. Crude oil and refined oil can easily be transported from where it is extracted or to where it is needed using pipes. The main disadvantage of fossil fuels is pollution (DeGunther, 2009). The pollution is experienced through global warming (greenhouse effect), oil spills, odor and acid rain. Mining of fossil fuel also leads to land destruction.

The multi-step process of nuclear power stations improves energy efficiency while suppressing the many negative byproducts of nuclear energy. Nuclear energy is more reliable than other forms of energy, with a capacity to run for 540 uninterrupted days (DeGunther, 2009). Compared to fossil fuels, this energy is less expensive to get and transport and its plants does not emit greenhouse gases. However, uranium is a naturally unstable element that must be carefully handled to avoid radiation. The radioactive nuclear byproducts can also lead to contamination and pollution, with heated water from nuclear plants adversely affecting the ecosystem.  Abandoned nuclear reactors also pose a huge challenge since they cannot be removed yet take up valuable space.

Solar energy is a silent, renewable, clean energy until when the sun runs out in several billion years’ time as predicted (DeGunther, 2009). This makes its use get good tax credits from the federal government. Solar panels also require little maintenance with largely reliable mechanical parts. Nonetheless, installation of solar panels can be expensive albeit the free energy. Yet, conversion of sun rays to energy is quite inefficient although new technology is improving this. A major disadvantage is the reduced performance of solar panels during cloudy days and at night though new technology is gradually improving the capacity to store solar energy.

Wind is free and is energy efficient. This renewable energy does not cause pollution, although manufacture of wind turbines does cause some pollution. Wind turbines also do not ‘ debatable with some arguing that the turbines are unsightly) coexisting with other activities e.g. farming (DeGunther, 2009). Just like solar panels, the turbines are in different sizes to fit different requirements and budgets and can be installed independently of the power grid to serve remote areas. Usually, the bigger the turbine, the noisier it is. Wind strength is also inconsistent and the turbine may not produce power in certain instances. The increased frequency of hurricanes and cyclones has also raised a safety concern of wind energy.
Hydropower is a clean, renewable energy that does not pollute the environment. Unlike wind power, hydropower is available when needed. Apart from providing energy, the water reservoirs are important for supplying water (e.g. for irrigation) and controlling flooding. They can also be used for recreational purposes such as fishing, swimming and sightseeing. However, hydropower plants can easily be impacted by droughts. They also affect the riparian communities by affecting water quality, water flow and land use. Fish populations may also be affected to the impact on fish migration. Construction of hydropower plants is also relatively expensive and can lead to environmental damage e.g. earthquakes caused by Hoover Dam.

Biofuels are a renewable energy with less greenhouse gases compared to fossil fuels, with some estimating a 65% reduction. This energy is easily available being got from plants, crop waste or manure (DeGunther, 2009). Biofuels enhance a country’s economic security because of less dependence on imported oil. However, producing biofuels is costly and fertilizers lead to water pollution. It may also lead to monoculture and consequent soil degradation.  
Energy Policy Act of 2005
The Energy Policy Act of 2005 aims to curb problems posed by the need for more energy by improving supply. One provision is authorizing tax credits for producers of alternative energy (USCHR, 2005). This excludes fossil fuels but includes all the other energies including nuclear energy. It especially rewards producers of clean, renewable energy.

Because of this provision, there has been increasing market adaption, investment and job creation in alternative energy because of decreased pay-off time. Academic, commercial and government sectors are conducting advanced research in this field with a view to improving energy efficiency and increasing total energy production ((BOEM, undated).

The Production Tax Credit (PTC) reduces the federal income tax paid by alternative energy projects that connect to the power grid, the Investment Tax Credit (ITC) reduces federal income tax paid by those who invest on alternative energy projects, and the Advanced Energy Manufacturing Tax Credit (MTC) awards tax credits to facilities that advance clean energy.

Sandia National Laboratories and the National Renewable Energy Laboratory (NREL) funded and supported by the Department of Energy and corporations are two prominent organizations in alternative energy. As a result of the research and adoption of alternative energies such systems as the Plug-in Hybrid Electric Vehicles (PHEV) are on the rise (BOEM, undated).

Another provision of the Energy Policy Act is authorization of the Department of the Interior to grant leases for energy production, transportation or transmission on the Outer Continental Shelf lands from sources other than fossil fuels (USCHR, 2005). This has led to initiation of development of offshore facilities (notably in the Gulf of Mexico) for alternative fuels – especially wind, wave and ocean current technologies. When these developments become fully operational, they will contribute much clean energy to the power grid. They will also increase adaption of components and systems that use alternative energy. Moreover it will increase United States’ security, independence and health due to less reliance on foreign fossil fuel.

References

BOEM. (undated). Guide to the OCS Alternative Energy Final Programmatic Environmental Impact Statement. http://www.boem.gov/Renewable-Energy-Program/Regulatory-Information/Guide-To-EIS.aspx. Accessed on August 1, 2016.


Cengel, Y. and Boles, M. (2014). Thermodynamics: An Engineering Approach 8th Edition. New York: McGraw-Hill Education.

DeGunther, R. (2009). Alternative Energy for Dummies. New York: Wiley.


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