The first law of thermodynamics Essay
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The first law of thermodynamics states that energy can neither be created nor destroyed; it can only be converted from one form to another. This can be illustrated using the example of steam power. Thermal energy is stored in steam. This steam can be used to drive an steam engine which converts this thermal energy in the steam into kinetic energy of the unit (say steam driven train). In thermal power plants, fossil fuel is burnt to produce steam and the thermal energy in the steam then drives the turbine to produced electricity.
Thus thermal energy of the steam gets converted into electrical energy. From these two illustrations it becomes obvious that energy can neither be created nor destroyed it can only be converted from one form to another. Three types of non-renewable power plants and the fuel consumed by these power plants are listed below. Fuels cells use the electrons produced in a chemical reactions to produce electricity. One example is Hydrogen – Oxygen Fuel cell.
In this case Hydrogen is oxidized at anode into hydrogen ions plus electrons and oxygen is reduced at cathode into oxide ions at cathode. Anode and cathode is separated by solid electrolytes and connected by a metallic wire. The electrons move from anode to the cathode through the metallic wire and thus electricity is produced. This is very clean source of electrical energy. Criteria for acceptability of energy alternatives are listed below.
Technological feasibility – It should be technologically feasible to convert the energy into usable forms like electricity etc. Abundance – The energy source should be available in abundance. Reliability – The energy source should be reliable. This is particularly relevant for wind energy and solar energy in the regions of unpredictable sky conditions and wind conditions. Capital Expenditure – Generally capital expenditure requirements are high and act as major barrier for exploiting renewable energy sources.