In order for the energy requirements of the future to be met, an unprecedented development of new energy harvesting technologies to replace simple exothermic oxidation is absolutely essential. An imminent large-scale development and implementation of new energy harvesting technologies is vital for a number of reasons. Foremost amongst them are the facts that the burning of fossil fuels (natural gas, coal and oil), the most common way in which exothermic oxidation is used as an energy source, contributes heavily to air pollution and degrades the environment, mainly through contributing to global warming, and causing acid rain. Additionally, fossil fuels are a finite source of energy, with current reserves are expected to last 40-70 years.
Fossil fuel combustion is estimated to contribute to over ninety percent of the world’s gross greenhouse gas, gaseous components of the atmosphere that contribute to the greenhouse effect’, emissions. Largely due to these greenhouse gas emissions, global temperatures are projected to rise by an average of about three degrees Celsius by 2100. Such a temperature increase would be likely to result in rising sea levels, and subsequent recurrent flooding, mass extinction, with many animals unable to adapt to suit the warm conditions quickly enough, the spread of mosquito-transmitted diseases, such as malaria and dengue fever, since mosquitoes lay their eggs in water, the increased occurrence of devastating storms, as warm oceans are a critical ingredient in hurricane formation, and more. Clearly, it behooves society to reduce the utilisation of the exothermic oxidation of fossil fuels as a means of generating electricity, and through that, reduce greenhouse gas emissions.
Another environmental problem caused by the combustion of fossil fuels is acid rain. The burning of fossil fuels emits sulpher dioxide and nitrogen oxides, which then combine with atmospheric moisture, forming pollutants such as sulphuric acid, ammonium nitrate and nitric acid. Acid rain causes many problems, among which are the facts that it acidifies lakes, preventing them from supporting the same variety of life as healthy lakes, harms vegetation by reducing its vitality and capacity for regeneration and causing soil to lose nutrients, and erodes marble statues.
Yet another reason as to why it is the development of new energy harvesting technologies is essential is that fossil fuels are not a renewable source of energy, with current reserves expected to last approximately seventy years if the present rate of consumption continues. However, a global shift towards market economies, increased information flows worldwide, and the modernisation of previously third-world countries such as India and China will lead to a higher per capita demand for energy than there is currently. Additionally, the world’s population is projected to reach nine million by 2050, which will also increase overall demand for energy. Therefore it is more likely that fossil fuel reserves will run out in approximately 40 years. Thus, it is integral that the development of new energy harvesting technologies starts now, so that they are ready for when fossil fuel reserves are depleted.
As most sources of environmentally friendly and renewable energy are only viable in certain areas and/or situations, a miscellany of new energy harvesting technologies would be the most feasible replacement for the combustion of fossil fuels. This hotchpotch of alternative energy sources could include geothermal or hot rock’ technology, photovoltaic technology, nuclear energy, and possibly more.
Geothermal technology would be an ideal means of generating electricity in areas where ample volcanic activity occurs, such as the ring of fire, a region that includes just about every country on the edge of the Pacific Ocean, except Australia, where approximately 90% of the world’s volcanic eruptions take place. Geothermal energy harvesting is not without its pitfalls, noisy drilling is necessary before a geothermal plant can be set up, and it produces small quantities of carbonate, chloride, and sulphide pollution. However, it is relatively clean and non-polluting, emitting no CO2, inexhaustible, safe, and relatively cost effective, especially in countries that have limited hydrocarbon resources, and can therefore be considered to be an ideal means of generating renewable energy.
In many areas where geothermal power is not a viable means of harvesting electricity, photovoltaic technology is. The sun’s heat is harvested using photovoltaic cells, a semiconductor, meaning that it allows electrons to flow in it when it is suitably ‘doped’ with traces of other substances. Photovoltaic cells are comprised of two slices of doped silicon, one positive and one negative, which are sandwiched together. Sunlight falls onto the cells’ top surfaces, freeing electrons from them, which are then collected by contact grids. Connected to a circuit, the electrons flow as an electric current, out from the negative terminal, into an appliance or battery, and back into the positive terminal. This is a renewable, safe and environmentally friendly way to garner energy. It also operates best in the sunniest parts of the world, which are often the poorest, and therefore helps alleviate poverty. There is much potential for solar power, largely due to the sliver cell research being conducted at the ANU, which substantially increases the cost competitiveness of photovoltaic compared to electricity generated from fossil fuels, by reducing the amount of expensive silicon in cells. However, energy generated photovoltaicly has to be stored in batteries, hydrogen, water or other matter, and solar power stations cannot be used as the only means of generating electricity in cloudy places, and must therefore be used in conjunction with other systems.
If an area is not suited to geothermal or photovoltaic electricity generation, nuclear energy, an environmentally friendly, means of generating electricity that has already been invested in massively by governments worldwide, could be used. Nuclear power is generated when the nucleus of a Uranium-235 atom is split by a neutron, which releases two or more of its neutrons, which go on to split other nuclei, causing a chain reaction. This fission heats a steam generator, where steam forms, an the steam turns a turbine and generator, which converts the kinetic energy to electron energy. Nuclear power is already used to generate approximately 17% of the world’s electricity. This could be much more once effective measures are put in place to prevent disastrous leaks’, such as that which happened at Chernobyl, from occurring, and a safe way to dispose of nuclear waste is found. As current uranium reserves are expected to last only one-hundred years, nuclear power would be ideal for use until other more long-term ways of generating energy are established.
In order to alleviate CO2 emissions while large-scale construction of nuclear reactors, photovoltaic plants, and geothermal power stations was underway, CO2 capture and storage technology could be employed at existing coal or oil-fired power stations. This would involve capturing and separating CO2 from other gases, and then compressing it, and transporting it to a suitable underground geological formation, into which it would eventually be assimilated. This would be relatively easy and cost-efficient, as numerous CO2 transmission pipeline already exist.
Thus, an unprecedented development of new energy harvesting technologies could be utilized to meet the energy requirements of the future, the energy requirements of the future being a means of generating electricity that is environmentally friendly, relatively cost-efficient, reliable, and renewable. This unprecedented development of new energy harvesting technologies that would replace simple exothermic chemical oxidation could come in the form of a miscellany of different forms of energy generation: geothermal, solar, nuclear, and possibly others.
