SARI_DISCUSSION

Alternative Energy Sources

Recently energy crisis is always being a highlight issue. Now should we change our energy sources to the better one? Alternative energy sources are becoming increasingly attractive as the energy crisis becomes more severe. They are solar heating system, ocean waves and tides energy, coal, and garbage.
First, solar heating systems, which use the sun’s radiation as a source of energy, are a promising alternative energy source. Solar energy is one the most resourceful sources of energy for the future. One of the reasons for this is that the total energy we receive each year from the sun is around 35,000 times the total energy used by man. However, about 1/3 of this energy is either absorbed by the outer atmosphere or reflected back into space.
Second, government and private industry, are even investigating the possibility of capturing the power of ocean waves and tides for conversion into usable energy. Even the power of the tides can be harnessed to produce electricity. Similar to the more conventional hydroelectric dams, the tidal process utilizes the natural motion of the tides to fill reservoirs, which are then slowly discharged through electricity-producing turbines.
Third, coal, is a burnable black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons. Coal is a nonrenewable energy source because it takes millions of years to create. The energy in coal comes from the energy stored by plants that lived hundreds of millions years ago, when the earth was partly covered with swampy forests. For millions of years, a layer of dead plants at the bottom of the swamps was covered by layers of water and dirt, trapping the energy of the dead plants. The heat and pressure from the top layers helped the plant remains turn into what we today call coal. Once again coal becomes an acceptable fuel as the nation searches for solutions to the energy shortage.
Even the garbage is seen as a potential source of energy. Garbage or city solid waste can be a source of energy by burning it in special power plants or by capturing the gases it releases. When trash is burned at special waste power plants, it produces steam that can be used either to heat buildings or to generate electricity. We can also obtain energy from garbage by letting it rot in landfills. It releases methane gas – also called biogas – that can be collected and used as a fuel source.
So we do not need to be worried anymore about the crisis of energy because we have found so many alternative energy sources as the replacement energy. Even the alternative energy sources are less pollution for the environment than the others.