The technology used for the design report are natural gas and wind renewable energy for generation of electricity and heating supply for Sheffield. But compared to coal or oil, natural gas has more advantages than disadvantages as well as wind turbines also.
However, natural gas has some deficient disadvantages. Natural gas is mainly composed of methane. After releasing to the atmosphere, it is removed by gradual oxidation of carbon dioxide and giving the overall chemical reaction water by hydroxyl radicals formed in the troposphere or stratosphere. The reaction is
CH4+2O2à CO2+2H2O (Schmidt, 2004)
While the lifetime of atmospheric methane is relatively short when compared to carbon dioxide, with a half-life of about 7 years, it is more efficient at trapping heat in the atmosphere, so that a given quantity of methane has 84 times the global-warming potential of carbon dioxide over a 20-year period and 28 times over a 100-year period. Natural gas is thus a more potent GHG than carbon dioxide due to the greater global warming potential of methane. Direct emissions of methane represented 14.3% by volume of all global anthropogenic greenhouse gas emissions in 2004. (Howarth, et al., 2011). During extraction, storage, transportation, and distribution, natural gas is known to leak into the atmosphere, particularly during the extraction process. demonstrated that the leak rate of methane may be high enough to jeopardize its global warming advantage over coal. Natural gas is often described as the cleanest fossil fuel. It produces 25%–30% and 40%–45% less carbon dioxide per joule delivered than oil and coal respectively and potentially fewer pollutants than other hydrocarbon fuels (Herberg, 2011). Natural gas extraction also produces radioactive isotopes of polonium (Po-210), lead (Pb-210) and radon (Rn-220). Radon is a gas with initial activity from 5 to 200,000 becquerels per cubic meter of gas. It decays rapidly to Pb-210 which can build up as a thin film in gas extraction equipment (Chiras, 2012).
Coming to wind energy uses, more advantages than disadvantages when compared to oil, coal etc., not only wind but also other remaining renewable sources. But there are minor disadvantages to the environment as well. They are like in assessments of the life cycle global warming potential of energy sources, wind turbines have a median value of between 12 and 11 (gCO2eq/kwh) depending on whether off- or onshore turbines are being assessed. While a wind farm may cover a large area of land, many lands use such as agriculture are compatible with it, as only small areas of turbine foundations and infrastructure are made unavailable for use. There are reports of bird and bat mortality at wind turbines as there are around other artificial structures. Wind turbines generate some noise. At a residential distance of 300 meters (980 ft), this may be around 45 dB, which is slightly louder than a refrigerator.