Question

i) Compare in short paragraphs the global warming impact of solar energy and fossil fuels. (4 marks) ii) Today nearly all of Oman's electrical energy is generated from natural gas. But by year 2030, Oman targets to produce 30% of its electricity from renewable energy. If it is projected that by year 2030, Oman's total electrical energy need will be 30 x 109 kw-hr, estimate how many tons of global warming CO2 will be produced if Oman's electricity source will be from: a) 100% natural gas (1.5 marks) b) 30% solar and 70% natural gas (1.5 marks) Use averaged values of emission of CO2/kw-hr from your course material.

Answer 1

i). For solar energy, there are no emissions from generating electricity but there are other effects such as solar plants require large stretches of land, which may lead to a reduction in agricultural or forest land. Manufacturing solar PV uses hazardous materials which include sulfuric acid, nitric acid, hydrogen fluoride, and others. There are other emissions associated with the transportation of materials, maintenance, decommissioning, and dismantlement of the plant.

Fossil fuels generate a large number of emissions including carbon dioxide, NOx, SOx, and others in the environment. Carbon dioxide released from the coal, natural gas, and others in the atmosphere traps heat from the sun and increases the average temperature of the earth leading to the melting of glaciers and disturbances in weather patterns.

ii) Total energy need = 30*109 kW-hr (you may replace this with your course material data)

a) 100% Natural gas

assuming 0.4483 kg CO2 per kW hr

for 30*109 kW hr energy need, CO2 released = 30*109 *0.4483 kg =13.449 * 109 kg = 1.3449 * 107 tonnes of CO2

b) for 70% Natural gas, energy 70% CO2 will be released of the total = 0.7* 1.3449*107 = 9.4143*106  tonnes of CO2