ELECTRICITY AND WATER PRODUCTION IN THE EMIRATE OF ABU-DHABI AND ITS IMPACT ON THE ENVIRONMENT

The history of electricity production in the Emirate of Abu Dhabi is reviewed in short, with emphasis on large projects completed during the past decade. Electricity is generated by gas- and steam turbines at a rated capacity of 2000 MW in five major power stations, and is transmitted and distributed by standard 11, 33, 132, 220 and 400 kV lines. The variation of monthly power consumption with time follows bell-shape curves with maxima at the month of August. The curves run parallel to those of atmospheric temperature and humidity and reveal that the largest wattage goes into the operation of air conditioning units. Curves representing the hourly variation of electricity consumption at the peak (August) and at the minimum (February) during working and non-working days are constructed and their results discussed. The development of seawater desalination in the Emirate during the past decade is similarly presented. Water is cogenerated with electricity in the three coastal stations. Curves showing the monthly water production have flat tops covering the time between May and November. The implications of these curves are discussed. The production of electricity and water is a relatively clean industry. However, unlike other chemical processes, the interaction between cogeneration and the environment is mutual, A clean sea environment is a prerequisite for pure water production. The major sources of pollution in the seawater are oil, human- and industrial effluents. The role of each of these factors is outlined in short. In combating oil pollution, oil dispersants are not to be applied at- or near seawater intakes. The operation of P&D Plants causes air and water pollution. Air pollution results form the combustion of natural gas and diesel oil for running gas turbines and steam boilers. Large quantities of heat-releasing carbon dioxide and of health hazardous sulphur and nitrogen oxides are produced. By using high discharging chimneys the effusing gases are diluted to practically undetectable harmless limits. Pollution of the sea during desalination results from pre-chlorination at the seawater intakes, as well as from the discharge of the hot concentrated brine at the outfall. The discharged brine also brings in measurable quantities of copper, nickel and chromium, resulting from the attack on the distillers materials, Acidification of the outfall by the spent acid resulting from distillers acid-wash momentarily changes the seawater chemistry of the outfall. Similarly, polyphosphate added as antiscalant acts as a nutrient to algae, causing their flourishing. All these effects influence the marine biota picture at the intakes and outfalls as compared to that of the open sea.