Energy efficiency in electrical systems

Abstract

Mitigating climate change and achieving stabilization of greenhouse gas atmospheric concentrations — the objective of the United Nations Framework Convention on Climate Change (UNFCCC) — will require deep reductions in global Energy-related Carbon Dioxide (CO2) emissions. G-8 leaders called for a 50% reduction in greenhouse gas (GHG) emissions before 2050 to avoid the most serious consequences of climate change. Meeting this goal requires transforming the way energy is produced, delivered, and consumed across all sectors of the economy and regions of the world. Energy efficiency offers seemingly glittering promises to all-savings for consumers and utilities, profits for shareholders, improvements in industrial productivity, enhanced international competitiveness and reduced environmental impacts. As global energy demand continues to grow, actions to increase energy efficiency will be essential. The technical opportunities are myriad and potential savings real, but consumers and utilities have so far been slow to invest in the most cost-effective, energy-efficient technologies available. The energy efficiency of buildings, electric equipment, and appliances in use falls far short of what is technically attainable. Energy analysts have attributed this efficiency gap to a variety of market, institutional and technical constraints. Electric utility energy efficiency techniques have great potential to narrow this gap and achieve significant energy savings. This paper provides some of the recent trends in energy efficiency technologies that have been successful and also used widely worldwide. They are: 1) Energy efficient motors 2) Soft starters with energy saver 3) Variable speed drives 4) Energy efficient transformers 5) Electronic ballast 6) Occupancy sensors & Energy efficient lighting controls 7) Energy efficient Lamps This paper presents Case Studies of various energy efficient techniques used in a Steel Plant resulting in considerable Electrical energy savings varying from 10–15%. Electric motors drive both core industrial processes, like presses or roll mills, and auxiliary systems, like compressed air generation, ventilation or water pumping. They are utilized throughout all industrial branches, though the main applications vary. With only some exceptions, electric motors are the main source for the provision of mechanical energy in industry. In recent years, many studies identified large energy efficiency potentials in electric motors and motor systems with many saving options showing very short payback times and high cost-effectiveness. Furthermore, almost all electricity in India is generated by rotating electrical generators, and approximately half of that generated is used to drive electrical motors. Hence, efficiency improvements with electrical machines can have a very large impact on energy consumption. The key challenges to increased efficiency in systems driven by electrical machines lie in three areas: a. To extend the application areas of variable-speed electric drives through reduction of power electronic and control costs b. Secondly, to integrate the drive and the driven load to maximize system efficiency c. Finally, to increase the efficiency of the electrical machine. Lighting is a large and rapidly growing source of energy demand and greenhouse gas emissions. At the same time the savings potential of lighting energy is high, even with the current technology, and there are new energy efficient lighting technologies coming onto the market. Currently, more than 33 billion lamps operate worldwide, consuming more than 2650 TWh of energy annually, which is approximately 19% of the global electricity consumption. The introduction of more energy efficient lighting products and procedures can at the same time provide better living and working environments and also contribute in a cost-effective manner to the global reduction of energy consumption and greenhouse gas emissions.