The concept of energy efficiency or use of energy efficiently by making savings in its use is vitally important for our lives as well as industrial plants that use a very large part of the energy consumption. The cheapest energy is the saved energy. Saving means a use of less energy for doing a work. Energy saving does not imply the non-use of energy. Energy saving means a use of energy more efficiently by general known methods, development procedures and the latest technologies and observing the standards of social life. The energy surveys done for different sectors of industry have shown that it is possible to achieve between 5 and 40 % energy savings at 95 % of industrial plants. It is more interesting to know that minimum 10 % energy savings potential is present at industrial plants with very low investment or no investment at all. The ratios stated above shows expressly how crucial it is to focus on the energy consumption and savings therein.
To minimize carbon emissions that arise as a result of the burning of fossil fuels and thereby prevent the global warming caused by such emissions and also the climatic changes that arise in association with the former, there are two ways: (1) Utilize renewable environment-friendly energy resources instead of fossil fuels, and (2) Utilize energy more efficiently and save energy. With the energy saving in industrial plants, the aim is to reduce the amount of energy consumed per product. Energy saving includes measures taken to identify fields where energy is used unnecessarily and minimize or entirely eliminate the waste of energy. Thus, the producer might produce the same amount of goods or services with a reduced amount of energy, improving his competitiveness in national and international markets.
Energy Use in Industry
Industry is the major user of energy in modern society, accounting for rougly 40% of final energy use. Coal or oil are heavily used, especially by primary industry and manufacturing and refining. Gas is being used increasingly to replace coal because it is a cleaner fuel producing less impact on the environment. Electricity is only a minor component of industrial energy use although its use in driving electric motors is very important. The major sectors within industry can be categorized as follows:
Manufacturing: This includes the processing of primary resources into consumer products such as food, textile, furniture and wood products, paper, petrochemical, cement, glass, iron and steel, non-ıron metals and machinery manufacturing. Such activities often occur in the industrial zones of major cities.
Power Generation: The power generation industry is a massive user of fossil fuels and accounts for more than 50% of international greenhouse gas emissions. Many power stations are very inefficient and there are strong economic and environmental incentives to save energy in the power supply industry. Most cities have major power stations and these are often a cause of air pollution as well.
Mining: This is a primary industry which generally occurs outside cities, often in remote parts of the country. Energy intensity is high in most mining operations but there is an incentive to save energy because energy wastage is reflected in the cost of the minerals.
Agriculture: Another major user of primary energy which takes place in rural areas and is largely beyond the scope of city governments to influence it.
Construction: The construction is a modest user of energy, particularly liquid fuels because this activity often takes place at sites where electric power is not readily available. Considerable savings are available in this sector because there is often a large amount of wastage in construction activities. The main focus will therefore be on energy savings in manufacturing and power generation as these are the major users of industrial energy in cities.
Energy Saving Methods in Industry
The methods for achieving energy savings in industry are quite different to those for most other sectors. Industry is very diverse and is often controlled by very large multi-national corporations. In this context the appropriate approach needs to be carefully considered. Industry is generally receptive to efforts to cut its energy costs but it is less likely to be attracted to regulatory measures that increase its operating costs. The technical options available for energy savings in the industrial sector are as diverse as the industries themselves. However, they principally revolve around the saving of energy in areas such as:
- Gas Turbines
- Gas Compressors
- Steam Turbines
- Condensers / Heat Exchangers
- Cooling Towers
- Combined Heat and Power (Cogeneration)
- Heat Recovery Systems
- Hot Water and Steam Distribution Lines
- Cold and Hot Heat Insulation
- Pumps and Water Pipes
- Compressors / Pressurized Air Systems
- Generators / Transformers
- Electric Motors
- Lighting Systems