This means not only a continuous flow of production, transport and assembly, but a constant consumption of energy as well. The reduction in energy consumption is therefore a major issue for the designers and operators of these installations, in particular because energy costs figure quite prominently among all the items on a company's bottom line. While energy is a major cost factor for consumers, it should not be forgotten that the generation of energy is also one of the main sources of the greenhouse gas CO2 with its harmful effects on global climate. In Europe, for example, the generation of one megawatt hour of energy causes an emission of approximately 447 kilograms of CO2 on average, depending on the regional energy mix of fossil fuels, nuclear power and renewable sources of energy. All over Europe, approx. 4.3 million GWh of energy is generated each year, leading to a total emission of nearly 2 billion tons of CO2. The share of energy consumed by industrial users can be up to 20 percent, depending on which region you look at.
Numerous national and international regulations and guidelines aim at reducing CO2 emissions worldwide. In addition, a range of simple measures can be taken to efficiently reduce energy consumption. One such element is the use of speciality lubricants. In every set of gears and every bearing which keep our industries going day after day, friction is generated – whereby valuable energy is lost. Measurements made on test rigs of Klüber Lubrication München KG have shown that the use of suitable special lubricants can help to minimise friction and increase the component's efficiency by up to 10 percent.
"In order to obtain a maximum of efficiency, tribologists look not only at the materials used for making the components but also at the ambient conditions under which the component is intended to work in real life", explains Mr. Siebert from Klüber Lubrication. "Very high or very low temperatures may play a major role, as may many other factors such as pressure, rotational speed or moisture. The selection of the right additives is decisive for the specific characteristics a lubricant will have."
An everyday example of this significant savings potential can be found in Munich's public transport system with its 761 escalators. These are driven via worm gears requiring an average driving power of 7.5 kW. With 4 000 operating hours per year, their total energy consumption is 30 000 kWh per unit. The use of a special gear oil can help to reduce energy consumption by some 10 percent. Consequently, the Munich public transport operator could cut costs by more than 200 000 Euro each year, and save the environment approximately 1 400 tons of CO2. In a mega-city like Shanghai, with its 2 600 escalators in the public transport sector alone, savings of huge proportions are feasible.
The potential for savings becomes even more apparent in another example: a large airport may utilise more than 20 000 gear units, for example in conveyor belts and escalators. Approximately 15 000 of them may be spur- and bevel gears with a mean power of 5 kW, and another 5 000 worm gears with a mean power of 15 kW. With some 4 000 operating hours a year and a utilisation rate of 40 percent, total power consumption is at approximately 240 GWh. Replacing a mineral oil by a polyglycol special oil will increase the efficiency of all gears by roughly 5.25 percent on average. The power saved thus totals 12.6 GWh – this is the annual power consumption of approx. 3 000 private households. 12.6 GWh, that's 12 600 MWh – leading, on European average, to the emission of more than 5 600 tons of CO2. Based on an energy price of 9.5 cent per kWh in Germany, more than a million Euros can be saved this way.
"These calculations clearly show how a lower energy consumption can benefit the environment and at the same time reduce operating costs in the long term," explains Mr. Siebert. "When looking at the whole picture in context, and when considering the cost-benefit aspect, a seemingly more expensive high-performance lubricant can in fact turn out more economical. After all, less friction means less wear, longer maintenance intervals, lower energy consumption and hence less strain on valuable resources."
Klüber Lubrication has a leading position worldwide in the development and manufacture of speciality lubricants. The company has developed tribological solutions in nearly all branches of industry and market sectors for more than 80 years. Klüber Lubrication has approximately 1 800 staff in more than 30 countries and offers several thousand speciality lubricants in constant high quality worldwide.