---

---

---

---

Science Current Events and Science News RSS Feeds

---

---

Email a Friend Printer Friendly

Keeping the environment clean with compressed air

March 02, 2001

Savings of up to 50 per cent possible / 320 000 compressors currently in use EU-wide / Complex management structures

Annually, the production of compressed air accounts for about 10 per cent of total industrial electricity consumption in the European Union. This corresponds to over 80 billion kilowatt hours per year. In spite of this high figure, the energy efficiency of many compressed air systems is extremely low. The Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe, can now show that savings of 50 per cent are possible.

According to the survey conducted by Fraunhofer researchers together with other international partners, there are currently around 320 000 compressors between 10 and 300 kilowatts being operated in the European Union. The market for compressed air systems is stable in Europe, with 1 to 2 per cent growth in Italy, Greece and Spain and no growth in the other EU countries. Compressors are very long-lived capital goods. Systems between 90 and 300 kilowatts have an average lifespan of 16 years. They operate for about 56 000 hours within this period.

The efficiency of a compressed air system depends on the individual components as well as the overall system design and operation. Energy savings are most easily realised when installing a new system. However, it frequently helps to replace components of an existing system. Large savings can be made through suitable maintenance and regular inspections to detect and eliminate air leaks.

On average, the economic and technical energy savings achievable over a period of 15 years amount to more than 30 per cent. All the technical measures examined by Fraunhofer researchers have payback times of less than three years. The most important measures are reducing losses from air leaks, an improved system design, the use of adjustable speed drives and waste heat recovery.

Although the technical measures necessary to increase energy efficiency in compressed air systems are more profitable than many other investments, they are often not implemented for organisational reasons. There are essentially three reasons involved: there is no clear cost centre for compressed air production and use, there is a lack of awareness of the problem and the management structures are too complex.

Since the majority of obstacles to implementing energy-efficient measures stem from organisational factors, the possible solutions are oriented towards changes in organisation. The researchers therefore propose various measures ranging from advertising campaigns through demonstration and pilot projects right up to taxes on energy or on CO2 emissions.

As a recommendation for action, the authors summarised the measures in two complementary programmes. An "Awareness Raising Programme" and an "Economic and Regulatory Programme" which has a stronger emphasis on profitability considerations, regulations, subsidies and taxes. In contrast, the Awareness Raising Programme includes information and decision aid measures. Researchers expect combined savings of up to 24.7 per cent or about 20 billion kilowatt hours per year from these two programmes. This is equivalent to a saving of more than 10 million tonnes CO2 by the year 2015.

The book will be published at the end of February in Log_x- Verlag, Stuttgart, and can be ordered in bookshops or directly from Fraunhofer ISI (ISBN 3-932298-16-0). The published version has 175 pages and costs DM 78,- (about 40EUR). At the same time, an online version will be available in the internet under www.isi.fhg.de/e/.

Fraunhofer-Institute for Systems and Innovation Research (ISI)