Author: Ali Hasanbeigi, Ph.D.
Steam is used extensively as a means of delivering energy to industrial processes. On average, industrial boiler and steam systems account for around 30% of manufacturing industry energy use worldwide. In the textile industry, however, industrial boilers and steam systems account for majority of the fossil fuel used in this industry sector.
There exists a significant potential for energy efficiency improvement in steam systems; however, this potential is largely unrealized. The traditional approach in many countries is to focus on boilers only and not on the entire steam systems that include steam generation (boilers), distribution, recovery systems, and even steam end-use. While the use of more efficient boilers results in energy savings, optimization of the entire steam system will result in much larger energy savings. In developed countries, more attention is being paid to system optimization rather than individual equipment efficiency. In many developing countries, there is a need for this shift of paradigm to focus on system efficiency and systems optimization.
Figure: Steam System Schematic (Source: U.S. DOE/AMO, 2012)
A few years ago, I led a UNIDO-funded study to develop and apply a steam system energy efficiency cost curve modeling framework to quantify the energy saving potential and associated costs of implementation of an array of boiler and steam system optimization measures. The developed steam systems energy efficiency cost curve modeling framework was used to evaluate the energy efficiency potential of coal-fired boiler (around 83% of industrial boilers) and steam systems in China’s industrial sector. Nine energy-efficiency technologies and measures for steam systems are analyzed.
The study found that total cost-effective (i.e. the cost of saving a unit of energy is lower than purchasing a unit of energy) and technically feasible fuel savings potential in industrial coal-fired steam systems in China was equal to 23% and 28% of the total fuel used in industrial coal-fired boilers in China, respectively. The CO2 emission reduction potential associated with the cost-effective and total technical potential is equal to 165.82 MtCO2 and 201.23 MtCO2, respectively. By comparison, the calculated technical fuel saving potential for industrial coal-fired steam systems in China is approximately 9% of the total coal plus coke used in Chinese manufacturing in 2012 and is greater than the total annual primary energy use of over 160 countries in the world in 2010.
This report is published by UNIDO and can be downloaded from this link.
Cost-effective opportunities for energy efficiency improvement in the steam systems have been identified but frequently are not adopted, leading to what is called an “efficiency gap”. This is explained by the existence of various obstacles especially non-monetary barriers to energy-efficiency improvement such as lack of information and knowledge in companies especially in small and medium enterprises (SMEs), management concerns about other matters especially production rather than energy efficiency, lack of financial resources especially in SMEs which makes it difficult to adopt even cost-effective measures/technologies, lack of top management commitment and understanding, uncertainty about the new technologies and the fear of production disruption, lack of incentives by government and lack of enforcement for government regulations, etc.
Policies such as information dissemination and training programs for energy efficiency improvement and steam systems optimization, top management awareness-raising programs, financial incentives especially for SMEs, provision of steam systems assessment tools and guidelines, etc. are some of the programs that can address the aforementioned non-monetary barriers.
Many of the steam systems optimization measures involve improved operational and maintenance practices, which can be undertaken within a continuous improvement approach within industries. Hence, the adoption of energy management systems such as International Organization for Standardization (ISO) 50001- Energy Management Systems can aid in implementation of such measures in a more systematic manner. In addition, energy management systems can provide a framework that helps to ensure that the energy savings from steam systems optimization measures are sustainable and do not diminish over time. A principal goal of the ISO 50001 standard is to foster continual and sustained energy performance improvement through a disciplined approach to operations and maintenance practices. Therefore, it is crucial for policymakers to promote and incentivize the adoption of ISO 50001 or other energy management systems in industrial plants.
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