This thesis aims to examine energy demand within UK industry and assess the improvement potential available through efficiency measures. The techniques employed throughout the work have been mainly engineering based, drawing on thermodynamics. Alongside this approach, an assessment of drivers and barriers to the technical potential was undertaken. Data availability was a key challenge in the current work. The variety in energy uses meant the use of publically available datasets was limited. A database was constructed utilising site level emissions data, and employed a subsector disaggregation that facilitated energy analysis. The database was used for an analysis of waste heat recovery options. Opportunities were identified in low temperature recovery, heat-ta-power technology, and the transport of heat. Each of these options would require further research and support to be fully realised. It was found that splitting the industrial sector into an energy-intensive and non-energy- intensive subsector, where the grouping was based on the drivers to energy efficiency, allowed generalisations to be made regarding future improvement potential. Based on analysis of past trends, it was found that the energy-intensive subsector has limited potential for further efficiency gains through currently used processes. To make significant improvements radical changes in current processes will be required. A study of the energy-intensive Cement subsector concurred with these findings. Future efficiency improvements in this subsector are likely limited without a shift to alternative cement production. The non-energy-intensive subsector was thought to have relatively greater improvement potential through existing processes. The analysis of these processes is limited by lack of data however. An analysis of the non-energy-intensive Food and drink subsector therefore focussed on improvements in supplying low temperature heat, rather than the efficiency of specific processes. Opportunities through improving steam systems, increasing combined heat-and-power use, and the adoption of heat pumps were found to offer similar improvement potentials.

The judicious use of energy by industries is a key lever for ensuring a sustainable industrial development. The cost effective application of energy management and energy efficiency measures offers industries with an effective means of gaining both economic and social dividend, also reducing the negative environmental effects of energy use. Unfortunately, industries in developing countries are lagging behind in the adoption of energy efficiency and management measures; as such missing the benefits of implementation. This study is aims at enhance the knowledge of industrial energy efficiency and management strategies in Ghana, by investigating the present level of energy (and efficiency) management practices in Ghana largest industrial park (i.e. Tema industrial area). The study also incorporates the investigation of also investigation of barriers to and driving forces for the implementation of energy efficiency measure; to shed light on the rationale for both the adoption and non-adoption of cost effective industrial energy efficient technologies in Ghana. This study was carried out using a semi-structure interview due to the explorative nature of the study. The interviews were conducted in sessions, in the first session respondents were asked describe the energy management strategies in used in the respective companies. In the second session, respondents were asked to fill a structured questionnaire covering the various aspects of the study. The results reveal that energy is poorly managed in the industrial area and there is an energy efficiency gap resulting from the low implementation energy efficiency measures. In addition the reveals that the important barriers impeding the implementation of cost effective energy efficiency technologies or measures in the surveyed firms principally stems from rational behavior economic barriers, which are deeply linked to the lack of government frameworks for industrial energy efficiency. The study also finds that economic gains related to ‘cost reductions resulting from lowered energy use’ and ‘threats of rising energy prices’ are the most important drivers for implementing energy efficiency measures or technologies.

The energy issue is presently in focus worldwide. This is not only due to increasing environmental concern regarding energy related emissions, but also due to the trend of increasing energy prices. Energy usage in the industrial sector in Sweden today represents about one third of the national energy use. A substantial part of that is related to support processes such as heating, ventilation and cooling systems. These systems are important as they are related both to energy cost and indoor climate management as well as to the health of the occupants. The purpose of this thesis is to reach a more comprehensive view on industrial energy efficiency and indoor environment issues related to industrial ventilation. This has been studied in three themes where the first part addresses barriers to energy efficiency in Swedish industries, the second theme discuss simulation as decision support, and the third studies the variable air volume system in industrial facilities. In the first theme three different studies were made: the first studies non-energy intensive companies in Oskarshamn in Sweden, the second studies the energy intensive foundry industry and the third study was part of an evaluation of a large energy efficiency program called Project Highland. These studies had several findings in common, such as the importance of a strategic view on the energy issue and the presence of a person with real ambition with power over investment decisions related to energy issues at the company. The studies also show that several information related barriers are important for decision makers at the studied companies. This shows that information related barriers are one reason in why energy efficient equipment is not implemented. In the second theme the use of simulation in the form of Computational Fluid Dynamics (CFD) and Building Energy Simulation (BES) are used as decision support for industrial ventilation related studies at two different industries, one foundry is investigated and one dairy. BES has mainly been used to simulate energy and power related parameters while CFD was used to give a detailed description of the indoor and product environment. Together these methods can be used to better evaluate the energy, indoor and product environment and thus enable the implementation of more efficient heating, ventilation and air-conditioning systems. In the third theme the use of Variable Air Volume (VAV) systems was evaluated, and was found to be an efficient way to reduce energy use at the studied sites. At the studied foundry the VAV system is predicted to reduce space heating and electricity use by fans by about 30%, and in the dairy case by about 60% for space heating and 20% for electricity.

Industrial energy efficiency is one of the most important means of reducing the threat of increased global warming. A higheruse of electricity than their European competitors, together with increased energy costs due to increasing energy prices in Swedish industry have negative impacts on results and competitiveness. Of great importance are thus different means which promote energy efficiency such as industrial energy policy instruments. However, cost-effective energy efficiency measuresare not always undertaken. In order to formulate and adopt accurate industrial energy end-use polices, it is thus of importanceto identify the barriers that inhibit the implementation of cost-effective energy efficiency measures. It is also of importance to identify the factors which promote the implementation. The aim of this thesis is to analyze industrial energy systems andmore specifically study factors that promote or inhibit energy end-use efficiency in Swedish industrial companies. Results from this thesis show that the implementation of technical energy efficiency measures is a major means for both energy-intensive and non-energy-intensive Swedish companies to overcome the threat of rising energy prices, for example for electricity. While energy efficiency measures in the non-energy-intensive industry are related mainly to support processes, measures in the studied energy-intensive Swedish foundry industry are related to both support and production processes. In the various case studies of barriers and driving forces, the most significant barriers to energy efficiency - with largevariations for some of the barriers among the studied cases - were found to be: technical risk such as risk of productiondisruptions; lack of time or other priorities; lack of access to capital; cost of production disruption/hassle/inconvenience; other priorities for capital investments; technology considered inappropriate at the site; difficulty/cost of obtaininginformation about the energy use of purchased equipment; and lack of budget funding. The largest driving forces, apart fromcost reductions resulting from lowered energy use, were found to be the existence of a long-term energy strategy and peoplewith real ambition. These driving forces did not, unlike the results of barriers to energy efficiency, vary widely across thestudied sectors. Investment decision support such as optimization has shown to add more information for larger capital-intensive investmentsin energy-intensive industrial SMEs. The thesis also showed that energy audits are an effective means, in terms of publicmoney spent per kWh saved, of providing the industry with information on potential energy efficiency measures. Based on the results presented in this thesis, a policy approach towards non-energy-intensive companies and industrial SMEsshould primarily include providing energy audits free of charge and involve the local authority energy consultants. / Industriell energieffektivisering är ett av de viktigaste sätten att reducera hotet om en globaluppvärmning. En högre relativ elanvändning, i jämförelse med europeiska konkurrenter, tillsammans med stigande energikostnader beroende av stigande energipriser för den svenskaindustrin, riskerar leda till försämrad lönsamhet och försämrad konkurrenskraft. Det är såledesav stor vikt att främja energieffektivisering, exempelvis genom olika typer av styrmedel. Lönsamma energieffektiviseringsåtgärder genomförs emellertid inte alltid, till följd av olikahinder för energieffektivisering. För att kunna formulera precisa styrmedel är det därför avstor vikt att dessa hinder som förhindrar implementering av energieffektiviserande åtgärder,identifieras. Det är också av stor vikt att identifiera drivkrafterna. Syftet med denna avhandling är att analysera industriella energisystem och mera specifikt studera faktorer somfrämjar och förhindrar effektiv slutanvändning av energi i svensk industri. Resultaten visar att hotet om stigande energikostnader, exempelvis beträffande elektricitet,både för icke energiintensiv och för energiintensiv svensk tillverkningsindustri, kan reduceraskraftigt om energieffektiv teknik implementeras. Medan åtgärder i icke energiintensiv industrifrämst är relaterade till stödprocesser så visar sig åtgärderna i den studerade svenska energiintensiva gjuteriindustrin vara relaterade till både stöd- och produktionsprocesser. I fallstudierna beträffande hinder och drivkrafter visade sig de största hindren vara - med storavariationer mellan fallen - tekniska risker såsom risk för produktionsstörningar och avbrott; brist på tid/andra prioriteringar; brist på kapital; kostnader för produktionsstörningar; ickeenergirelaterade investeringar prioriteras högre; tekniken passar ej för företaget;svårigheter/kostnader att erhålla korrekt information beträffande energianvändningen av deninköpta utrustningen; och brist på budgetmedel. De största drivkrafterna var, utöver kostnadsminskningar till följd av minskad energianvändning, förekomsten av en långsiktigenergistrategi och en eldsjäl. Drivkrafterna varierade inte, till skillnad mot hindren, så mycketmellan de olika undersökta fallen. Beslutsstöd såsom exempelvis optimering har visat sig kunna ge ökad information vid störremer kapitalintensiva investeringar i energiintensiva små- och medelstora företag. Vidare har energianalyser visat sig vara ett effektivt sätt, i termer av besparad kWh per statligt insattkrona, att ge industrin information beträffande möjliga energieffektiviserande åtgärder. Resultat från avhandlingen indikerar att ett stöd gentemot icke energiintensiva och små och medelstora företag framförallt bör inkludera statligt finansierade energianalyser med denlokala energirådgivaren som en deltagande aktör.

Improved industrial energy efficiency is viewed as an important means in the reduction of CO2 emissions and climate change mitigation. Various energy efficiency measures for improving energy efficiency exists, but even evaluated as cost-effective, there seems to be a difference between the energy efficiency measures that theoretically could be undertaken and which measures that actually are realised. On the other hand, industrial energy efficiency measures might yield extra effects, denoted as non-energy benefits, beyond the actual energy savings or energy cost savings. Based on interviews and a questionnaire, results showed that the Swedish industrial firms studied had observed various non-energy benefits. However, few of the non-energy benefits observed were translated into monetary values and included in investment calculations. Results indicated that this non-inclusion could be explained by lack on information on how to measure and monetise the benefits, but even if not translated into monetary values, some of the non-energy benefits were sometimes used qualitatively in investment decisions. The utilisation of the benefits seemed to depend on the type and the level of quantifiability among the perceived benefits. This thesis has also explored energy efficiency measures and non-energy benefits for a specific industrial energy-using process – compressed air. A literature review on energy efficiency in relation to compressed air systems revealed a large variation in which measures that could be undertaken to improve energy efficiency. However, few publications applied a comprehensive perspective including the entire compressed air system. Few non-energy benefits of specific energy efficiency measures for compressed air systems were identified, but the study provided insights into how non-energy benefits should be studied. This thesis suggests that energy efficiency and non-energy benefits in compressed air systems should be studied on specific measure level to enable the observation of their effects. However, the studies also addressed the importance of having a systems perspective; the whole system should be regarded to understand the effects of energy efficiency measures and related non-energy benefits.

La consommation énergétique dans l’industrie augmente de nos jours, avec l’amplification des activités industrielles dans le monde. En parallèle, la pénurie des énergies primaires et le réchauffement climatique obligent des exploitations sans cesse des énergies et des techniques alternatives, afin de développer durablement, et de satisfaire l’augmentation de la consommation. Ainsi, l’amélioration de l’utilisation énergétique dans l’industrie devient aussi un sujet important à développer et à étudier. Dans certains sites industriels, les rejets thermiques sont énormément dégagés dans l’environnement sans aucun traitement énergétique. Ses températures sont parfois, beaucoup plus élevées que l’ambiant. La valorisation de ces chaleurs est conseillée, par des systèmes de valorisation, pour la production de chaud, de froid et d’électricité. Ce traitement peut réduire significativement le gaspillage et améliorer l’efficacité énergétique dans l’industrie. C’est pour cette raison, plusieurs projets sont lancés. Le projet VALENTHIN (VALorisation ENergétique des rejets THermiques INdustriels) est pour but d’améliorer l’efficacité énergétique industrielle en valorisant les rejets thermiques ou en développant les processus industriels. Cette thèse concentre sur les études des systèmes de valorisation, particulièrement en ce qui concerne les différentes méthodes de simulation. Dans cette thèse, les bibliographies sont synthétisées, sur les différentes modélisations des systèmes de valorisation, surtout le système à absorption et le cycle de Rankine organique mentionnés dans ce projet. Par conséquent, une stratégie de modélisation est proposée et est montrée, pour les simulations des systèmes en régime permanent et en régime dynamique. Le choix des types de modélisation doit prendre en compte leurs avantages et leurs inconvénients, et aussi les besoins des utilisateurs, pour but de modéliser et développer des systèmes plus aisément et plus efficacement. / Energy consumption in industry is increasing today, with the amplification of industrial activities in the world. At the same time, the scarcity of primary energy and global warming are insist the use of alternative technologies and energies, in order to sustainably develop, and to satisfy the increase in consumption. Thus, improving energy use in industry is also becoming an important topic to be developed and studied. In some industrial sites, the waste heats are enormously released into the environment without any energy treatment. Its temperatures are sometimes, much higher than the ambient. The valorization of these heats is advised, by using the valorization systems, for the production of hot, cold and electricity. This treatment can significantly reduce the energy waste and improve energy efficiency in the industry. For this reason, several projects are being launched. The aim of the VALENTHIN project is to improve industrial energy efficiency by valorizing waste heat or by developing industrial processes. This thesis concentrates on the studies of valorization systems, particularly with regard to the different modeling methods. In this report, the bibliographies are synthesized, on the different models used for the valorization systems, especially the absorption system and the organic Rankine cycle mentioned in this project. Consequently, a modeling strategy is proposed and is shown for steady state simulations and dynamic regime systems. The choice of types of modeling must take into account their advantages and disadvantages and also the needs of the users, with the aim of modeling and developing systems more easily and efficiently.