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Approved for public release; distribution is unlimited. / This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, it may not be copyrighted. / MBA Professional Report / The purpose of this paper is to explore the use of Enerrgy Saving Performance Contracts (ESPC) within the Department of Defense, focusing on the United States Air Force's utility and energy acquisition. The significant value of the ESPC is its alternative financing mechanism that authorizes Federal facilities regionalization without upfront investments. The paper focuses on Dyess Air Force Base's ESPC, as Dyess's benchmarking ESPC was selected for the Presidential Award recognition for Leadership in Federal Energy Management. The six major contracting processes within the three main management levels encompass many of the best-preactice characteristics. The interviews referenced herein with the service end-users, both the regional and local contracting officers, allow the reader to further understand how the Integrated Product Team's significant efforts resulted in a successful ESPC.

The dairy farming sector of European Agriculture is currently under considerable economic pressure so the aim of each farmer should be to produce saleable milk, at the lowest cost. One important area of concern is the expenditure on hot water for hygiene, as to be acceptable to the buyer the milk must have a low level of contaminants. Clean milk is produced from clean, healthy udders by means of equipment which is adequately and appropriately cleaned. To facilitate this hygienic milk production most dairies are eguipped with heaters to provide water at 40°C (for cleaning udders) and 80- 100°C (for plant cleaning). The practice of udder washing is a subjective process as it depends on the operator's judgement of a 'clean' udder and his view of necessity. In England and Wales there are two only accepted methods of plant cleaning, circulation cleaning and Acidified Boiling Water (A. B. W.). Prior to the. audit described it was expected that water and electricity consumption for plant cleaning would be predictable. To date there has been little information on the volume and temperature of water used on commercial dairy farms and the electricty consumed to produce this hot water. It is therefore difficult for farmers to make informed judgement on methods of reducing their electricity costs. Thirteen farms in South Devon have been monitored, to establish current practice: farmers were questioned about their water use; electricity and water consumption were metered for two years; and cleaning practices were observed. This survey has revealed that many non-standard cleaning methods are used on dairy farms, making the prediction of water and electricity consumption difficult. The management of equipment has been revealed as the most important aspect in determining the energy used. A computer model has been produced to simulate water heating in the farm dairy, which can be used to advise farmers as to the energy cost of their cleaning practices. This model has .been successfully used on several of the farms surveyed, on one farm its use resulted in energy savings in excess of 400 kWh per month.

With roughly about half of the energy used in buildings attributed to Heating, Ventilation, and Air conditioning (HVAC) systems, there is clearly great potential for energy saving through improved building operations. Accurate knowledge of localised and real-time occupancy numbers can have compelling control applications for HVAC systems. However, existing technologies applied for building occupancy measurements are limited, such that a precise and reliable occupant count is difficult to obtain. For example, passive infrared (PIR) sensors commonly used for occupancy sensing in lighting control applications cannot differentiate between occupants grouped together, video sensing is often limited by privacy concerns, atmospheric gas sensors (such as CO2 sensors) may be affected by the presence of electromagnetic (EMI) interference, and may not show clear links between occupancy and sensor values. Past studies have indicated the need for a heterogeneous multi-sensory fusion approach for occupancy detection to address the short-comings of existing occupancy detection systems. The aim of this research is to develop an advanced instrumentation strategy to monitor occupancy levels in non-domestic buildings, whilst facilitating the lowering of energy use and also maintaining an acceptable indoor climate. Accordingly, a novel multi-sensor based approach for occupancy detection in open-plan office spaces is proposed. The approach combined information from various low-cost and non-intrusive indoor environmental sensors, with the aim to merge advantages of various sensors, whilst minimising their weaknesses. The proposed approach offered the potential for explicit information indicating occupancy levels to be captured. The proposed occupancy monitoring strategy has two main components; hardware system implementation and data processing. The hardware system implementation included a custom made sound sensor and refinement of CO2 sensors for EMI mitigation. Two test beds were designed and implemented for supporting the research studies, including proof-of-concept, and experimental studies. Data processing was carried out in several stages with the ultimate goal being to detect occupancy levels. Firstly, interested features were extracted from all sensory data collected, and then a symmetrical uncertainty analysis was applied to determine the predictive strength of individual sensor features. Thirdly, a candidate features subset was determined using a genetic based search. Finally, a back-propagation neural network model was adopted to fuse candidate multi-sensory features for estimation of occupancy levels. Several test cases were implemented to demonstrate and evaluate the effectiveness and feasibility of the proposed occupancy detection approach. Results have shown the potential of the proposed heterogeneous multi-sensor fusion based approach as an advanced strategy for the development of reliable occupancy detection systems in open-plan office buildings, which can be capable of facilitating improved control of building services. In summary, the proposed approach has the potential to: (1) Detect occupancy levels with an accuracy reaching 84.59% during occupied instances (2) capable of maintaining average occupancy detection accuracy of 61.01%, in the event of sensor failure or drop-off (such as CO2 sensors drop-off), (3) capable of utilising just sound and motion sensors for occupancy levels monitoring in a naturally ventilated space, (4) capable of facilitating potential daily energy savings reaching 53%, if implemented for occupancy-driven ventilation control.

Most European stained glass windows have no protection to reduce the damage due to environmental exposure, and this is the case of the great gothic windows in the Uppsala Cathedral. Currently, the implementation of protective glazing systems is being carried out in order to reduce the damage of the stained glass. In this connection, an analysis of the energy saving potential of the protective system is of great interest. The main obstacle in the implementation of this kind of systems is a social rejection based on the fact that the additional panes perturb the appearance of the historic building. Thus, demonstrating that there would actually be an energy saving, with the corresponding economic saving, would help approving the implementation of the protective glazing system. Measurement data needed for the analysis were available since they were used in condensation studies for the damaging analysis. However, the fact that this data was not gathered thinking of the energy saving analysis and its difficulties, some limitations have appeared in the present study. Accordingly, the needed simplifications imply some uncertainty in the results. However, the reliability of the results and the conclusions that can be drawn from the analysis are contrasted with previous similar studies. Different methods of calculation and analysis will be discussed, and finally results for the heat transfer coefficients through the open air gap and through the whole double paned system will be obtained. Furthermore, an energy saving analysis will be carried out with the winter data for both the case of the case of the Sonens fönster and the case of also implementing a similar system in the rosette of the cathedral. As a result, the conclusions drawn will be that the implemented protective glazing system reduces the heat losses through the windows to less than a third and that savings of about 8700 kWh/year and 13000 kWh/year are achieved in the case of the system being implemented only in Sonenes fönster and also in the rosette respectively. Finally, a rough study of the condensation problem will be exposed and possible matters, along with some advices, of further studies regarding more accurate analysis of both the condensation and the energy saving analysis will be presented. / Church project

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Air compressor systems play a large role in modern industry. These compressors can account for a significant portion of a manufacturing facility’s electric consumption and any increase in efficiency can lead to economic benefits. Air compressors are sensitive to ambient conditions, as evidenced by the fact that compressing cooler and drier air decreases the amount of work required to compress the air. A thermodynamic model of an air compressor system was developed and several cases were run by using both vapor compression and absorption cycle chillers to cool and dehumidify the inlet air. The results show that the performance increases as much as 8 percent for the compressor system with absorption inlet cooling and as much as 5 percent when using vapor compression inlet cooling. Climates with higher humidity and temperatures can see the most benefits from inlet air cooling and dehumidification.

Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems are a major component of worldwide energy consumption, and frequently consist of complex networks of interconnected components. The ubiquitous nature of these systems suggests that improvements in their energy efficiency characteristics can have significant impact on global energy consumption. The complexity of the systems, however, means that decentralized control schemes will not always suffice to balance competing goals of energy efficiency and occupant comfort and safety. This dissertation proposes control solutions for three facets of this problem. The first is a cascaded control architecture for actuators, such as electronic expansion valves, that provides excellent disturbance rejection and setpoint tracking characteristics, as well as partial nonlinearity compensation without a compensation model. The second solution is a hierarchical control architecture for multiple-evaporator vapor compression systems that uses model predictive control (MPC) at both the supervisory and component levels. The controllers leverage the characteristics of MPC to balance energy efficiency with occupant comfort. Since the local controllers are decentralized, the architecture retains a degree of modularity—changing one component does not require changing all controllers. The final contribution is a new distributed optimization algorithm that is rooted in distributed MPC and is especially motivated by HVAC&R systems. This algorithm allows local level optimizers to iterate to a centralized solution. The optimizers have no knowledge of any plant other than the plant they are associated with, and only need to communicate with their immediate neighbors. The efficacy of the algorithm is displayed with two sets of examples. One example is simulation based, wherein a building is modeled in the EnergyPlus software suite. The other is an experimental example. In this example, the algorithm is applied to a multiple evaporator vapor compression system. In both cases the design method is discussed, and the ability of the algorithm to reduce energy consumption when properly applied is demonstrated.

This thesis has improved Baltazar's methodology for potential energy savings estimation from retro-commissioning/retrofits measures. Important improvements and discussions are made on optimization parameters, limits on optimization parameter values, minimum airflow setting for VAV systems, space load calculation, simulation of buildings with more than one type of system, AHU shutdown simulation, and air-side simulation models. A prototype computer tool called the Potential Energy Savings Estimation (PESE) Toolkit is developed to implement the improved methodology and used for testing. The implemented methodology is tested in two retro-commissioned on-campus buildings with hourly measured consumption data. In the Sanders Corps of Cadets Center, the optimized profiles of parameter settings in single parameter optimizations can be explained with engineering principles. It reveals that the improved methodology is implemented correctly in the tool. The case study on the Coke Building shows that the improved methodology can be used in buildings with more than one system type. The methodology is then used to estimate annual potential energy cost savings for 14 office buildings in Austin, TX with very limited information and utility bills. The methodology has predicted an average total potential savings of 36% for SDVAV systems with electric terminal reheat, 22% for SDVAV systems with hot water reheat, and 25% for DDVAV systems. The estimations are compared with savings predicted in the Continuous Commissioning assessment report. The results show it may be helpful to study the correlation by using generalized factors of assessment predicted energy cost savings to estimated potential energy cost savings. The factors identified in this application are 0.68, 0.66, and 0.61 for each type of system. It is noted that one should be cautious in quoting these factors in future projects. In the future, it would be valuable to study the correlation between measured savings and estimated potential savings in a large number of buildings with retrocommissioning measures implemented. Additionally, further testing and modifications on the PESE Toolkit are necessary to make it a reliable software tool.

MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015 / Demand side management (DSM) initiatives have been introduced by Eskom to reduce the deficit between the electricity generation capacity and the electricity usage within the country. DSM projects enable Eskom to reduce electricity demand instead of increasing generation capacity. DSM projects are more economical and can be implemented much faster than constructing a new power station. One particular industry where DSM projects can be implemented is on mines. Mines consume about 14.5% of South Africa’s electricity. Producing compressed air, in particular, is one of the largest electricity users on mines. It consumes 17% of the electricity used on mines. The opportunity, therefore, arises to implement DSM projects on the compressed air system of mines. Not only do these projects reduce Eskom’s high electricity demand, but they also induce financial and energy savings for the mine itself. However, during the implementation of a compressed air energy savings project, various challenges arise. These include, among others, operational changes, control limitations, industrial actions and installation delays. All of these can lead to a project not being delivered on time, within budget or with quality results. The purpose of this study is to investigate and address various problems that occur during the implementation of such a compressed air energy savings project. The study shows that although these problems have an impact on the results achievable with the project, significant savings are still possible. Project savings are achieved by reducing the amount of compressed air that is supplied, thereby delivering sufficient compressed air while minimising the amount of compressed air being wasted. During this study, a gold mine’s compressed air network was optimised. The optimisation resulted in an evening peak-clip saving of 2.61 MW. This saving was achieved daily between 18:00 and 20:00 when Eskom’s electricity demand was at its highest. It is equivalent to an annual cost saving of R1.46 million based on Eskom’s 2014/2015 tariffs. When savings from all periods throughout the day are taken into account, the project will produce an annual cost saving of R1.91 million.