An Energy and Performance Exploration of Network-on-Chip Architectures

In this paper, we explore the designs of a circuit-switched router, a wormhole router, a quality-of-service (QoS) supporting virtual channel router and a speculative virtual channel router and accurately evaluate the energy-performance tradeoffs they offer. Power results from the designs placed and routed in a 90-nm CMOS process show that all the architectures dissipate significant idle state power. The additional energy required to route a packet through the router is then shown to be dominated by the data path. This leads to the key result that, if this trend continues, the use of more elaborate control can be justified and will not be immediately limited by the energy budget. A performance analysis also shows that dynamic resource allocation leads to the lowest network latencies, while static allocation may be used to meet QoS goals. Combining the power and performance figures then allows an energy-latency product to be calculated to judge the efficiency of each of the networks. The speculative virtual channel router was shown to have a very similar efficiency to the wormhole router, while providing a better performance, supporting its use for general purpose designs. Finally, area metrics are also presented to allow a comparison of implementation costs

Demand and Storage Management in a Prosumer Nanogrid Based on Energy Forecasting

Energy efficiency and consumers' role in the energy system are among the strategic research topics in power systems these days. Smart grids (SG) and, specifically, microgrids, are key tools for these purposes. This paper presents a three-stage strategy for energy management in a prosumer nanogrid. Firstly, energy monitoring is performed and time-space compression is applied as a tool for forecasting energy resources and power quality (PQ) indices; secondly, demand is managed, taking advantage of smart appliances (SA) to reduce the electricity bill; finally, energy storage systems (ESS) are also managed to better match the forecasted generation of each prosumer. Results show how these strategies can be coordinated to contribute to energy management in the prosumer nanogrid. A simulation test is included, which proves how effectively the prosumers' power converters track the power setpoints obtained from the proposed strategy.Spanish Agencia Estatal de Investigacion ; Fondo Europeo de Desarrollo Regional

Modelling electricity consumption in office buildings: an agent based approach

In this paper, we develop an agent-based model which integrates four important elements, i.e. organisational energy management policies/regulations, energy management technologies, electric appliances and equipment, and human behaviour, to simulate the electricity consumption in office buildings. Based on a case study, we use this model to test the effectiveness of different electricity management strategies, and solve practical office electricity consumption problems. This paper theoretically contributes to an integration of the four elements involved in the complex organisational issue of office electricity consumption, and practically contributes to an application of an agent-based approach for office building electricity consumption study

Advanced Integrated Power and Attitude Control System (IPACS) study

Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of simultaneously satisfying the demands of energy storage and attitude control through the use of rotating flywheels. It was demonstrated that, for a wide spectrum of applications, such a system possessed many advantages over contemporary energy storage and attitude control approaches. More recent technology advances in composite material rotors, magnetic suspension systems, and power control electronics have triggered new optimism regarding the applicability and merits of this concept. This study is undertaken to define an advanced IPACS and to evaluate its merits for a space station application. System and component designs are developed to establish the performance of this concept and system trade studies conducted to examine the viability of this approach relative to conventional candidate systems. It is clearly demonstrated that an advanced IPACS concept is not only feasible, but also offers substantial savings in mass and life-cycle cost for the space station mission

Understanding Residential Electricity Consumption Considering Energy Efficiency Policies and The Impact On the Electricity System

Electricity consumption increases substantially over the years where residential use significantly contributes to the overall consumption. The growth in the population and variety of home appliances together with increasing comfort levels of the people results in higher levels of residential electricity use. In fact, nearly one fourth of Turkey\u27s total electricity consumption is due to the domestic use. To achieve global sustainability targets and reduce the overall electricity use, focusing on the domestic consumption is crucial. In this research, the energy consumptions patterns of households are determined to identify the potential electricity savings existing in the residential sector. Moreover, specific policy recommendations, which can promote the behavioral change, are driven by measuring the responsiveness of people to different measures and the combinations of these measures such as information, feedback, rewards, and social influences. A survey was conducted to determine the patterns and the responsiveness of the residential customers. The results obtained from the survey are used to depict a general view of Turkish households towards electricity consumption behaviors and their energy efficiency attitudes. Responses indicate there should be more regulations and improvements in energy policy. An electricity allocation problem is solved in order to see possible impacts of behavioral change measures on the network. Scenarios are defined for each policy and allocation problem is solved to see the possible generation cost reduction. Also, gas emissions for each scenario is recorded to understand the possible effects of policies on the environment. Results show that behavioral change studies seem to be well worth to study. In order to reach residential efficiency, possible policy alternatives are suggested for Turkish households

Impact of Shutdown Techniques for Energy-Efficient Cloud Data Centers

International audienceElectricity consumption is a worrying concern in current large-scale systems like datacenters and supercomputers. These infrastructures are often dimensioned according to the workload peak. However, their consumption is not power-proportional: when the workload is low, the consumption is still high. Shutdown techniques have been developed to adapt the number of switched-on servers to the actual workload. However, datacenter operators are reluctant to adopt such approaches because of their potential impact on reactivity and hardware failures, and their energy gain which is often largely misjudged. In this article, we evaluate the potential gain of shutdown techniques by taking into account shutdown and boot up costs in time and energy. This evaluation is made on recent server architectures and future hypothetical energy-aware architectures. We also determine if the knowledge of future is required for saving energy with such techniques. We present simulation results exploiting real traces collected on different infrastructures under various machine configurations with several shutdown policies, with and without workload prediction

Energy efficiency in discrete-manufacturing systems: insights, trends, and control strategies

Since the depletion of fossil energy sources, rising energy prices, and governmental regulation restrictions, the current manufacturing industry is shifting towards more efficient and sustainable systems. This transformation has promoted the identification of energy saving opportunities and the development of new technologies and strategies oriented to improve the energy efficiency of such systems. This paper outlines and discusses most of the research reported during the last decade regarding energy efficiency in manufacturing systems, the current technologies and strategies to improve that efficiency, identifying and remarking those related to the design of management/control strategies. Based on this fact, this paper aims to provide a review of strategies for reducing energy consumption and optimizing the use of resources within a plant into the context of discrete manufacturing. The review performed concerning the current context of manufacturing systems, control systems implemented, and their transformation towards Industry 4.0 might be useful in both the academic and industrial dimension to identify trends and critical points and suggest further research lines.Peer ReviewedPreprin

Energy saving in tooling machines: a new unified approach to reduce energy consumption

Tooling machines are included in some EU directives, which set specific targets for the reduction of energy consumption in the near future. This paper aims to introduce a design approach that can be useful both for safety functional decomposition and for energy consumption evaluation of a generic tooling machines. This design approach tries to unify the existing divergent approach to energy efficient and safe tooling machines. A very simple application, already installed in some lathe machines currently produced in the EU, will give us all the necessary data (activity time counter) to perform a quantitative assessment in term of unified energy-efficient and safe machines. Moreover, the main results of an extensive survey made by a lathe manufacturer on real machines utilization and some measurement of wasted energy during standby mode of different machines will be presented. Those measurements show that it is not possible to define a proper LCA design method without considering that the wasted energy is a function of the size and type of processes and the specific operating conditions of the machine. Measurements, performed during stand-by of lathes with regenerative drives, are presented at the end of the paper