The Development and Issues of Energy-ICT: A Review of Literature with Economic and Managerial Viewpoints

This paper reviews the economic and managerial literature on the relationship between energy-ICT and the development of the green energy economy. It is summarized that there are four lines of existing literature on energy-ICT: cost and benefit analysis, fair competition issues, cybersecurity issues, and promotion policy issues. Even though ICT is energy-consuming, most of the existing empirical studies support the idea that energy-ICT has net positive effects on energy savings, energy efficiency improvement, emission reduction, and economic growth at both enterprise and economy-wide levels. Energy-ICT equips the platform operator with higher bargaining power, such that a governance mechanism to assure the fair access right of each entitled participant is required. A smarter energy-ICT network also becomes riskier, and hence the cybersecurity protection is more important than before. Future research and development opportunities remain on these issues of the fair competition, cybersecurity, and promotion policy of energy-ICT.

BISWSRBS: A Winograd-based CNN Accelerator with a Fine-grained Regular Sparsity Pattern and Mixed Precision Quantization

Field-programmable Gate Array (FPGA) is a high-performance computing platform for Convolution Neural Networks (CNNs) inference. Winograd algorithm, weight pruning, and quantization are widely adopted to reduce the storage and arithmetic overhead of CNNs on FPGAs. Recent studies strive to prune the weights in the Winograd domain, however, resulting in irregular sparse patterns and leading to low parallelism and reduced utilization of resources. Besides, there are few works to discuss a suitable quantization scheme for Winograd. In this article, we propose a regular sparse pruning pattern in the Winograd-based CNN, namely, Sub-row-balanced Sparsity (SRBS) pattern, to overcome the challenge of the irregular sparse pattern. Then, we develop a two-step hardware co-optimization approach to improve the model accuracy using the SRBS pattern. Based on the pruned model, we implement a mixed precision quantization to further reduce the computational complexity of bit operations. Finally, we design an FPGA accelerator that takes both the advantage of the SRBS pattern to eliminate low-parallelism computation and the irregular memory accesses, as well as the mixed precision quantization to get a layer-wise bit width. Experimental results on VGG16/VGG-nagadomi with CIFAR-10 and ResNet-18/34/50 with ImageNet show up to 11.8×/8.67× and 8.17×/8.31×/10.6× speedup, 12.74×/9.19× and 8.75×/8.81×/11.1× energy efficiency improvement, respectively, compared with the state-of-the-art dense Winograd accelerator [20] with negligible loss of model accuracy. We also show that our design has 4.11× speedup compared with the state-of-the-art sparse Winograd accelerator [19] on VGG16.

Identification of Energy Efficiency Improvement Measures of an Existing Residential Building Using Audit-Assisted Energy Simulation and Analysis

Depleting energy sources are forcing humans to preserve energy and utilize it wisely. Globally, researchers are working to find ways to manage the energy crisis. Residential buildings are considered to be in the most energy demanding sector. Therefore, efforts are being made to reduce the increasing energy consumption and make the buildings energy efficient. The paper focuses on finding ways to retrofit the existing residential buildings into energy efficient buildings. This study evaluated the energy performance of a G+2 residential building with a total of 3 floors covering an area of 991.68 sq. meters, to identify relevant potential improvement measures. An energy analysis of the building was performed using information modeling assisted with energy audit data for accurate and realistic analysis. It was found that there is potential for the reduction of the annual energy usage and annual energy cost up to 2.33% and 4.54% respectively, by making improvements in the window to wall ratio. Another potential energy cost saving of 14.8% can be achieved by changing Heating, Ventilation, Air Conditioning (HVAC) type, and 7.62% of a reduction in cost can be achieved through modification in lighting fixtures. Moreover, installing solar photovoltaic panels can save up to PKR 1 million, and natural ventilation could result in saving more than PKR 0.2 million annually.

Importance of Machine Modernization in Energy Efficiency Management of Manufacturing Companies

Saving energy and looking for alternative energy sources are both elements of energy efficiency management, which is still a significant challenge for many companies around the world. Unfortunately, energy efficiency in companies is often equated only with thermo-modernization or the replacement of lighting. However, one of the most important methods of improving energy use in manufacturing companies may be the modernization of the machine park. Therefore, the main purpose of the paper was to investigate the activities of enterprises in the field of the modernization of machines and the impact of this on the actual improvement of energy efficiency. The modernization of machines in production plants is understood as adapting new parts to the old device or rebuilding the machine in such a way that it can cooperate with its new subassemblies. Companies usually decide to modernize the machinery fleet, bearing in mind the benefits of production efficiency, and they do not always combine this modernization with energy efficiency improvement measures. This is confirmed by the presented results of a survey conducted with a group of 111 manufacturing companies. Several important statistical relationships in the studied area were indicated by conducting an analysis based on the chi-square test and, in some cases, by clarifying the results of the z-test with the Bonferroni correction.

Energy Performance Benchmarking of Process Refrigeration Units

Process refrigeration units are one of the major energy consumers at gas processing plants. Owing to the higher energy consumption, evaluation and benchmarking of energy performance of the refrigeration units is very important for identification of energy saving opportunities. In this regard, an energy performance benchmarking study was performed by detailed assessment and evaluation of the existing process refrigeration units to identify potential of energy efficiency improvement. The study encompassed twenty-one (21) process refrigeration units installed at five (05) different sites. The methodology included collection and analysis of design & operation data and review of key variables like percent load, anti-surge valve opening, condensing temperature & pressure and chilling temperature etc. Energy Performance Indicators (EnPIs) considered for the benchmarking were compressor's specific energy, coefficient of performance (COP) and relative COP (RCOP). A thermodynamic model was developed for each unit to ascertain the refrigeration load. Instead of usual high level benchmarking techniques, the study considered unit and equipment level benchmarking which provided better insight of the systems and helped in finding opportunities for energy efficiency improvement. Further, COP which is generally considered as a benchmarking EnPI, only considers refrigeration load and energy consumption, whereas, this study introduced a new EnPI named "Relative COP" which additionally takes into account the chilling and condensing temperatures and gives true energy performance benchmarking.

Ecological Adaptive Cruise Control of Plug-in Hybrid Electric Vehicle with Connected Infrastructure and On-Road Experiments

This paper examines both mathematical formulation and practical implementation of an ecological adaptive cruise controller (ECO-ACC) with connected infrastructure. Human errors are typical sources of accidents in urban driving, which can be remedied by rigorous control theories. Designing an ECO-ACC is, therefore, a classical research problem to improve safety and energy efficiency. We add two main contributions to the literature. First, we propose a mathematical framework of an online ECO-ACC for Plug-in Hybrid Electric Vehicle (PHEV). Second, we demonstrate ECO-ACC in a real-world which includes other human drivers and uncertain traffic signals on a 2.6 [km] length of the corridor with 8 signalized intersections in Southern California, USA. The demonstration results show, on average, 30.98% of energy efficiency improvement and 8.51% additional travel time.