Energy-saving Perspective Research Articles

Seismic Retrofit Measures for Masonry Walls of Historical Buildings, from an Energy Saving Perspective

The planning of energy saving and structural retrofit interventions on masonry buildings are usually two separate projects; combined interventions are rare. Solutions tackling both aspects can reduce total refurbishment costs and improve global building performance. However, heavy interventions on the envelope have to be carefully designed in order to improve both seismic and energy performance whilst mitigating environmental impact. National energy saving regulations are generally less strict for historical buildings, making this category of buildings very interesting not only because of their widespread diffusion across Italy but also because of the possibility of planning interventions that will allow significant improvements by combining building efficiency and safety. This research looks at these aspects and proposes new methods for refurbishing masonry buildings combining seismic improvements and energy saving interventions. Among those mostly commonly applied on masonry buildings in Italy, and described in this paper, are various combined retrofit interventions, and we report the results of these interventions on thermal transmittance reduction and global costs.

A Review of Green Building Development in China from the Perspective of Energy Saving

This paper reviews the history of green building development and assessment standards in China, particularly from the perspective of energy saving. It is divided into four parts: (1) the development of policies of green building in China that have been proposed for meeting energy-conservation and emission-reduction targets; (2) the scientific research on green building by the Chinese government, including the promotion of maximum resource sustainability, environmental protection, and the reduction of pollution; (3) the development of assessment standards for green building in China; and (4) the development of green building technologies in China.

Effect of different renovation actions, their investment cost and future potential

65% of the buildings in Västerås, situated in the region of Mälardalen, Sweden were built before 1970. It is thus time for renovation. The situation is the same in most cities in Sweden and Northern Europe. The depth of renovation can be quite different. In this paper we evaluate some examples where cost is compared to energy saving effect. How to plan renovation to make use of the available capital in the cities is discussed. As a complement to direct renovation actions also behavior change with respect to energy is discussed and exemplified. The cost for energy actions in relation to other renovation aspects is discussed especially for the passive house case in Allingsås, Sweden. The passive house center calculate an extra cost for passive house standard to be 10 000 €/apartment while an external consultant has the figure 40 000 € of the total cost of 120 000 €. With this space heating can be 18 kWh/m2.year, or a reduction by 84 % with respect to space heating and 62% for overall heat and hot water demand. If you use the latter cost figure passive house standard is not motivated from an energy savings perspective while if using the lower figure it is very interesting. For the other less deep renovations we see that adding more insulation and three glass windows is motivated if the degradation has been strong, while a simpler renovation may be ok if the outer surface coating is not too bad. For these less deep renovations we see cost figures of 65 €/m2 respectively 28 €/m2 with reduction of heating and hot water demand of 56 % respectively 34 %.

Is Passive or Active House Needed In Face of Global Warming?

The article aims to determine how effective the stricter current requirements for the building envelope insolation are from the economic energy savings perspective. The article deals with a mathematical method for economic assessment of optimal building thermal insulation. The mathematical methods used in this article are based on evaluating the break-even point between the construction expenditures and the economic profit. Recent research shows that energy savings achieved solely through stricter standards applied to the building envelopes are limited in their ability to achieve maximum results. As the ratio of building volume to building envelope increases, further energy saving measures applied to the building envelope produce lower energy saving effects. Energy savings achieved using renewable energy resources, recuperation systems are much more effective. Research shows that much greater effect can be achieved by combining optimal building envelope energy efficiency measures with new requirements related to renewable energy sources and recuperating systems, such as solar batteries, wind turbines or heat pumps.

Thermal modeling and experimental research of a gas engine-driven heat pump in variable condition

In order to analyze the influence of various factors on the system performance of the gas engine-driven heat pump system with waste heat recovery, theoretical model of a gas engine-driven heat pump is conducted in this paper. The thermal modeling of the gas engine-driven heat pump including both the heat pump and the gas engine system was performed and the system performances under different operating parameters were simulated. The results show that the engine speed and the outdoor air temperature affected the system performance significantly. With the engine speed increasing from 1400rpm to 2000rpm, the heating capacity increased by 26.9% while system primary energy ratio (PER) decreased by 17.6% for the air temperature of 10°C. When the outdoor air temperature reduced from 10 to 2°C, the heat capacity reduced by 14.6% but the system PER decreased by 11.8% with the engine speed of 1800rpm. The water inlet temperature act insignificantly on heating capacity, while it had some influence on the system PER. With the water inlet temperature increasing from 38 to 44°C, the system PER decreased by 5.7% and 4.4% for the outdoor air temperature of 10 and 2°C, respectively. The experimental test is also carried out to validate the simulation models. The comparison of modeling results and the experimental measured values for various amounts of the heating capacity, PER, waste heat recovery and the percentage of heat recovery showed 4.8%, 4.6%, 6.7% and 5.6% average difference percentage, which indicated an accepted agreement. From the perspective of energy savings, the gas engine-driven heat pump should be operated with engine speed as low as possible in the case of meeting the heating requirements.

Industrial Investments in Energy Efficiency: A Good Idea?

Yes, from an energy-saving perspective. No, once we factor in the negative output and productivity adoption effects. These are the main conclusions we reach by conducting the first large-scale study on cogeneration technology adoption – a prominent form of energy-saving investments – in the U.S. manufacturing sector, using a sample that runs from 1982 to 2010 and drawing on multiple data sources from the U.S. Census Bureau and the U.S. Energy Information Administration. We first show through a series of event studies that no differential trends exist in energy consumption nor production activities between adopters and never-adopters prior to the adoption event. We then compute a distribution of realized returns to energy savings, using accounting methods and regression methods, based on our difference-in-difference estimator. We find that (1) significant heterogeneity exists in returns; (2) unlike previous studies in the residential sector, the realized and projected returns to energy savings are roughly consistent in the industrial sector, for both private and social returns; (3) however, cogeneration adoption decreases manufacturing output and productivity persistently for at least the next 7-10 years, relative to the control group. Our IV strategies also show sizable decline in TFP post adoption.

Energy‐efficient link selection scheme in a two‐hop relay scenario with considering a mobile relay

Recently researches show that significant energy saving can be achieved by introducing mobile relays into wireless sensor networks. However, due to the extra transceiver circuit energy and the mobility energy consumed by the mobile relay, it is not always better to pass data through the relay rather than to send it from source to destination directly. In this study, the authors study a novel link selection problem in a two-hop relay scenario where the relay has the ability to move. In this scenario, data from source can be passed through three kinds of links: the direct link, the initial relay link and the adjusted relay link. From the energy-saving perspective, the optimal moving direction, the position adjustment criterion and the optimal position of the mobile relay are firstly studied through mathematical analysis. Based on a comprehensive discussion of the energy performances of these three kinds of links, and energy-efficient link selection scheme is then presented. Both the amount of data to be sent and the distance between source and destination are shown to be closely related to the link selection scheme. Finally numerical simulations are carried out to verify the theoretical results.

A simple tool for estimating city-wide annual electrical energy savings from cooler surfaces

We present a simple method to estimate the maximum possible energy saving that might be achieved by increasing the albedo of surfaces in a large city. We restrict this to the “indirect effect”, the cooling of outside air that lessens the demand for air conditioning (AC). Given the power demand of the electric utilities and data about the city, we can use a single linear equation to estimate the maximum saving. For example, the result for an albedo change of 0.2 of pavements in a typical warm city in California, such as Sacramento, is that the saving is less than about 2 kW·h of electrical energy per modified m2 per year. This may help decision makers choose which heat island mitigation techniques are economical from an energy-saving perspective.

공동주택 세대 위치에 따른 에너지 부하량

In Korea, multi-housing in one of the most common types of residential space due to its easy management and convenience. In particular, south-facing plate-type(一) multi-housing has attracted a great deal of public interest because it consumes less energy compared with other types of multi-housing, making it advantageous from an energy-saving perspective. Although there have been many studies on the annual energy consumption of multi-housing in relation to building shape and area of window, there have not been sufficient research on the annual energy consumption of multi-housing in relation to individual units of the multi-housing. The purpose of this study is to propose a strategy for reducing energy consumption in plate-type(一) multi-housing, taking the units with the lowest energy consumption as the standard. The result, Standard Models's energy load was as 4000 ~ 5600kWh, and Passive Houses's energy load was less than Stand Models at the 1600kWh.

Energy aware RAID configuration for data intensive applications in enterprise storages

Energy consumption of storage at data centres is increasing rapidly. Large storage facilities have various RAID configurations incorporating different RAID levels, numbers of drives, and media types. Nevertheless, few discussions of RAID configurations have been pursued from an energy-savings perspective. We first investigate how different RAID configurations affect not only application performance but also power consumption of storage installations. We then present the simulation results for power consumption and application performance obtained using various RAID configurations. These results reveal that a RAID configuration strongly impacts energy conservation based on application I/O features.

Utilize Signal Traces from Others? A Crowdsourcing Perspective of Energy Saving in Cellular Data Communication

With the tremendous growth in wireless network deployment and increasing use of mobile devices, e.g., smartphones and tablets, improving energy efficiency in such devices, especially with communication driven workloads, is critical to providing a satisfactory user experience. Studies show that signal strength plays an important role on energy consumption of cellular data communications. While energy consumption can be minimized by accurately predicting signal strengths and reacting to it in real-time, the dynamic nature of wireless environments makes signal strengths highly unpredictable. In this paper, after analyzing in detail the signal strength variation and its impact on energy consumption, we propose to use crowdsourcing approach to optimize mobile devices’ energy efficiency by utilizing signal strength traces reported/shared by other users/devices in cellular networks. Via a comprehensive measurement study, we observe that signal strength traces collected from different devices are pseudo-identical, and they even exhibit similar threshold-based behaviors in the relationship between signal strength and device power consumption. Based on our observations, we propose a predictive scheduling algorithm that: (i) selects the right set of signal strength traces based on its location, (ii) applies a filter to smooth out signal strengths and hide abrupt changes, (iii) digitizes the signal strength to “good” and “bad” areas, and (iv) schedules transmissions based on power-throughput characteristics to optimize the transmission energy efficiency. To demonstrate the efficacy of the proposed algorithms, we prototype the crowdsourcing-based predicative scheduling algorithm on Android-based smartphones. Our experiment results from real-life driving tests demonstrate that, by leveraging others’ signal traces, mobile devices can save energy up to 35 percent compared to the conventional opportunistic scheduling, i.e., schedule transmissions only based on instantaneous channel conditions.

MEASUREMENTS OF THE THERMAL CONDUCTIVITIES OF SOME COMMONLY USED INSULATING MATERIALS AFTER WETTING

Currently, thermal insulation of buildings is required from both an energy savings perspective and a money savings perspective. Insulation is primarily installed on the outer surface of the buildings. Weather and other circumstances can produce humidity that can act on the building structure, e.g., by changing its heat capacity, the heat transfer coefficient and/or other factors. As a result, it is important to measure the sorption behaviors of the construction materials. To perform sorption measurements, we use a desiccator (Venticell 111 type) to dry the samples and a climatic chamber (Climacell 111 type) to wet the materials. With these two chambers, we can achieve the relevant moisture content of different humidity levels and create a sorption isotherm graph for the sample. During the measurements, four different types of insulations were used (a mineral wool, EPS30, graphite-doped EPS, and yellow colored Extruded Polystyrene).

The Study of Rural Human Settlement Environmental Constructing Situation and Countermeasures of Optimizing of Jilin Province

This article sort out and study on rural construction situation during the past five years in Jilin Province, from the energy-saving perspective, analyzed many factors constraints the sustainable development of rural countryside construction in Jilin Province, and give specific recommendations for improvement measures for future implementation of the integration of urban and rural areas of rural living environment construction.

Impacts of electric rubber-tired gantries on green port performance

Motivated by the need to reduce operating costs and alleviate noise and exhaust pollution generated by cargo handling equipment in container terminals and container yards, this study compares the performance of rubber tired gantries (RTGs) and electric rubber tired gantries (E-RTGs) from the perspective of energy savings and CO2 reduction, and analyzes the impact of E-RTG use on the green port policies of international hub ports.This study discovered that (1) E-RTG cranes offer a significant performance improvement compared with RTGs, and can achieve 86.60% energy savings and a 67.79% reduction in CO2 emissions. (2) ERTG cranes are expected to have an individual payback period of 2.2years, and are not only friendly to the environment, but also ease the impact of diesel oil price hikes. (3) Government may formulate appropriate regulations or provide incentive measures to encourage terminal operators to upgrade their handling equipment or implement E-RTG conversion projects.

A DFuzzy-DAHP Decision-Making Model for Evaluating Energy-Saving Design Strategies for Residential Buildings

The construction industry is a high-pollution and high-energy-consumption industry. Energy-saving designs for residential buildings not only reduce the energy consumed during construction, but also reduce long-term energy consumption in completed residential buildings. Because building design affects investment costs, designs are often influenced by investors’ decisions. A set of appropriate decision-support tools for residential buildings are required to examine how building design influences corporations externally and internally. From the perspective of energy savings and environmental protection, we combined three methods to develop a unique model for evaluating the energy-saving design of residential buildings. Among these methods, the Delphi group decision-making method provides a co-design feature, the analytical hierarchy process (AHP) includes multi-criteria decision-making techniques, and fuzzy logic theory can simplify complex internal and external factors into easy-to-understand numbers or ratios that facilitate decisions. The results of this study show that incorporating solar building materials, double-skin facades, and green roof designs can effectively provide high energy-saving building designs.

Green heterogeneous networks: a cognitive radio idea

From an energy-saving perspective, the authors investigate the downlink power control issue of the two-tier heterogeneous networks (HetNets) using a cognitive radio train of thought. The authors consider the HetNets scenario of one macro-cell evolved-NodeB (eNB) and multiple femto-cell Home evolved NodeBs (HeNBs) cooperatively coexisting to provide better services. A specific HeNB allows macro-mobile station (macro-MS) previously associated with eNB to access to it for better signal-to-interference plus noise ratio (SINR) guarantee. As a reward, the macro-MS pays a certain of revenue to HeNB as the incentive mechanism for this HeNB's downlink extra power consumption, which is manifested in the design of the price function. The throughput bound of Macro-MSs in HeNB cell is given. Then, the authors select the SINR as the performance measure and formulate the power control of selected HeNBs as multi-constrained optimisation problem. Meanwhile, the authors derive the sub-optimal and closed-form power control of individual HeNB, based on which the authors design the distributed algorithm with the aid of eNB and HeNBs cooperatively to implement the pricing information exchange. Simulation results show the improved performance of the convergence, the energy-efficiency measured by ‘energy-per-bit’ and the throughput of the ‘Proposed-Cognitive-x’ power control algorithm.

The toxic and environmental evaluation of pyrolytic liquids by Allium cepa test

In this study, liquid products obtained from the pyrolysis of hazelnut shell (HS), with and without ultra-high molecular weight polyethylene (UHMWPE), were subjected to the Allium cepa test system. Pyrolysis in conjunction with the A. cepa test is a promising technology not only from the perspective of energy savings and a source of precious material, but in terms of the removal of hazardous material from the environment in safe manner. Dosages of pyrolytic liquids dissolved in water were determined according to lethal dose (LD50), with three different solution concentrations. The preparates were dyed with acetocarmine. The mitotic index decreased and chromosomal aberration, especially stickiness and c-mitosis, increased with dosage and time. The addition of UHMWPE to HS in the pyrolysis process resulted in less harmful chemical agents, as observed by the relatively higher mitotic index and lower levels of chromosomal aberration.

The Mechanism and Measures of Adjustment of Industrial Organization Structure: the Perspective of Energy Saving and Emission Reduction

Abstract Based on the theory of scale economies, this paper probes the mechanism and measures of adjusting industrial organization structure to promote energy saving and emission reduction. The structural factors and efficiency factors influencing energy consumption per unit of GDP interact with each other. Among which, the interaction between economies of scale and industrial organization structure constitutes the implementation mechanism that industrial organization structure is adjusted to promote energy saving and emission reduction. The empirical study of energy efficiency of some enterprises in the steel industry in China demonstrates the close relationship between energy efficiency and the scale of enterprises. In the end, measures of adjusting the industrial organization structure are put forward to promote energy saving and emission reduction.

Energetic analysis of fruit juice processing operations in Nigeria

Abstract Energy and exergy studies were conducted in an orange juice manufacturing industry in Nigeria to determine the energy consumption pattern and methods of energy optimization in the company. An adaptation of the process analysis method of energy accounting was used to evaluate the energy requirement for each of the eight defined unit operations. The types of energy used in the manufacturing of orange juice were electrical, steam and manual with the respective proportions of 18.51%, 80.91% and 0.58% of the total energy. It was estimated that an average energy intensity of 1.12 MJ/kg was required for the manufacturing of orange juice. The most energy intensive operation was identified as the pasteurizer followed by packaging unit with energy intensities of 0.932 and 0.119 MJ/kg, respectively. The exergy analysis revealed that the pasteurizer was responsible for most of the inefficiency (over 90%) followed by packaging (6.60%). It was suggested that the capacity of the pasteurizer be increased to reduce the level of inefficiency of the plant. The suggestion has been limited to equipment modification rather than process alteration, which constitutes additional investment cost and may not be economical from an energy savings perspective.