Potential For Energy Efficiency Improvement Research Articles

Long-term U.S transportation electricity use considering the effect of autonomous-vehicles: Estimates & policy observations

In this paper, we model three layers of transportation disruption – first electrification, then autonomy, and finally sharing and pooling – in order to project transportation electricity demand and greenhouse gas emissions in the United States to 2050. Using an expanded kaya identity framework, we model vehicle stock, energy intensity, and vehicle miles traveled, progressively considering the effects of each of these three disruptions. We find that electricity use from light duty vehicle transport will likely be in the 570–1140 TWh range, 13–26%, respectively, of total electricity demand in 2050. Depending on the pace at which the electric sector decarbonizes, this increase in electric demand could correspond to a decrease in LDV greenhouse gas emissions of up to 80%. In the near term, rapid and complete transport electrification with a carbon-free grid should remain the cornerstones of transport decarbonization policy. However, long-term policy should also aim to mitigate autonomous vehicles’ potential to increase driving mileage, urban and suburban sprawl, and traffic congestion while incentivizing potential energy efficiency improvements through both better system management and the lightweighting of an accident-free vehicle fleet.

The remaining potential for energy savings in UK households

Progress on improving energy efficiency of UK homes has stalled in recent years and the question arises how much more potential for further energy savings exist across the housing stock. Whilst there are some high-level estimates of the potential for buildings energy efficiency in the UK, a more granular assessment is needed to understand exactly where this potential lies and what form it takes. Our analysis fills this gap. It is based on the best available evidence on the remaining potential for energy efficiency improvements within UK residential buildings. Using UK government criteria for investment appraisal, we demonstrate that there is a significant resource of untapped energy-saving opportunities in UK homes. Specifically, our estimates suggest that: one quarter of the energy currently used in UK households could be cost effectively saved by 2035; and this could increase to one half if allowance is made for falling technology costs and the wider benefits of energy efficiency improvements. However, these estimates are sensitive to the assumptions made about capital, energy and carbon costs, and capturing this potential will require both significant policy change and large-scale investment.

Energy efficiency improvements of post-combustion CO2 capture based on reactive gas–liquid absorption applied for super-critical circulating fluidized bed combustion (CFBC) power plants

The environmental impact represents a significant constraint for fossil fuel-intensive industrial processes in transition to a low-carbon scenario. This paper is evaluating the potential energy efficiency improvements in reactive gas–liquid absorption process used for CO2 capture from coal-based super-critical CFBC power plants. Two improved configurations for Methyl diethanolamine (MDEA)-based post-combustion CO2 capture were assessed: absorption intercooling and lean vapour recompression as well as the combination of both. The improved MDEA gas–liquid absorption configurations were compared to conventional MDEA and MEA-based systems for post-combustion CO2 capture as well as the CFBC power plant without carbon capture to assess both the energy and cost penalties for CO2 capture. As the results show, the proposed innovative concepts exhibit better specific thermal energy consumptions for solvent regeneration (2.24–2.58 vs. 2.97 MJ/kg CO2), higher net electrical efficiency (34 vs. 32%) and improved economic indicators (e.g. 2403 vs. 2552 €/kW net power as specific capital investment, 39.2 vs. 41.6 €/MWh as O&M costs, 79 vs. 84 €/MWh as cost of electricity) compared to the conventional MDEA and MEA cases.

Electrical energy demand management in Russia

One of the modern and effective tools for energy efficiency improvement at the level of national economies is management of the demand for electrical energy consumption. The mechanism of management of the demand for electrical energy consumption has a significant potential for energy efficiency improvement for the Russian economy, but due to structural features of the Unified Energy System of Russia, the Electrical Energy Demand Management Program is at the stage of concept development. A model of management of the demand for electrical energy consumption for Unified Energy System of Russia has been developed taking into account structural features of the electric power system. Peculiarities of the economic structure of Russia, which influence the formation of the structure of the country’s electric power complex, have been revealed. They were taken into account when developing requirements for the electrical energy demand management system in the Unified Energy System of Russia. The basic features are the multilevel form and hierarchy of the structure; they have been investigated in the process of developing the demand management model. The classification of electric power industry entities, related to processes of electric energy circulation and the influence on the management of the demand for electrical energy consumption, has been developed with economic interests of each entity within the framework of the demand management model. The electrical energy demand management model, which is based on the hierarchical structure of demand management, has been developed and covers the whole complex of management functions and takes into account features of demand management at each management level. The model allows to significantly improve the efficiency of management of the demand for electrical energy consumption, to ensure the quality of management.

Energy Efficiency in Logistics: An Interactive Approach to Capacity Utilisation

Logistics operations are energy-consuming and impact the environment negatively. Improving energy efficiency in logistics is crucial for environmental sustainability and can be achieved by increasing the utilisation of capacity. This paper takes an interactive approach to capacity utilisation, to contribute to sustainable freight transport and logistics, by identifying its causes and mitigations. From literature, a conceptual framework was developed to highlight different system levels in the logistics system, in which the energy efficiency improvement potential can be found and that are summarised in the categories activities, actors, and areas. Through semi-structured interviews with representatives of nine companies, empirical data was collected to validate the framework of the causes of the unutilised capacity and proposed mitigations. The results suggest that activities, such as inflexibilities and limited information sharing as well as actors’ over-delivery of logistics services, incorrect price setting, and sales campaigns can cause unutilised capacity, and that problem areas include i.a. poor integration of reversed logistics and the last mile. The paper contributes by categorising causes of unutilised capacity and linking them to mitigations in a framework, providing a critical view towards fill rates, highlighting the need for a standardised approach to measure environmental impact that enables comparison between companies and underlining that costs are not an appropriate indicator for measuring environmental impact.

Potential energy efficiency improvements for the Brazilian iron and steel industry: Fuel and electricity conservation supply curves for integrated steel mills

The iron and steel sector is the second-largest energy consumer and main emitter of greenhouse gases in the Brazilian industry. We present a unique, detailed analysis of the energy performance of a sample of five integrated mills with internal coke production that account for over half of the crude steel produced in Brazil and identify economically viable energy efficiency measures. The analysis indicates that the specific total energy consumption of this sample of mills increased by about 13% between 2004 and 2014 and that the corresponding figure for electricity consumption was 18%. Performance and cost data on best energy practices for iron and steel production processes applicable in Brazilian mills are used to develop fuel and electricity Conservation Supply Curves. The economic potential identified for fuels was 3.02 GJ/t of crude steel, which can be achieved with nine energy efficiency measures, mainly in the iron making, sintering and steel making processes. The findings also indicate that these mills could become net exporters of electricity with an economic potential of 1.51 GJ/t of crude steel if four energy efficiency measures were implemented, particularly in the O2 production and coke making processes.

A New Concept of Active Demand Side Management for Energy Efficient Prosumer Microgrids with Smart Building Technologies

Energy efficient prosumer microgrids (PMGs) with active and flexible demand side management (DSM) mechanisms are considered to be crucial elements of future smart grids. Due to an increasing share of renewable energy and the growing power demand, appropriate tools to manage not only the loads but also small generation units, heating and cooling systems, storage units and electric vehicles should be provided for them. Therefore, this paper proposes an innovative approach to both physical and logical organization of an active DSM system for future building-integrated prosumer microgrids (BIPMGs), based on standard building automation and control systems (BACS) as well as Internet of Things (IoT) paradigm. New event-triggered control functions with developed universal, logical interfaces for open BACS and IoT network nodes are presented and their implementation in smart metering as well as fully integrated energy management mechanisms is analyzed. Finally, potential energy efficiency improvements with proposed BACS functions are discussed, based on BACS efficiency requirements defined in the EN 15232 standard.

Energy efficiency of Chinese service sector and its regional differences

The energy consumption of the service sector in China is larger than the total energy consumption of Japan, great importance should be attached to the energy efficiency of Chinese service sector. Considering undesirable output and regional heterogeneity, a meta-frontier slack-based efficiency measure (MSBM) approach is adopted in this paper to measure the energy efficiency of Chinese service sector using provincial panel data of China during 1995–2013. The empirical results show that, the energy efficiency of the service sector in China is 0.62 and 0.85 under meta-frontier and group-frontier technologies. The eastern regions show the best performance in energy efficiency, the central region follows and the western region shows the poorest performance. Only the eastern region shows an increasing trend in the energy efficiency of Chinese service sector. The potential of energy efficiency improvement for Hainan, Guizhou, Qinghai, Ningxia, Gansu and Shaanxi are relatively high. Some policy recommendations are proposed to improve the energy efficiency of Chinese service sector.

Utilizing heat sinks for further energy efficiency improvement in multiple heat integrated five-column methanol distillation scheme

Although the potential of energy efficiency improvement of methanol distillation is largely reduced, heats are still in lack of recovery for discharging along with liquid products at embarrassing temperatures. Instead of routinely elevating certain stream temperatures to make a heat source at the cost of other energies. This work suggests an opposite strategy to utilize heat sinks to obtain temperature differences enough for heat recovery. In our former publication, compositions of lower boiling points are observed at the medium pressure column and the atmospheric column, whence make heat sinks available. This facilitates process adjustments for higher heat efficiency: (1) transit the medium column into a preceding atmospheric column, (2) pressured column top vapor distributes heat for thermal integration between bottoms of the light ends column and the preceding atmospheric column, (3) steam condensate from all the reboilers take over 90% heat supply to the former atmospheric column. Compared with the prototype, these changes knock down 31.85% specific stream consumption from 0.919 to 0.697kg (steam)/kg (methanol). Exemplified by the evolution of five-column methanol distillations, the heat sinks strategy adds another train of thought to create heat transfer drive when utilizing low temperature heat for thermal coupling within chemical plant installations.

Analysis of energy efficiency and energy savings potential in China’s provincial industrial sectors

Because industrial sectors in China are energy-intensive, improving energy efficiency and promoting energy savings in these sectors are of great importance for the further sustainable development of China’s economy. Using a proposed meta-frontier data envelopment analysis (DEA), this paper analyzes the total-factor energy efficiency and energy savings potential in China’s provincial industrial sectors for the years 2000–2014 from three perspectives, namely, the technology gap, management, and scale. The results indicate that (1) driven by technological progress, energy efficiency during the sample period was greatly improved, though the expansion of technology gaps between regions and the decline in scale efficiency represented two significant handicaps; (2) the current energy efficiency in China’s industrial sectors remains extremely low, indicating that there is considerable potential for energy efficiency improvement and energy savings; and (3) the sources of energy inefficiency and energy savings potential in China’s industrial sectors exhibit spatially distinct characteristics. Accordingly, it is determined that most of China’s eastern provinces should focus on improving scale and management efficiency, whereas most of its central and western provinces should concentrate on three factors: narrowing the regional technology gap, improving management efficiency, and optimizing the industrial scale.

Load shifting using the heating and cooling system of an office building: Quantitative potential evaluation for different flexibility and storage options

This numerical study evaluates and compares four different flexibility and storage options in building energy systems (batteries, fuel switch, water tanks, and thermal building mass) in terms of potential improvements in load scheduling and energy efficiency. Using a generic modern office building with concrete core conditioning as an example, two different supply concepts (one based on a heat pump, one based on a CHP unit) are considered. A novel hybrid control concept is applied which is designed to be compatible with state-of-the-art controllers implemented in the field. The results show that batteries are the most technically attractive options in terms of grid support, efficiency and ease of implementation. Fuel switch is comparably straightforward to implement, but provides significant benefits only for the considered CHP system. Water tanks with a capacity of about two full operation hours offer nearly the same flexibility as much larger tanks, but negatively influence the efficiency of heat pump systems. The thermal building mass can be used effectively and efficiently for thermal storage, particularly in the heating season, but this is technically challenging to realize. It is shown that current electricity prices do not offer sufficient variations to stimulate grid-supportive operation.

Increasing energy efficiency in passenger ships by novel energy conservation measures

ABSTRACTTo achieve increasing emission requirements, the cruise ship industry is working to develop higher efficiency ships. Cruise ships are different from other ship types in their relatively higher consumption of electrical power, steam and hot water. Several novel high-efficiency system concepts are possible for on-board electrical power generation and other utility services, each with differing impacts and first costs. Low-emission concepts novel to the cruise ship industry include combinations of exhaust gas heat recovery, heat pumps, steam turbines and organic Rankine cycles (ORCs). Yet, evaluation of these concepts is difficult given the different operating modes of cruises, and overall efficiency is dependent on the dynamic operational sequences. In this paper, we compare alternative energy efficiency concepts for cruise ships through simulation studies of the ship operations when equipped with different novel power generation systems. We find that the dual pressure steam systems and ORC offer the greatest potential for energy efficiency improvements in the cruise ship industry. We also find that relatively conventional technologies enable cruise ships to comply with planned upcoming higher ship energy efficiency requirements.

Energy demand for materials in an international context.

Materials are everywhere and have determined society. The rapid increase in consumption of materials has led to an increase in the use of energy and release of greenhouse gas (GHG) emissions. Reducing emissions in material-producing industries is a key challenge. If all of industry switched to current best practices, the energy-efficiency improvement potential would be between 20% and 35% for most sectors. While these are considerable potentials, especially for sectors that have historically paid a lot of attention to energy-efficiency improvement, realization of these potentials under current 'business as usual' conditions is slow due to a large variety of barriers and limited efforts by industry and governments around the world. Importantly, the potentials are not sufficient to achieve the deep reductions in carbon emissions that will be necessary to stay within the climate boundaries as agreed in the 2015 Paris Conference of Parties. Other opportunities need to be included in the menu of options to mitigate GHG emissions. It is essential to develop integrated policies combining energy efficiency, renewable energy and material efficiency and material demand reduction, offering the most economically attractive way to realize deep reductions in carbon emissions.This article is part of the themed issue 'Material demand reduction'.

Improving Energy Efficiency in South Asia

Energy efficiency is considered to be the fastest way to bring additional energy to meet the increasing demand for energy services. Energy efficiency has gained attention in various parts of the world since the 1970s. Contrary to the belief among policy makers that the economic output might suffer due to energy efficiency interventions, it has been shown that higher energy efficiency improves total factor productivity. With an appropriate combination of market instruments and regulations in areas where markets tend to fail, energy efficiency interventions can be successfully implemented. In South Asia, on the supply side of the power systems, the key energy efficiency issues are: (i) the relatively lower efficiency and reliability of thermal power plants, and (ii) the significantly high losses in electricity transmission and delivery systems. On the demand side, opportunities for demand management and conservation are many. There is scope for significant improvement in coal-fired power plant efficiency improvements (2–4 percentage points) and loss reduction in transmission and distribution systems. Indirect demand control mechanisms such as time-of-use electricity tariffs and introduction of appliance standards have been used in South Asia for some time, and they can be enhanced and expanded. Similarly, direct load control through smart metering can also play an important role, with increasing attention now being paid to employment of smart grids in the region. This paper concludes that South Asia has a significant potential for energy efficiency improvement in the power sector. These efficiency improvements can be realized with appropriate policies and programs that can be readily implemented with the existing institutional framework.

A study for improving the energy efficiency of lifts with adjustable counterweighting

This article presents a study of the potential energy efficiency improvement by means of adjusting the lift counterweight. The lift energy consumption in different counterweight set-ups is studied by employing measured lift traffic and energy consumption data from an office building in Finland. Overall, dimensioning the counterweight based on traffic analysis is one of the fastest and most cost-effective means of improving the energy efficiency of lifts. The results from the building imply, however, that with a relatively constant loading throughout the day, the continuous adjusting of the counterweight provides limited energy savings compared to systems where the counterweight is sized according to the average load. Nevertheless, active adjustment of the counterweight size may provide considerable savings in lift systems if there is a wide variation in the car loading between the hours of the day. Furthermore, reducing the counterweight potentially improves the ISO 25745-2 energy efficiency classification of the lift, thus increasing the product attractiveness in the market. Practical application: This article presents practical approaches to analysing the energy consumption of counterbalanced lifts. The modelled results can be used to optimise the mass of the counterweight in order to achieve considerable energy savings in the actual or expected traffic profile.

Beyond Cellular Green Generation: Potential and Challenges of the Network Separation

This article introduces the ideas investigated in the BCG2 project of the GreenTouch consortium. The basic concept is to separate signaling and data in the wireless access network. Transmitting the signaling information separately maintains coverage even when the whole data network is adapted to the current load situation. Such network-wide adaptation can power down base stations when no data transmission is needed and, thus, promises a tremendous increase in energy efficiency. We highlight the advantages of the separation approach and discuss technical challenges opening new research directions. Moreover, we propose two analytical models to assess the potential energy efficiency improvement of the BCG2 approach.

ОЦЕНКА ПОТЕНЦИАЛА ЭНЕРГОСБЕРЕЖЕНИЯ НА ОСНОВЕ ЭНЕРГОАУДИТА

There were presented the findings of the research in energy saving and energy efficiency of public and residential buildings with the purpose of evaluating the energy saving potential on the basis of energy audit. There was demonstrated the nature of energy consumption and the evaluation figures of energy saving in state-financed sphere and housing sector of the country. On the basis of research and calculations of various specialists it was determined, that the highest potential of energy efficiency improvement belongs to the housing funds of the country. It was pointed out that capital repairs and reconstruction of the existing housing funds are the necessary condition of implementing the energy saving measures. The investment issues, their types and their attractiveness for energy saving measures and improving the energy efficiency are reflected.
 

Power Modeling and Exploration of Dynamic and Partially Reconfigurable Systems

Although fairly known for a long time, the vast potential of Dynamic and Partial Reconfigu-ration (DPR) for high energy efficiency is still difficult to exploit, for reasons that are more methodological than purely technical. This work addresses this problem and provides a contri-bution by seeking to improve energy efficient deployment and analysis for embedded hetero-geneous multiprocessor platforms representative of current and upcoming systems. This paper explores the potential energy efficiency improvements of DPR on the concrete implementation of a H.264/AVC video decoder. The methodology used to explore the different implementations is presented and formalized. This formalization is based on pragmatic power consumption models of all the tasks of the application that are derived from real measurements. Results allow to identify low energy / high performance mappings, and by extension, condi-tions at which partial reconfiguration can achieve energy efficient application processing. The improvements are expected to be of 57% in energy and 37% in performance over pure software execution, corresponding also to 16% energy savings over static implementation of the same accelerators for 10% less performance.

The Effectiveness of New Power Generation and Energy Demand Reduction to Achieve Greenhouse Gas Reduction Goals in Building Area

Since the massive power outages that hit across the nation in September 2011, a growing imbalance between energy supply and demand has led to a severe backup power shortage. To overcome the energy crisis which is annually repeated, a policy change for deriving energy supply from renewable energy sources and a demand reduction strategy has become essential. Buildings account for 18% of total energy consumption and have great potential for energy efficiency improvements; it is an area considered to be a highly effective target for reducing energy demand by improving buildings’ energy efficiency. In this regard, retrofitting buildings to promoting environmental conservation and energy reduction through the reuse of existing buildings can be very effective and essential for reducing maintenance costs and increasing economic output through energy savings. In this study, we compared the energy reduction efficiency of national power energy consumption by unit production volume based on thermal power generation, renewable energy power generation, and initial and operating costs for a building retrofit. The unit production was found to be 13,181GWh/trillion won for bituminous coal-fired power generation, and 5,395GWh/trillion won for LNG power generation, implying that LNG power generation seemed to be disadvantageous in terms of unit production compared to bituminous coal-fired power generation, which was attributable to a difference in unit production price. The unit production from green retrofitting increased to 38,121GWh/trillion won due to the reduced energy consumption and benefits of greenhouse gas reduction costs. Renewable energy producing no greenhouse gas emissions during power generation and showed the highest unit production of 75,638GWh/trillion won, about 5.74 times more effective than bituminous coal-fired power generation.

A critical analysis of energy efficiency improvement potentials in Taiwan's cement industry

The cement industry is the second most energy-intensive sector in Taiwan, which underlines the need to understand its potential for energy efficiency improvement. A bottom-up model-based assessment is utilized to conduct a scenario analysis of energy saving opportunities up to the year 2035. The analysis is supported by detailed expert interviews in all cement plants of Taiwan. The simulation results reveal that by 2035, eighteen energy efficient technologies could result in 25% savings for electricity and 9% savings for fuels under the technical diffusion scenario. This potential totally amounts to about 5000 TJ/year, of which 91% can be implemented cost-effectively assuming a discount rate of 10%. Policy makers should support a fast diffusion of these technologies. Additionally, policy makers can tap further saving potentials. First, by decreasing the clinker share, which is currently regulated to a minimum of 95%. Second, by extending the prohibition to build new cement plants by allowing for replacement of existing capacity with new innovative plants in the coming years. Third, by supporting the use of alternative fuels, which is currently still a niche in Taiwan.