scholarly journals Improving the energy efficiency of sparse linear system solvers on multicore and manycore systems

2014 ◽  
Vol 372 (2018) ◽  
pp. 20130279 ◽  
Author(s):  
H. Anzt ◽  
E. S. Quintana-Ortí
Keyword(s):  
Energy Efficiency ◽  
Linear System ◽  
Large Scale ◽  
Energy Performance ◽  
Current Status ◽  
Limiting Factor ◽  
Sparse Linear System ◽  
Sparse Linear Algebra ◽  
Hardware Architectures ◽  
Power And Energy

While most recent breakthroughs in scientific research rely on complex simulations carried out in large-scale supercomputers, the power draft and energy spent for this purpose is increasingly becoming a limiting factor to this trend. In this paper, we provide an overview of the current status in energy-efficient scientific computing by reviewing different technologies used to monitor power draft as well as power- and energy-saving mechanisms available in commodity hardware. For the particular domain of sparse linear algebra, we analyse the energy efficiency of a broad collection of hardware architectures and investigate how algorithmic and implementation modifications can improve the energy performance of sparse linear system solvers, without negatively impacting their performance.

Solving a very large-scale sparse linear system with a parallel algorithm in the Gaia mission

2014 ◽  
Author(s):  
Ugo Becciani ◽  
Eva Sciacca ◽  
Marilena Bandieramonte ◽  
Alberto Vecchiato ◽  
Beatrice Bucciarelli ◽  
...  
Keyword(s):  
Linear System ◽  
Parallel Algorithm ◽  
Large Scale ◽  
Sparse Linear System

scholarly journals Development and Application of a New High-Efficiency Sparse Linear System Solver in the Thermal-Hydraulic System Analysis Code

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Li Ge ◽  
Wei Liu ◽  
Jianqiang Shan
Keyword(s):  
Linear System ◽  
Hydraulic System ◽  
Large Scale ◽  
System Analysis ◽  
High Efficiency ◽  
Oriented Graph ◽  
Lu Factorization ◽  
Analysis Program ◽  
Lower Upper ◽  
Sparse Linear System

This paper presents a faster solver named NRLU (Node Reordering Lower Upper) factorization solver to improve the solution speed for the pressure equations, which are formed by RELAP5/MOD3.3. The NRLU solver uses the oriented graph method and minimal fill-ins rule to reorder the structure of the nonsymmetry sparse pressure matrix. It solves the pressure matrix by LU factorization. Then the solver is embedded into the large scale advanced thermal-hydraulic system analysis program RELAP5/MOD3.3. The comparisons of the original solver and the NRLU solver show that the NRLU solver is faster than the original solver in RELAP5/MOD3.3, and the rate enhancement can be 44.44%. The results also show that the NRLU solver can reduce the number of fill-ins effectively. This can improve the calculation speed.

Building Energy-Efficiency Running Mode of Large-Scale Public Building: Based on Energy Performance Contracting

2011 ◽  
Vol 368-373 ◽  
pp. 3663-3666
Author(s):  
Qi Song ◽  
Xiao Jie Zhang
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Large Scale ◽  
Building Energy ◽  
Energy Performance ◽  
Building Energy Efficiency ◽  
Public Building ◽  
Performance Contracting ◽  
Energy Performance Contracting ◽  
Running Mode

Energy performance contracting plays a key role in improving the building energy-efficiency in China. This paper introduces the current situation of energy-efficiency of large-scale public building in China and provides an overview of energy performance contracting, and then puts forward an innovative energy-efficiency running mode. This paper tries to offer theoretical references for the development of EMC in energy-saving field of large-scale public buildings.

Evaluation of Energy Efficiency in Retrofitting Residential Buildings with Large-Panel Structures

2014 ◽  
Vol 899 ◽  
pp. 24-29 ◽  
Author(s):  
Emanuel Megyesi ◽  
Mariana Brumaru
Keyword(s):  
Energy Efficiency ◽  
Large Scale ◽  
Residential Buildings ◽  
Energy Performance ◽  
Calculation Methods ◽  
East European ◽  
Large Panel ◽  
Before And After ◽  
Reduction Of Co2 ◽  
The Eu

Modular blocks of flats built with large prefabricated panels have become widespread in most of central and East-European countries particularly in the 80es, populating large-scale neighbourhoods. In Romania are representing about 37% of the total fund of apartment blocks, being present in most of the cities. The high percentage of thermal bridges and reduced design thermal resistance of the envelope make these buildings a priority in thermal retrofitting. Using up-to-date calculation methods, the paper presents a thorough analysis of the energy performance of large-panel residential buildings (apartment blocks) before and after renovation. The conclusions are focused on the practical measures to be undertaken for bringing the energy efficiency after retrofitting at the highest possible degree, thus meeting the requirements of the EU legislation and the targets set in the field of energy performance and reduction of CO2 emissions.

scholarly journals Characterising the English school stock using a unified national on-site survey and energy database

2021 ◽  
pp. 014362442110306
Author(s):  
Sung Min Hong ◽  
Daniel Godoy-Shimizu ◽  
Yair Schwartz ◽  
Ivan Korolija ◽  
Anna Mavrogianni ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Large Scale ◽  
Energy Use ◽  
Census Data ◽  
Energy Performance ◽  
Building Stock ◽  
Site Survey ◽  
Property Data ◽  
Operational Energy ◽  
Data Survey

The recent commitment towards a net-zero target by 2050 will require considerable improvement to the UK’s building stock. Accounting for over 10% of the services energy consumption of the United Kingdom, the education sector will play an important role. This study aims to improve the understanding of English primary and secondary schools, using national on-site survey data with several large-scale disaggregate data sources. Property Data Survey Programme (PDSP) data on 18,970 schools collected between 2012 and 2014, Display Energy Certificate (DEC) and school census data from the same period were linked and processed to form a unified schools dataset. Statistical analyses were undertaken on 10,392 schools, with a focus on energy performance, and the relationship to several building and system characteristics. The analyses may point to the possibility of assessing operational energy use of schools in a more disaggregate manner. New datasets with detailed and accurate disaggregate information on characteristics of buildings, such as those used in this study, provide opportunities to develop more robust models of the building stock. Such data would provide an opportunity to identify pathways for reducing carbon emissions effectively and provide lessons for other organisations seeking to achieve significant reductions for achieving climate change goals. Practical Application: Outputs from this study are expected to benefit researchers in various organisations to establish a basis for typical buildings and their performance, facilities managers to assess the operational energy efficiency of school buildings, and relevant public bodies to make informed decisions on improving energy efficiency of the school stock.

scholarly journals Acidification and Nitrogen Eutrophication of Austrian Forest Soils

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Robert Jandl ◽  
Stefan Smidt ◽  
Franz Mutsch ◽  
Alfred Fürst ◽  
Harald Zechmeister ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Forest Soils ◽  
Nitrate Leaching ◽  
Large Scale ◽  
Monitoring Network ◽  
Stand Density ◽  
Current Status ◽  
Limiting Factor ◽  
Climate Change Effects ◽  
Nitrogen Contents

We evaluated the effect of acidic deposition and nitrogen on Austrian forests soils. Until thirty years ago air pollution had led to soil acidification, and concerns on the future productivity of forests were raised. Elevated rates of nitrogen deposition were believed to cause nitrate leaching and imbalanced forest nutrition. We used data from a soil monitoring network to evaluate the trends and current status of the pH and the C : N ratio of Austrian forest soils. Deposition measurements and nitrogen contents of Norway spruce needles and mosses were used to assess the nitrogen supply. The pH values of soils have increased because of decreasing proton depositions caused by reduction of emissions. The C : N ratio of Austrian forest soils is widening. Despite high nitrogen deposition rates the increase in forest stand density and productivity has increased the nitrogen demand. The Austrian Bioindicator Grid shows that forest ecosystems are still deficient in nitrogen. Soils retain nitrogen efficiently, and nitrate leaching into the groundwater is presently not a large-scale problem. The decline of soil acidity and the deposition of nitrogen together with climate change effects will further increase the productivity of the forests until a limiting factor such as water scarcity becomes effective.

Upgrading Energy Efficient Housing and Creating Jobs: It Works Both Ways

2014 ◽  
Vol 39 (2) ◽  
pp. 34-40
Author(s):  
Frits Meijer ◽  
Henk Visscher
Keyword(s):  
Energy Efficiency ◽  
Large Scale ◽  
Housing Stock ◽  
Energy Performance ◽  
Housing Associations ◽  
Building Stock ◽  
Existing Building ◽  
Investment Programme ◽  
The Eu ◽  
New Jobs

The European Commission and EU member states have prioritised the renovation of the existing housing stock as a means of achieving their energy-efficiency targets. As buildings account for 40% of Europe’s energy consumption and much of this is used in the residential sector a major breakthrough could be realized here. Despite the fact that energy saving targets have been prioritized in EU and national policy programme’s, progress is slow. The actual rate and extent of renovations are by fare not enough to achieve the targets. Although the necessity of energy savings is acknowledged by institutional investors in housing, housing associations, individual homeowners and occupants, it appears to be difficult to get sufficient support for energy efficiency renovations. The current economic situation is an additional barrier preventing large scale investments in energy renovating the housing stock. This article connects the realisation of energy efficiency goals with the creation of jobs in the EU. The shift from new-build to renovation will have considerable effects on employment in especially the construction industry and the qualifications required by the workforce. Studies show that for every €1 million investment in the existing building stock in the form of energy renovation work, 12 to 17 new jobs could be created. Potentially this could lead to may new jobs. However, there are many uncertainties in these calculations. Are these direct or indirect jobs, what sectors would benefit, are these jobs created within the EU and what would be the net effect on the labour market? Nonetheless these uncertainties, the positive employment effects will prevail. A new and ambitious investment programme in the housing sector could not only improve the energy performance of the sector but create 100.000’s of valuable jobs at a time when these are seriously needed.

scholarly journals Decarbonising real estate

2020 ◽  
Vol 13 (3) ◽  
pp. 387-408
Author(s):  
Sara Jane Wilkinson ◽  
Sarah Sayce
Keyword(s):  
Energy Efficiency ◽  
Large Scale ◽  
Residential Buildings ◽  
Well Being ◽  
Energy Performance ◽  
Residential Property ◽  
Content Type ◽  
Study Results ◽  
The Relationship

Purpose About 27 per cent of the total UK carbon emissions are attributed to residential buildings; therefore, improvements to the energy efficiency of the stock offers great potential. There are three main ways to achieve this. First is a mandatory approach, minimum energy efficiency standards are set and applied to new and existing buildings. Option 2 is voluntary, using energy ratings that classify performance to stimulate awareness and action. Third, financial measures, incentives and taxes, are applied to “nudge” behaviours. Most westernised countries have adopted a combination of Options 2 and 3, with the belief that the market will incentivize efficient properties. The belief is voluntary measures will stimulate demand, leading to value premiums. This paper aims to seek a deeper understanding of the relationship between energy efficiency and the value of residential property in Europe and, by so doing, to determine whether stronger policies are required to realise decarbonisation. Design/methodology/approach This paper reviews the current academic literature and large-scale quantitative studies conducted in Europe, mostly using hedonic pricing analysis to seek a relationship between energy performance certificates (EPCs) and either capital or rental values. It compares these to the reported findings of three case study projects that take a variety of different research approaches, all of which have the ambition to understand market behaviours and stimulate occupier or/and owner demand for energy efficient buildings. Findings The large-scale academic study results generally show a positive relationship between observed market prices and EPCs, which are commonly taken as surrogates for efficiency; however, outcomes are variable. One large study found energy upgrades may increase value, but not to the point where costs outweigh the value gain. Other studies found high returns on investment in energy efficiency technologies. The case study projects, however, revealed a more nuanced set of arguments in terms of the relationship between energy efficiency and market behaviours. Whilst there is some evidence that energy efficiency is beginning to impact on value, it is small compared to other value drivers; other drivers, including health, well-being and private sector finance deals, may prove more powerful market drivers. Further, the empirical findings reported point towards the emergence of a “brown” discount being more likely to be the long-term trend than a green premium. It is concluded that the current levels of action are unlikely to deliver the levels of decarbonisation urgently needed. Research limitations/implications This is a desktop study of other European studies that may have collected data on slightly different variables. Practical implications This study shows that more action is required to realise decarbonisation in new and existing residential property in the European states considered. The sector offers potential for substantial reductions, and other mandatory approaches need to be considered. Originality/value This is a timely review of the current outcomes of European programmes (EPCs) adopted in several countries to increase energy efficiency in the residential sector through a voluntary mechanism. The results show that more action is needed.

scholarly journals Software and DVFS tuning for performance and energy-efficiency on Intel KNL processors

2018 ◽  
Author(s):  
Enrico Calore ◽  
Alessandro Gabbana ◽  
Sebastiano Fabio Schifano ◽  
Raffaele Tripiccione
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Performance ◽  
Study Strategies ◽  
Limiting Factor ◽  
Xeon Phi ◽  
Clock Frequency ◽  
Trade Offs ◽  
Application Data ◽  
Data Layouts

Energy consumption of processors and memories is quickly becoming a limiting factor in the deployment of large computing systems. For this reason it is important to understand the energy performance of these processors and to study strategies allowing to use them in the most efficient way. In this work we focus on computing and energy performance of the Knights Landing Xeon Phi, the latest Intel many-core architecture processor for HPC applications. We consider the 64-core Xeon Phi 7230, and profile its performance and energy efficiency using both its on-chip MCDRAM and the off-chip DDR4 memory as the main storage for application data. As a benchmark application we use a Lattice Boltzmann code heavily optimized for this architecture, and implemented using several different arrangements of the application data in memory (data-layouts, in short). We also assess the dependence of energy consumption on data-layouts, memory configurations (DDR4 or MCDRAM), and number of threads per core. We finally consider possible trade-offs between computing performance and energy efficiency, tuning the clock frequency of the processor using the Dynamic Voltage and Frequency Scaling (DVFS) technique.

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