Modelling and simulation of a distributed power generation system with energy storage to meet dynamic household electricity demand

Electrical consumption in a household is not stable but changeable in one day throughout a whole year. The consumption depends on weather, seasons and users. This characteristic of demand makes it difficult to design and build a distributed power generation system to meet the demand for a household. For this reason, a stand-alone distributed power generation system (DPGS) needs to be carefully designed not only to meet the dynamic household electricity demand, but also to be economical. Hence, for a DPGS, it is essential to utilise electrical energy storage (EES) unit to store the excessive energy while power generation is running at off-peak time; and then the EES may supply the stored energy during the peak demand period. This study investigates a distributed power generation system with an electric energy storage unit to meet the dynamic electricity demand in a household. The system composes of one diesel-engine-generator (DG) running with biofuel; a fuel cell; integrated with an energy storage unit including a supercapacitor and a group of batteries. Models have been set up in Dymola software and two different system configurations are proposed and simulated. The characteristics of the integrated DPGS–EES system are presented and discussed. The results show that both configurations are working properly to meet the demand.     

Analysis of household energy demand in Vietnam

Household energy demand in Vietnam is analysed based on a recent household energy survey in four northern provinces. Energy consumption patterns by fuel type and by end use are analysed. The effects of income on these patterns are also examined for different categories of households. Widely held beliefs about energy use and behaviour have been given actual value.     

Modelling the transport sector fuel demand for developng economies

This paper concentrates on the transport sector of six developing countries with similar common denominators, namely Turkey, Thailand, Pakistan, Morocco, Tunisia and Malaysia. By using standard econometric techniques, we analyse the evolution of oil demand for road transport in these countries in relation to independent variables such as income, population, price of gasoline and diesel etc. Unlike the treatment in the present literature on the subject, gasoline and diesel consumption are estimated separately due to the high share of diesel in the total transport sector consumption. On the basis of the estimation over the period 1970–1990, on a country by country basis, we forecast the demand for these six countries until 2010. The results of this study indicate that the transport sector will be the driving force for energy and oil demand as part of economic growth in these developing countries. Its share in the future energy market structure is expected to grow. Consequently, the (pricing) policies of oil products in this sector have a crucial role for shaping rational economic and energy strategies within the framework of rising environmental concern.     

Modelling of electricity savings in the Danish households sector: from the energy system to the end-user

In this paper, we examine the value of investing in energy-efficient household appliances from both an energy system and end-user perspectives. We consider a set of appliance categories constituting the majority of the electricity consumption in the private household sector, and focus on the stock of products which need to be replaced. First, we look at the energy system and investigate whether investing in improved energy efficiency can compete with the cost of electricity supply from existing or new power plants. To assess the analysis, Balmorel, a linear optimization model for the heat and power sectors, has been extended in order to endogenously determine the best possible investments in more efficient home appliances. Second, we propose a method to relate the optimal energy system solution to the end-user choices by incorporating consumer behaviour and electricity price addition due to taxes. The model is non-exclusively tested on the Danish energy system under different scenarios. Computational experiments show that several energy efficiency measures in the household sector should be regarded as valuable investments (e.g. an efficient lighting system) while others would require some form of support to become profitable. The analysis quantifies energy and economic savings from the consumer side and reveals the impacts on the Danish power system and surrounding countries. Compared to a business-as-usual energy scenario, the end-user attains net economic savings in the range of 30–40 EUR per year, and the system can benefit of an annual electricity demand reduction of 140–150 GWh. The paper enriches the existing literature about energy efficiency modelling in households, contributing with novel models, methods, and findings related to the Danish case.     

Modelling future private car energy demand in Ireland

Targeted measures influencing vehicle technology are increasingly a tool of energy policy makers within the EU as a means of meeting energy efficiency, renewable energy, climate change and energy security goals. This paper develops the modelling capacity for analysing and evaluating such legislation, with a focus on private car energy demand. We populate a baseline car stock and car activity model for Ireland to 2025 using historical car stock data. The model takes account of the lifetime survival profile of different car types, the trends in vehicle activity over the fleet and the fuel price and income elasticities of new car sales and total fleet activity. The impacts of many policy alternatives may only be simulated by such a bottom-up approach, which can aid policy development and evaluation. The level of detail achieved provides specific insights into the technological drivers of energy consumption, thus aiding planning for meeting climate targets. This paper focuses on the methodology and baseline scenario. Baseline results for Ireland forecast a decline in private car energy demand growth (0.2%, compared with 4% in the period 2000–2008), caused by the relative growth in fleet efficiency compared with activity.     

The regional demand for energy by the residential sector in the United States

The residential sector is a substantial consumer of energy in the United States. The heterogeneous composition of the sector complicates modelling the demand for energy. After reflecting the particular nuances introduced by differing thermal characteristics of the various fuels, one finds an income elasticity slightly in excess of unity and a price elasticity of demand of approximately ?0·35. The results are not inconsistent with other studies done for the United States.A translog fuel share model yields some significant and interesting conclusions. Support is lent to the contention that consumers are responding to the relative changes in fuel prices by altering their energy consumption patterns.Finally, the question of stability is addressed. The results are conclusive suggesting that the demand for natural gas, oil and electrical energy have remained cirtually constant over the past three decades.     

Energy-related emissions and mitigation opportunities from the household sector in Delhi

Urban centers are the major consumers of energy, which is a major source of air pollution. Therefore, an insight into energy consumption and quantification of emissions from urban areas are extremely important for identifying impacts and finding solution to air pollution in urban centers. This paper applies the Long-range Energy Alternatives Planning (LEAP) system for modeling the total energy consumption and associated emissions from the household sector of Delhi. Energy consumption under different sets of policy and technology options are analyzed for a time span of 2001–2021 and emissions of carbon dioxide (CO₂), carbon monoxide (CO), methane (CH₄), non-methane volatile organic compounds (NMVOCs), nitrogen oxides (NO_x), nitrous oxide (N₂O), total suspended particulates (TSP) and sulfur dioxide (SO₂) are estimated. Different scenarios are generated to examine the level of pollution reduction achievable by application of various options. The business as usual (BAU) scenario is developed considering the time series trends of energy use in Delhi households. The fuel substitution (FS) scenario analyzes policies having potential to impact fuel switching and their implications towards reducing emissions. The energy conservation (EC) scenario focuses on efficiency improvement technologies and policies for energy-intensity reduction. An integrated (INT) scenario is also generated to assess the cumulative impact of the two alternate scenarios on energy consumption and direct emissions from household sectors of Delhi. Maximum reduction in energy consumption in households of Delhi is observed in the EC scenario, whereas, the FS scenario seems to be a viable option if the emission loadings are to be reduced.     

The energy demand in the manufacturing sector of Pakistan: some further results

The purpose of this study was to re-examine the role of energy in the manufacturing sector of Pakistan using a Partial Equilibrium Approach. GL restricted cost function along with the factor demand equations were estimated using Zellner’s iterative procedure. Higher energy prices do not seem to adversely affect investment in capital. Substitution possibilities between energy and non-energy inputs are very limited and therefore energy price hikes may directly affect the cost of production. Inter-fuel cross price elasticities indicate that there are substitution possibilities between electricity and gas.     

Fuel price determination in transportation sector using predicted energy and transport demand

This study determines fuel price based on estimated sectoral energy and transport demand using pumping prices. Three approaches are first used for estimating energy and transportation demand based on linear time series, polynomial time series and genetic algorithm based (GATEDE and GATDETR), as multi-parameter, models. Then, future fuel prices and marginal costs of the energy consumption are obtained. Transport demand-based energy efficiency methods are also developed. The fuel prices (FP) are analyzed under two scenarios: Linear and exponential price scenarios. Results showed that if the FP increases linearly, the marginal cost will slightly decreases from current trend, but will increases if demand increases exponentially. Results also showed that the demand-based pricing policy would help to develop a new pricing policy for fuel use in order to control fast growing demand on this sector. The exponential price increase would also help to locate financial sources to create environmentally friendly transportation systems.     

Recent development of energy supply and demand in China,and energy sector prospects through 2030

Facing multiple pressures, including its commitment to energy efficiency improvement, the current worldwide recession, and global warming concerns, China is making great efforts to maintain its continuous economic growth and reduce pollutant emissions. Many policies to encourage investing in energy efficiency and renewable energy have been issued. This article provides insights into the latest development of energy production, energy consumption and energy strategic planning and policies in China, and also describes the analysis, carried out by the authors as part of the Asian Energy Security project using the Long-range Energy Alternatives Planning (LEAP) modeling tool, of the impacts of implementing new and expected energy and environmental policies.     

Reduction potentials of energy demand and GHG emissions in China's road transport sector

Rapid growth of road vehicles, private vehicles in particular, has resulted in continuing growth in China's oil demand and imports, which has been widely accepted as a major factor effecting future oil availability and prices, and a major contributor to China's GHG emission increase. This paper is intended to analyze the future trends of energy demand and GHG emissions in China's road transport sector and to assess the effectiveness of possible reduction measures. A detailed model has been developed to derive a reliable historical trend of energy demand and GHG emissions in China's road transport sector between 2000 and 2005 and to project future trends. Two scenarios have been designed to describe the future strategies relating to the development of China's road transport sector. The ‘Business as Usual’ scenario is used as a baseline reference scenario, in which the government is assumed to do nothing to influence the long-term trends of road transport energy demand. The ‘Best Case’ scenario is considered to be the most optimized case where a series of available reduction measures such as private vehicle control, fuel economy regulation, promoting diesel and gas vehicles, fuel tax and biofuel promotion, are assumed to be implemented. Energy demand and GHG emissions in China's road transport sector up to 2030 are estimated in these two scenarios. The total reduction potentials in the ‘Best Case’ scenario and the relative reduction potentials of each measure have been estimated.     

Assessment of demand for natural gas from the electricity sector in India

Electricity sector is among the key users of natural gas. The sustained electricity deficit and environment policies have added to an already rising demand for gas. This paper tries to understand gas demand in future from electricity sector. This paper models the future demand for gas in India from the electricity sector under alternative scenarios for the period 2005–2025, using bottom-up ANSWER MARKAL model. The scenarios are differentiated by alternate economic growth projections and policies related to coal reforms, infrastructure choices and local environment. The results across scenarios show that gas competes with coal as a base-load option if price difference is below US $ 4 per MBtu. At higher price difference gas penetrates only the peak power market. Gas demand is lower in the high economic growth scenario, since electricity sector is more flexible in substitution of primary energy. Gas demand reduces also in cases when coal supply curve shifts rightwards such as under coal reforms and coal-by-wire scenarios. Local environmental (SO₂ emissions) control promotes end of pipe solutions flue gas de-sulfurisation (FGD) initially, though in the longer term mitigation happens by fuel substitution (coal by gas) and introduction of clean coal technologies integrated gasification combined cycle (IGCC).     

Methodologies for representing the road transport sector in energy system models

Energy system models are often used to assess the potential role of hydrogen and electric powertrains for reducing transport CO₂ emissions in the future. In this paper, we review how different energy system models have represented both vehicles and fuel infrastructure in the past and we provide guidelines for their representation in the future. In particular, we identify three key modelling decisions: the degree of car market segmentation, the imposition of market share constraints and the use of lumpy investments to represent infrastructure. We examine each of these decisions in a case study using the UK MARKAL model. While disaggregating the car market principally affects only the transition rate to the optimum mix of technologies, market share constraints can greatly change the optimum mix so should be chosen carefully. In contrast, modelling infrastructure using lumpy investments has little impact on the model results. We identify the development of new methodologies to represent the impact of behavioural change on transport demand as a key challenge for improving energy system models in the future.     

Energy efficiency improvement potentials and a low energy demand scenario for the global industrial sector

The adoption of energy efficiency measures can significantly reduce industrial energy use. This study estimates the future industrial energy consumption under two energy demand scenarios: (1) a reference scenario that follows business as usual trends and (2) a low energy demand scenario that takes into account the implementation of energy efficiency improvement measures. These scenarios cover energy demand in the period 2009–2050 for ten world regions. The reference scenario is based on the International Energy Agency World Energy Outlook (2011 edition) up to 2035 and is extrapolated by Gross Domestic Product projections for the period 2035–2050. According to the reference scenario, the industrial energy use will increase from 105 EJ in 2009 to 185 EJ in 2050 (excluding fuel use as a feedstock). It is estimated that, with the adoption of energy efficient technologies and increased recycling, the growth in industrial energy use in 2050 can be limited to 140 EJ, an annual energy use increase of 0.7 % compared with the 2009 case. The 2050 industrial energy use in the low energy demand scenario is estimated to be 24 % lower than the 2050 energy use in the reference scenario. The results of this study highlight the importance of industrial energy efficiency by providing insights of the energy savings potentials in different regions of the world.     

Modelling the UK residential energy sector under long-term decarbonisation scenarios: Comparison between energy systems and sectoral modelling approaches

The UK government has set a groundbreaking target of a 60% reduction in carbon dioxide (CO₂) emissions by 2050. Scenario and modelling assessment of this stringent target consistently finds that all sectors need to contribute to emissions reductions. The UK residential sector accounts for around 30% of the total final energy use and more than one-quarter of CO₂ emissions. This paper focuses on modelling of the residential sector in a system wide energy–economy models (UK MARKAL) and key UK sectoral housing stock models. The UK residential energy demand and CO₂ emission from the both approaches are compared. In an energy system with 60% economy-wide CO₂ reductions, the residential sector plays a commensurate role. Energy systems analysis finds this reduction is primarily driven by energy systems interactions notably decarbonisation of the power sector combined with increased appliance efficiency. The stock models find alternate decarbonisation pathways based on assumptions related to the future building stock and behavioural changes. The paper concludes with a discussion on the assumptions and drivers of emission reductions in different models of the residential energy sector.     

Modeling global residential sector energy demand for heating and air conditioning in the context of climate change

In this article, we assess the potential development of energy use for future residential heating and air conditioning in the context of climate change. In a reference scenario, global energy demand for heating is projected to increase until 2030 and then stabilize. In contrast, energy demand for air conditioning is projected to increase rapidly over the whole 2000–2100 period, mostly driven by income growth. The associated CO₂ emissions for both heating and cooling increase from 0.8 Gt C in 2000 to 2.2 Gt C in 2100, i.e. about 12% of total CO₂ emissions from energy use (the strongest increase occurs in Asia). The net effect of climate change on global energy use and emissions is relatively small as decreases in heating are compensated for by increases in cooling. However, impacts on heating and cooling individually are considerable in this scenario, with heating energy demand decreased by 34% worldwide by 2100 as a result of climate change, and air-conditioning energy demand increased by 72%. At the regional scale considerable impacts can be seen, particularly in South Asia, where energy demand for residential air conditioning could increase by around 50% due to climate change, compared with the situation without climate change.     

Energy demand and interfuel substitution in the transportation sector

The analysis in this paper is directed at examining the effect of energy prices on the quantity of energy demanded in the transportation sector in the United States. For motor gasoline, the suggestion is that vehicle miles travelled as well as the stock of automobiles respond to changing motor gasoline prices. For other fuels consumed in this sector, the quantity of energy consumed does respond to energy prices as well as the level of economic activity. The magnitude of the response is typically small.     

On the economics of hydrogen from renewable energy sources as an alternative fuel in transport sector in Austria

The core objective of this work is to analyse the possible future relevance of hydrogen from renewable energy sources in the transport sector from an economic point-of-view with special focus on Austria. The analysis is conducted in a dynamic framework until 2050.     

Life-cycle assessment in the renewable energy sector

The Polish energy industry is facing challenges regarding energetic safety, competitiveness, improvement of domestic companies and environmental protection. Ecological guidelines concern the elimination of detrimental solutions, and effective energy management, which will form the basis for sustainable development. The Polish power industry is required to systematically increase the share of energy taken from renewable sources in the total energy sold to customers. Besides the economic issues, particular importance is assigned to environmental factors associated with the choice of energy source. That is where life-cycle assessment (LCA) is important. The main purpose of LCA is to identify the environmental impacts of goods and services during the whole life cycle of the product or service. Therefore LCA can be applied to assess the impact on the environment of electricity generation and will allow producers to make better decisions pertaining to environmental protection. The renewable energy sources analysed in this paper include the energy from photovoltaics, wind turbines and hydroelectric power. The goal and scope of the analysis comprise the assessment of environmental impacts of production of 1 GJ of energy from the sources mentioned above. The study will cover the construction, operation and waste disposal at each power plant. Analysis will cover the impact categories, where the environmental influence is the most significant, i.e. resource depletion, global warmth potential, acidification and eutrophication. The LCA results will be shown on the basis of European and Australian research. This analysis will be extended with a comparison between environmental impacts of energy from renewable and conventional sources. This report will conclude with an analysis of possibilities of application of the existing research results and LCA rules in the Polish energy industry with a focus on Poland's future accession to the European Union. Definitions of LCA fundamental concepts, its methodology and application are described in the ISO 14040-14049 series of standards. These standards have already been introduced in some countries, but in Poland they are still at the stage of translation into Polish. Nevertheless some companies in Poland try to assess how their products influence the environment and what are the possibilities of technology improvement in the existing production process reduce their environmental impact.