Reduction of electricity use in Swedish industry and its impact on national power supply and European CO2 emissions

Decreased energy use is crucial for achieving sustainable energy solutions. This paper presents current and possible future electricity use in Swedish industry. Non-heavy lines of business (e.g. food, vehicles) that use one-third of the electricity in Swedish industry are analysed in detail. Most electricity is used in the support processes pumping and ventilation, and manufacturing by decomposition. Energy conservation can take place through e.g. more efficient light fittings and switching off ventilation during night and weekends. By energy-carrier switching, electricity used for heat production is replaced by e.g. fuel. Taking technically possible demand-side measures in the whole lines of business, according to energy audits in a set of factories, means a 35% demand reduction. A systems analysis of power production, trade, demand and conservation was made using the MODEST energy system optimisation model, which uses linear programming and considers the time-dependent impact on demand for days, weeks and seasons. Electricity that is replaced by district heating from a combined heat and power (CHP) plant has a dual impact on the electricity system through reduced demand and increased electricity generation. Reduced electricity consumption and enhanced cogeneration in Sweden enables increased electricity export, which displaces coal-fired condensing plants in the European electricity market and helps to reduce European CO₂ emissions. Within the European emission trading system, those electricity conservation measures should be taken that are more cost-efficient than other ways of reducing CO₂ emissions. The demand-side measures turn net electricity imports into net export and reduce annual operation costs and net CO₂ emissions due to covering Swedish electricity demand by 200 million euros and 6 Mtonne, respectively. With estimated electricity conservation in the whole of Swedish industry, net electricity exports would be larger and net CO₂ emissions would be even smaller.     

Income and price elasticities of electricity demand: Aggregate and sector-wise analyses

Cointegration and vector error correction modeling approaches are widely used in electricity demand analysis. The study rigorously examines the determinants of electricity demand at aggregate and sectoral levels in Pakistan. In the backdrop of severe electricity shortages, our empirical findings give support to the existence of a stable long-run relationship among the variables and indicate that electricity demand is elastic in the long run to both income and price at aggregate level. At sectoral level, long-run income and price elasticity estimates follow this pattern except in agricultural sector, where electricity demand is found elastic to output but inelastic to electricity price. On the contrary, the coefficients for income and price are rather small and mostly insignificant in the short run. We employed temperature index, price of diesel oil and capital stock at aggregate and sectoral levels as exogenous variables. These variables account for most of the variations in electricity demand in the short run. It shows that mechanization of the economy significantly affect the electricity demand at macro level. Moreover, elastic electricity demand with respect to electricity price in most of the sectors implies that electricity price as a policy tool can be used for efficient use and conservation.     

Optimisation of a Swedish district heating system with reduced heat demand due to energy efficiency measures in residential buildings

The development towards more energy efficient buildings, as well as the expansion of district heating (DH) networks, is generally considered to reduce environmental impact. But the combined effect of these two progressions is more controversial. A reduced heat demand (HD) due to higher energy efficiency in buildings might hamper co-production of electricity and DH. In Sweden, co-produced electricity is normally considered to displace electricity from less efficient European condensing power plants. In this study, a potential HD reduction due to energy efficiency measures in the existing building stock in the Swedish city Linköping is calculated. The impact of HD reduction on heat and electricity production in the Linköping DH system is investigated by using the energy system optimisation model MODEST. Energy efficiency measures in buildings reduce seasonal HD variations. Model results show that HD reductions primarily decrease heat-only production. The electricity-to-heat output ratio for the system is increased for HD reductions up to 30%. Local and global CO₂ emissions are reduced. If co-produced electricity replaces electricity from coal-fired condensing power plants, a 20% HD reduction is optimal for decreasing global CO₂ emissions in the analysed DH system.     

Effects of demand side management on Chinese household electricity consumption: Empirical findings from Chinese household survey

China’s residential electricity demand has grown rapidly over the last three decades and given the expected continued growth, demand side management (DSM) can play an important role in reducing electricity demand. By using micro-level data collected from 1450 households in 27 provinces in the first-ever China Residential Energy Consumption Survey in 2012, this study estimates the effects of three DSM measures empirically: tiered household electricity pricing, China Energy Label program, and information feedback mechanisms. We find these measures have contributed to moderating residential electricity demand growth but additional policy reform and tools are needed to increase their effectiveness and impact. Residential electricity demand is found to be price- and income- inelastic and tiered pricing alone may not be as effective in electricity conservation. The statistically significant relationship between China Energy Label efficient refrigerators - but not televisions - and lowered residential electricity consumption reflect mixed program effectiveness. Lastly, of the information feedback currently available through electricity bills, payment frequency and meters, only meter reader is estimated to be statistically significant. Important policy implications and recommendations for improving each of these three DSM measures to expand their impact on reducing residential electricity consumption are identified.     

Residential past and future energy consumption: Potential savings and environmental impact

In order to identify main drivers behind changes in electricity and fuel consumptions in the household sector in Jordan, two empirical models are developed based on multivariate linear regression analysis. In addition, this paper analyzes and evaluates impacts of introducing some efficient measures, such as high efficiency lightings and solar water heating systems, in the housing stock, on the future fuel and electricity demands and associated reduction in GHG emissions. It was found that fuel unit price, income level, and population are the most important variables that affect demand on electrical power, while population is the most important variable in the case of fuel consumption. Obtained results proved that the multivariate linear regression models can be used adequately to simulate residential electricity and fuel consumptions with very high coefficient of determination. Without employing most effective energy conservation measures, electricity and fuel demands are expected to rise by approximately 100% and 23%, respectively within 10 years time. Consequently, associated GHG emissions resulting from activities within the residential sector are predicted to rise by 59% for the same period. However, if recommended energy management measures are implemented on a gradual basis, electricity and fuel consumptions as well as GHG emissions are forecasted to increase at a lower rate.     

Scenarios for the evolution of the Spanish electricity sector: Is it on the right path towards sustainability?

The Spanish energy and electricity models are clearly unsustainable: the large increase in electricity demand, a huge dependency on energy imports, and significant environmental impacts are clear reasons for concern. In this paper we take a look at the possible evolution of the Spanish electricity sector under different policy scenarios, and try to identify which are the policies that may help to achieve the desired goal, as well as the role that the different technologies may play. Results are quite optimistic in that, under the appropriate policy measures, carbon emissions of the electricity sector may be reduced in 2020 up to 37% compared to 1990, and energy imports may be also much reduced, at reasonable costs. However, this may only be achieved by strongly pursuing energy efficiency improvements and other energy conservation measures, which should then become a must for all energy plans in Spain, together with renewable energy promotion and stronger carbon reduction policies.     

Energy efficiency in the British housing stock: Energy demand and the Homes Energy Efficiency Database

The UK Government has unveiled an ambitious retrofit programme that seeks significant improvement to the energy efficiency of the housing stock. High quality data on the energy efficiency of buildings and their related energy demand is critical to supporting and targeting investment in energy efficiency. Using existing home improvement programmes over the past 15 years, the UK Government has brought together data on energy efficiency retrofits in approximately 13 million homes into the Homes Energy Efficiency Database (HEED), along with annual metered gas and electricity use for the period of 2004–2007.This paper describes the HEED sample and assesses its representativeness in terms of dwelling characteristics, the energy demand of different energy performance levels using linked gas and electricity meter data, along with an analysis of the impact retrofit measures has on energy demand. Energy savings are shown to be associated with the installation of loft and cavity insulation, and glazing and boiler replacement. The analysis illustrates this source of ‘in-action’ data can be used to provide empirical estimates of impacts of energy efficiency retrofit on energy demand and provides a source of empirical data from which to support the development of national housing energy efficiency retrofit policies.     

MODEST-An energy-system optimisation model applicable to local utilities and countries

MODEST, an energy-system optimisation model is described. It has been applied to a typical local Swedish electricity and district-heating utility and to the national power system. Present and potential installations and energy flows should be considered and their best combination can be obtained through optimisation. MODEST uses linear programming to minimise the capital and operation costs of energy supply and demand-side management. Seasonal, weekly, and diurnal variations of, for example, demand, costs, and capacities are considered. MODEST may be used to decide which investments to make, the dimensioning of new installations, and the operation of all system components. The municipal utility under study should now expand its heat production using woodchips. Electricity export or nuclear phase-out will probably raise the Swedish electricity prices. In this case, cost minimisation is achieved by introducing combined heat and power (CHP) production in the municipality. Fossil fuels should be used in the cogeneration plant at current taxation levels but biofuels are favourable if higher environmental fees are imposed for CO₂ emissions. Biomass capacity expansion could decrease local CO₂ emissions by 80%. Efficiency improvements for electricity use have robust profitability at high electricity prices. The Swedish electricity demand may be satisfied without nuclear power and fossil fuels through massive biomass use, wind-power supply, and energy conservation.     

Plug-in hybrid vehicle GHG impacts in California: Integrating consumer-informed recharge profiles with an electricity-dispatch model

This paper explores how Plug-in Hybrid Vehicles (PHEVs) may reduce source-to-wheel Greenhouse Gas (GHG) emissions from passenger vehicles. The two primary advances are the incorporation of (1) explicit measures of consumer interest in and potential use of different types of PHEVs and (2) a model of the California electricity grid capable of differentiating hourly and seasonal GHG emissions by generation source. We construct PHEV emissions scenarios to address inherent relationships between vehicle design, driving and recharging behaviors, seasonal and time-of-day variation in GHG-intensity of electricity, and total GHG emissions. A sample of 877 California new vehicle buyers provide data on driving, time of day recharge access, and PHEV design interests. The elicited data differ substantially from the assumptions used in previous analyses. We construct electricity demand profiles scaled to one million PHEVs and input them into an hourly California electricity supply model to simulate GHG emissions. Compared to conventional vehicles, consumer-designed PHEVs cut marginal (incremental) GHG emissions by more than one-third in current California energy scenarios and by one-quarter in future energy scenarios—reductions similar to those simulated for all-electric PHEV designs. Across the emissions scenarios, long-term GHG reductions depends on reducing the carbon intensity of the grid.     

Net benefits of energy conservation in housing

The computer program FREDOCAN allows one to assess the impact of energy conservation policies on the household sector due to thermal insulation measures and to various options concerning domestic heating plants. the insulation policy must be specified, giving in input to the program the housing stock and the fraction of dwellings to be insulated as a function of time. the different insulation measures are evaluated both separately and in a combined way. the evaluations are performed both from financial and energy analysis point of view, determining the internal rates of return of the investments, financial and energy pay-back times under static and dynamic conditions. The space heat savings evaluated in the first part of the program allow one to calculate, in the second part, additional savings due to the reduction of the investments required for the heating plants. It is also possible to assess the variation with time of the heating plant mix, taking into account of improved efficiencies and different energy sources. A test case for the North of Italy is described. It shows that a very simple insulation of both existing and new houses limits the growth of energy demand to only 18 per cent above the 1977 consumption levels, although the combined effects of new constructions and of an extensive upgrading of heating systems would require a 75 per cent energy demand increase.     

Effect of apartment building energy renovation on hourly power demand

ABSTRACT

Optimal energy renovations of apartment buildings in Finland have a great impact on annual energy demand. However, reduction of energy demand does not necessarily translate into similar changes in peak power demand. Four different types of apartment buildings, representing the Finnish apartment building stock, were examined after optimal energy retrofits to see the influence of retrofitting on hourly power demand. Switching from district heating to ground-source heat pumps reduced emissions significantly under current energy mix. However, the use of ground-source heat pumps increased hourly peak electricity demand by 46–153%, compared to district heated apartment buildings. The corresponding increase in electrical energy demand was 30–108% in the peak month of January. This could increase the use of high emission peak power plants and negate some of the emission benefits. Solar thermal collectors and heat recovery systems could reduce purchased heating energy to zero in summer. Solar electricity could reduce median power demand in summer, but had only a little effect on peak power demand. The reduction in peak power demand after energy retrofits was less than the reduction in energy demand.     

Substitution of petroleum products in Brazil Urgent issues

Brazilian energy policy in recent years has focused on curbing demand for imported petroleum by fostering conservation and substitution with domestic energy resources. These measures have resulted in substantial surpluses of both gasoline and fuel oil, thereby weakening the case for continued subsidization of alternatives to those fuels. The pace of oil substitution must be revised and policies reassessed. The areas deserving the highest priority are the cost and productivity of ethanol (alcohol fuel) production, electricity tariffs, motor fuel policy, and the role of fuel oil in industrial energy demand.     

Building stock dynamics and its impacts on materials and energy demand in China

China hosts a large amount of building stocks, which is nearly 50 billion square meters. Moreover, annual new construction is growing fast, representing half of the world's total. The trend is expected to continue through the year 2050. Impressive demand for new residential and commercial construction, relative shorter average building lifetime, and higher material intensities have driven massive domestic production of energy intensive building materials such as cement and steel. This paper developed a bottom-up building stock turnover model to project the growths, retrofits and retirements of China's residential and commercial building floor space from 2010 to 2050. It also applied typical material intensities and energy intensities to estimate building materials demand and energy consumed to produce these building materials. By conducting scenario analyses of building lifetime, it identified significant potentials of building materials and energy demand conservation. This study underscored the importance of addressing building material efficiency, improving building lifetime and quality, and promoting compact urban development to reduce energy and environment consequences in China.     

Heat planning for fossil-fuel-free district heating areas with extensive end-use heat savings: A case study of the Copenhagen district heating area in Denmark

The Danish government plans to make the Danish energy system to be completely free of fossil fuels by 2050 and that by 2035 the energy supply for buildings and electricity should be entirely based on renewable energy sources. To become independent from fossil fuels, it is necessary to reduce the energy consumption of the existing building stock, increase energy efficiency, and convert the present heat supply from fossil fuels to renewable energy sources. District heating is a sustainable way of providing space heating and domestic hot water to buildings in densely populated areas. This paper is a theoretical investigation of the district heating system in the Copenhagen area, in which heat conservation is related to the heat supply in buildings from an economic perspective. Supplying the existing building stock from low-temperature energy resources, e.g. geothermal heat, might lead to oversized heating plants that are too expensive to build in comparison with the potential energy savings in buildings. Long-term strategies for the existing building stock must ensure that costs are minimized and that investments in energy savings and new heating capacity are optimized and carried out at the right time.     

Climate-related electricity demand-side management in oil-exporting countries—the case of the United Arab Emirates

The oil crisis of the 1970s has increased the concern about the continuity of oil imports flow to major oil-importing developed countries. Numerous policy measures including electricity demand-side management (DSM) programs have been adopted in such countries. These measures aim at reducing the growing need for electricity power that increases the dependency on imported foreign oil and damages the environment. On the other hand, the perception that energy can be obtained at very low cost in oil-rich countries led to less attention being paid to the potential of DSM policies in these countries. This paper discusses such potential using the case of the United Arab Emirates (UAE). Since air conditioning is a major source of electric energy consumption, the relationship between climate conditions and electric energy consumption is considered. An electricity demand model is constructed using time series techniques. The fitted model seems to represent these relationships rather well. Forecasts for electricity consumption using the estimated model indicate that a small reduction in cooling degrees requirement might induce a significant reduction in electric energy demand. Hence, a DSM program is proposed with policy actions to include, among others, measures to reduce cooling degrees requirement.     

Automated prediction system of household energy consumption in cities using web crawler and optimized artificial intelligence

The supply of electrical energy is critical to convenient and comfortable living. However, people consume a large amount of energy, contributing to an energy crisis and global warming, and damaging some ecological cycles. Residential electricity consumption has greater elasticity than industrial and business consumption; it therefore has high energy-saving potential. This work establishes an automated platform, which provides information about residential electricity consumption in each city in Taiwan. Machine learning was used to forecast future residential electricity demand. A nature-inspired optimization method was applied to enhance the accuracy of the best machine learner, yielding an even better hybrid ensemble model. Performance measures indicate that the resulting model is accurate and provides effective information for reference. An automatic web-based system based on the model was combined with a web crawler and scheduled to run automatically to provide information on monthly residential electricity consumption in each county and city. By providing energy consumption information across the country, power providers and government can discuss policy and set different goals for energy use. The results of this study can facilitate the early implementation of energy-saving and carbon emission-reducing in cities and aid utility companies in establishing energy conservation guidelines.     

Application of Life Cycle Assessment (LCA) and extenics theory for building energy conservation assessment

Reduce energy consumption and environmental pollution is an important objective in energy sustainability. The building sector, one of the fastest growing in terms of energy consumption, accounts for over 40% of final energy. Building energy conservation will drive the application of new energy conservation technologies and strongly promote the development of sustainable building. In this paper, the extenics theory and life cycle assessment (LCA) are proposed in building energy conservation assessment. Analytic hierarchical process (AHP) method and 9-scale pair-wise comparison are adopted to determine the weights of the factors in different hierarchies. A building energy conservation assessment model combining LCA and the extenics theory is established. The matter-element and the dependent function are defined. Then the synthesis dependent degree and the final grade index are calculated. Thus the building energy conservation grade is obtained. An example is used to illustrate the proposed approach. The results provide guidance to assess building energy conservation performance and determine the energy conservation grade of buildings.     

Evaluation of city-scale impact of residential energy conservation measures using the detailed end-use simulation model

Energy conservation policies for the residential sector are evaluated by a model that simulates city-scale energy consumption in the residential sector by considering the diversity of household and building types. In this model, all the households in the city are classified into 380 categories based on the household and building type. The energy consumption for each household category is simulated by the dynamic energy simulation model, which includes an energy use schedule model and a heating and cooling load calculation model. Since the energy usage of each appliance is simulated for every 5 min according to the occupants’ energy usage activity, this model can evaluate not only the energy conservation measures by improving the buildings and appliances but also the measures that involve changing the occupants’ activities. The accuracy of the model is verified by comparing its results with the statistical and the measured data on Osaka City, Japan. Various types of energy conservation measures planned by the Japanese government for the residential sector are simulated and their effects on Osaka City are evaluated quantitatively. The future effects of these combined measures on the energy consumption are also predicted.     

Residential energy demand in the United States: Analysis using static and dynamic approaches

The residential sector is the main consumer of energy in the United States, and reducing energy consumption is an important goal for policymakers in each state. To know how reducing residential energy demand could be achieved, this study develops a set of static and dynamic models to investigate and identify the impact of socio-economic and demographic characteristics, building age, energy prices, and weather conditions on residential energy demand at the state level from 2005 to 2013. Next, this study proposes two alternative scenarios to reduce residential energy demand based on the most precise model. For every 10,000 dollars of per capita income in each state: (1) increasing residential electricity price by 1 cent per kW h and (2) decreasing average building age by 1%. In the first scenario, the findings indicate that annual residential electricity demand would decrease by 7.3% on average, with the highest reductions in Washington (11.9%), North Dakota (10.9%), and Idaho (9.7%). In the second scenario, residential gas demand would decrease by an average of 15.8% annually, with the highest reduction in Connecticut (33.2%) followed by New York (33.0%) and Massachusetts (30.7%). These proposed scenarios assist policymakers in optimizing decisions and investments to reduce residential energy consumption.     

A comprehensive investigation of a low-energy building in Sweden

In Sweden, the building sector alone accounts for almost 40% of the total energy demand and people spend more than 80% of their time indoors. Reducing energy demand in the buildings is essential to the achievement of a sustainable built environment. At the same time, it is important to not deteriorate people's health, well-being and comfort in buildings. Thus, designing healthy and energy efficient buildings are one of the most challenging tasks for building scientists. A low-energy building that uses less than half of the purchased energy of a comparable typical Swedish building has been investigated from different viewpoints in an attempt to represent the building at different system levels. First, the ventilation performance in different rooms using the tracer gas method is reported. Second, results from simulations and in situ measurements are used to analyse the building's power demand and energy performance. The household's behaviour and their impact on energy usage as well as acceptance are reported. Finally, the CO₂ emissions with regard to the energy usage are analysed on the basis of different supply energy forms from surrounding energy systems, for example a Swedish and European electricity mix, or district heating as a substitute for electrical heating.