Regulating district heating in Romania: Legislative challenges and energy efficiency barriers

Many states in Eastern and Central Europe (ECE) possess extensive district heating (DH) networks that were constructed during the days of communist rule in order to provide a universally accessible energy service that supported Soviet development policies. But the post-communist transition was marked by the exacerbation of the sector’s numerous technical, economic, regulatory and environmental problems, accompanied by its abandonment in favour of alternative methods of domestic heating. Recent efforts to increase the use of DH in ECE as a result of environmental and energy security concerns have taken place in an absence of critical, context-sensitive research.     

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.     

Analyzing variables for district heating collaborations between energy utilities and industries

One vital means of raising energy efficiency is to introduce district heating in industry. The aim of this paper is to study factors which promote and inhibit district heating collaborations between industries and utilities. The human factors involved showed to affect district heating collaborations more than anything else does. Particularly risk, imperfect and asymmetric information, credibility and trust, inertia and values are adequate variables when explaining the establishment or failure of industry-energy utility collaborations, while heterogeneity, access to capital and hidden costs appear to be of lower importance. A key conclusion from this study is that in an industry-energy utility collaboration, it is essential to nurture the business relationship. In summary, successful collaboration depends more on the individuals and organizations involved in the relationship between the two parties than on the technology used in the collaboration.     

New thinking on the agentive relationship between end-use technologies and energy-using practices

The subject of efficient technologies and how to get them into the homes and hands of users has been at the centre of energy efficiency policy from its inception. What the record shows is that efficient technologies may well increase the efficiency of energy throughput but that promised reductions in energy demand seldom pan out. Confronted with this problem, the usual policy approach has been to work harder to get markets, incentives and information to loosen up the ‘barriers’ to technology penetration. Social scientists have been recruited to facilitate markets with better information and incentives, in other words, to improve the behaviour of energy end-users. The paper argues that both technologists and behaviouralists have oversimplified the ways that technologies and socio-cultural contexts interact to affect energy-using practices. The concept of distributed agency is introduced to capture the theoretical link between technology and behaviour. The examples of air conditioning and food refrigeration are used to illustrate these points.

Conversion of individual natural gas to district heating: Geographical studies of supply costs and consequences for the Danish energy system

Replacing individual natural gas heating with district heating based to increasing shares of renewable energy sources may further reduce CO₂-emissions in the Danish Building mass, while increasing flexibility of the energy system to accommodate significantly larger amounts of variable renewable energy production. The present paper describes a geographical study of the potential to expand district heating into areas supplied with natural gas. The study uses a highly detailed spatial database of the built environment, its current and potential future energy demand, its supply technologies and its location relative to energy infrastructure. First, using a spatially explicit economic model, the study calculates the potentials and costs of connection to expanded district heating networks by supply technology. Then a comprehensive energy systems analysis is carried out to model how the new district heat can be supplied from an energy system with higher shares of renewable energy. It can be concluded on the basis of these analyses that the methods used proved highly useful to address issues of geographically dependent energy supply; however the spatio-economic model still is rather crude. The analyses suggest to expand district heating from present 46% to somewhere in between 50% and 70%. The most attractive potential is located around towns and cities. The study also suggests that CO₂-emissions, fuel consumption and socio-economic costs can be reduced by expanding district heating, while at the same time investing in energy savings in the building mass as well as increased district heating network efficiency.     

A renewable energy system in Frederikshavn using low-temperature geothermal energy for district heating

The Danish city Frederikshavn is aiming at becoming a 100% renewable energy city. The city has a number of energy resources including a potential for off-shore wind power, waste and low-temperature geothermal energy usable as heat source for heat pumps producing district heating.     

Economic optimization and sensitivity analysis of energy requirements in residential space heating

An analytical model which relates performance with costs of additional insulation has been developed and the optimum set of insulation values for the various surfaces of a new building has been determined in a generalized form. On this basis the determinants of the specific energy requirements, corresponding to an optimal level of insulation are identified. The sensitivity of the energy needs to variations in the building structure or design, in the economic conditions, and in the climate characteristics, is also investigated.     

The role of district heating in future renewable energy systems

Based on the case of Denmark, this paper analyses the role of district heating in future Renewable Energy Systems. At present, the share of renewable energy is coming close to 20 per cent. From such point of departure, the paper defines a scenario framework in which the Danish system is converted to 100 per cent Renewable Energy Sources (RES) in the year 2060 including reductions in space heating demands by 75 per cent. By use of a detailed energy system analysis of the complete national energy system, the consequences in relation to fuel demand, CO₂ emissions and cost are calculated for various heating options, including district heating as well as individual heat pumps and micro CHPs (Combined Heat and Power). The study includes almost 25 per cent of the Danish building stock, namely those buildings which have individual gas or oil boilers today and could be substituted by district heating or a more efficient individual heat source. In such overall perspective, the best solution will be to combine a gradual expansion of district heating with individual heat pumps in the remaining houses. Such conclusion is valid in the present systems, which are mainly based on fossil fuels, as well as in a potential future system based 100 per cent on renewable energy.     

Keep that fire burning: Fuel supply risk management strategies of Swedish district heating plants and implications for energy security

Recent decades have seen a strong increase in bioenergy utilization in Sweden, from 52 TWh in 1983 to 128 TWh in 2013. Much of this increase has been achieved by replacing fossil fuels with different forms of bioenergy in district heating. Increased use of bioenergy is generally seen as key to reducing fossil fuel consumption and greenhouse gas emissions and improving energy security.However, replacing fossil fuels with solid biomass fuels in stationary heat and power generation entails significantly more complicated fuel supply logistics, with geographically scattered material associated with storage difficulties and low energy density. Given these risks and challenges and the key role of biomass-based district heating in the Swedish energy system, disturbances in fuel supply to district heating could potentially be an energy security issue.Through literature studies and interviews with employees at 18 district heating plants, we mapped present and future risks and risk management strategies in district heating supply in the Mälardalen region, south-east Sweden. We found that although small disturbances to fuel supply are not uncommon, the likelihood of heat supply failures due to fuel supply problems is low. Risk awareness is generally high among fuel supply managers, with widespread use of multilevel redundancies and diversification as key risk management strategies. However, fuel supply to plants is highly dependent on functioning truck transport and, consequently, availability of diesel fuel for trucks. Risk management can be strengthened further by implementation of forward-looking risk assessments that are less reliant on past experiences.     

The potential of district heating using geothermal energy. A case study, Greece

The purpose of this study is to investigate the possibility of using low-enthalpy geothermal energy from the geothermal field of Sousaki in the province of Korinthos, Greece, to cover the thermal needs of the nearby town of Ag. Theodori. The possibility of developing a system of district heating was examined based on a proposed town model. Total thermal demands were calculated on the basis of a model dwelling and prevailing weather conditions in the area. Subsequently, a heat transfer circuit is proposed, including the distribution network, the heat exchanger, the production and reinjection pumps, and the pumping station. Finally, energy indices are presented, such as demand in tons of equivalent oil and CO₂ emissions.     

Sustainable reference methodology for energy end-use efficiency data in the EU

One of the most important goals of the European energy policy involves the implementation of energy-efficiency measures in large scale so as to promote sustainable development in the European Union (EU) level. The multidimensional character of energy end-use efficiency (EEE) necessitates the collection of a number of related data, apart from the performance and system parameters data, such as socio-economic (e.g., employment, turnover) and Research and Development (R&D) expenditures. Moreover, improved co-ordination of EEE programmes and policies of the community and the member states so as a unified acceptable system to be developed for the monitoring of the EEE data with respect to the existing targets is of significant importance. Even though data-gathering efforts have been implemented, a lot of fragmented data and deduced findings are currently available, which sometimes lack consistency and verification. In this context, the main aim of the paper is to present a sustainable reference methodology for validating EEE data in EU, through the review of existing approaches and methods, defining of most relevant inconsistencies and gaps and provision of recommendations for improvements in EEE data aggregation and statistical interpretation, taking into consideration the related analysis of statisticians, energy technology experts and energy socio-economists.     

Mode selection of China's urban heating and its potential for reducing energy consumption and CO2 emission

China's carbon dioxide (CO₂) emission ranks the highest in the world. CO₂ emission from urban central heating, which has an average annual growth rate of 10.3%, is responsible for 4.4% of China's total CO₂ emission. The current policy for improving urban central heating focuses on replacing coal with natural gas. This paper analyzes the existing situation and problems pertaining to urban heating, and evaluates the potential for reducing energy consumption and CO₂ emission by heat pump heating. The results show that the current policy of replacing coal with natural gas for urban central heating decreases energy consumption and CO₂ emission by 16.6% and 63.5%, respectively. On the other hand, replacing coal-based urban central heating with heat pump heating is capable of decreasing energy consumption and CO₂ emission by 57.6% and 81.4%, respectively. Replacing both urban central and decentralized heating with heat pump heating can lead to 67.7% and 85.8% reduction in energy consumption and CO₂ emission, respectively. The decreases in CO₂ emission will account for 24.5% of China's target to reduce total CO₂ emission by 2020.     

Incentive mechanism design for the residential building energy efficiency improvement of heating zones in North China

Starting with analyzing the investigation results by Ministry of Housing and Urban–Rural Development of China in 2005, more than half of the 10,236 participants are willing to improve the residential building energy efficiency and accept an additional cost of less than 10% of the total cost, the authors illustrate that incenting actions are necessary to improve building energy efficiency and build a central government–local government–market model. As a result of the model analysis, to pursue good execution effects brought by the incentive policies, the executors are required to distinguish the differences of incentive objects’ economic activities and strongly respect the incenting on the energy conservation performance. A case study on the incentive policies of existing residential building energy efficiency improvement in heating zones in North China is given as well. Finally, it is strongly recommended to give the first priority to performance-based incentives so that to reduce the lazy behaviors of the incented objects and ensure the targets to be achieved.     

A model for planning energy requirements for residential heating

A model is presented for planning the energy required for heating residential areas, and a case study where the model has been applied to an urban area in Sweden is discussed. The model has been used as a basis for decisions concerning mainly local and regional energy planning in Sweden. The model is a combined dynamic simulation and optimization model. The results are obtained through optimal balancing of investments in heat supply and energy conservation.     

Low-energy district heating in energy-efficient building areas

This paper presents an innovative low-energy district heating (DH) concept based on low-temperature operation. The decreased heating demand from low-energy buildings affects the cost-effectiveness of traditionally-designed DH systems, so we carried out a case study of the annual energy performance of a low-energy network for low-energy houses in Denmark. We took into account the effect of human behaviour on energy demand, the effect of the number of buildings connected to the network, a socio-economic comparison with ground source heat pumps, and opportunities for the optimization of the network design, and operational temperature and pressure. In the north-European climate, we found that human behaviour can lead to 50% higher heating demand and 60% higher heating power than those anticipated in the reference values in the standard calculations for energy demand patterns in energy-efficient buildings. This considerable impact of human behaviour should clearly be included in energy simulations. We also showed that low-energy DH systems are robust systems that ensure security of supply for each customer in a cost-effective and environmentally friendly way in areas with linear heat density down to 0.20 MWh/(m year), and that the levelized cost of energy in low-energy DH supply is competitive with a scenario based on ground source heat pumps. The investment costs represent up to three quarters of the overall expenditure, over a time horizon of 30 years; so, the implementation of an energy system that fully relies on renewable energy needs substantial capital investment, but in the long term this is sustainable from the environmental and socio-economic points of view. Having demonstrated the value of the low-energy DH concept, we evaluated various possible designs with the aim of finding the optimal solution with regard to economic and energy efficiency issues. Here we showed the advantage of low supply and return temperatures, their effect on energy efficiency and that a DH design that relies on low-temperature operation is superior to a design based on low-flow operation. The total primary energy use in the best design was 14.3% lower than the primary energy use for standard, recently designed networks, and distribution heat losses were halved. Moreover, the exploitation of the entire available pressure by means of careful network design decreased the average pipe size required, which slightly lowers the investment costs for purchasing and laying the pipelines in the ground. This low-temperature DH concept fits the vision of the future energy-sustainable society.     

Achievements and suggestions of heat metering and energy efficiency retrofit for existing residential buildings in northern heating regions of China

In order to promote energy efficiency and emission reduction, the importance of improving building energy efficiency received sufficient attention from Chinese Government. The heat metering and energy efficiency retrofit for existing residential buildings of 0.15 billion m² in northern heating regions of China was initiated in 2007 and completed successfully at the end of 2010. This article introduced the background and outline of the retrofit project during the period of 11th five-year plan. Numerous achievements that received by retrofit such as environmental protection effect, improvement of indoor environment, improvement of heating system, investment guidance effect, promotion of relevant industries and increasing chances of employment were concluded. Valuable experience that acquired from the retrofit project during the period of 11th five-year plan was also summarized in this article. By analyzing the main problems emerged in the past, pertinent suggestions were put forward to promote a larger scale and more efficient retrofit project in the period of 12th five-year plan.     

The demand function for residential heat through district heating system and its consumption benefits in Korea

The demand for residential heat (RH) through a district heating system (DHS) has been and will be expanded in Korea due to its better performance in energy efficiency and the abatement of greenhouse gas emissions than decentralized boilers. The purposes of this paper are two-fold. The first is to obtain the demand function for DHS-based RH in Korea and investigate the price and income elasticities of the demand employing the quarterly data covering the period 1988–2013. The short-run price and income elasticities are estimated as −0.700 and 0.918, respectively. Moreover, the long-run elasticities are −1.253 and 1.642, respectively. The second purpose is to measure the consumption benefits of DHS-based-RH employing the economic theory that they are the sum of the actual payment and consumer surplus for the consumption. Considering that the average price and estimated consumer surplus of the DHS-based RH use in 2013 are computed to be KRW 87,870 (USD 84.1) and KRW 62,764 (USD 60.1) per Gcal, the consumption benefits of the DHS-based RH are calculated to be KRW 150,634 (USD 144.2) per Gcal. This information can be beneficially utilized to conduct an economic feasibility study for a new DHS project related to RH supply.     

The relative competitive positions of the alternative means for domestic heating

This study strives to clarify to what extent the improved insulation of new buildings affects the economically rational choice of heating supply. In the Danish context, natural gas furnaces show to be economically rational for the society only in few cases. District heating should be advocated only for areas with a high concentration of heat demand, primarily areas with apartment buildings. An increased use of heat pumps (HP) should be advocated as the ambient air HP show to be the cheapest of the individual heating systems—and in most cases cheaper than the collective heating systems. The taxation of energy products in relation to space heating should be revised as the economics from the consumer's point of view do not comply with those from the society's point of view.     

A residential end-use energy consumption model for Canada

The residential sector is the third largest end-use energy consumer in Canada. With the increasing pressure on Canada to reduce its energy consumption and the associated carbon dioxide emissions, reducing energy consumption in the residential sector is very important. To quantitatively assess the impact of the large number of measures that can be adopted to reduce the residential energy consumption, a residential energy model for Canada (Canadian Residential Energy End-use Model—CREEM) was developed. This paper presents the model, the characteristics of the residential energy consumption in Canada, and impact of various energy consumption reduction scenarios. © 1998 John Wiley & Sons, Ltd.     

Improving energy efficiency and smart grid program analysis with agent-based end-use forecasting models

Electric utilities and regulators face difficult challenges evaluating new energy efficiency and smart grid programs prompted, in large part, by recent state and federal mandates and financial incentives. It is increasingly difficult to separate electricity use impacts of individual utility programs from the impacts of increasingly stringent appliance and building efficiency standards, increasing electricity prices, appliance manufacturer efficiency improvements, energy program interactions and other factors. This study reviews traditional approaches used to evaluate electric utility energy efficiency and smart-grid programs and presents an agent-based end-use modeling approach that resolves many of the shortcomings of traditional approaches. Data for a representative sample of utility customers in a Midwestern US utility are used to evaluate energy efficiency and smart grid program targets over a fifteen-year horizon. Model analysis indicates that a combination of the two least stringent efficiency and smart grid program scenarios provides peak hour reductions one-third greater than the most stringent smart grid program suggesting that reductions in peak demand requirements are more feasible when both efficiency and smart grid programs are considered together. Suggestions on transitioning from traditional end-use models to agent-based end-use models are provided.