Energy use in Denmark

This paper reviews the evolution of energy use in Denmark since the early 1970s, in order to shed light on the future path of energy use in Denmark, with particular emphasis on the role of energy efficiency. Improvements in end-use energy efficiency reduced primary energy requirements in Denmark by 22% between 1972 and 1988. This change accounts for two-thirds of the decline in the ratio of energy use to gross domestic product that occurred during this time: the rest of the decline was caused by changes in the mix of goods and services produced and consumed by the Danes. Total energy savings achieved between 1972 and 1988 in Denmark ranked among the highest measured in any major OECD country. Overall, most of the energy savings in Denmark were brought about through improvements in technology. Short-term changes in consumer behaviour were significant in reducing energy needs for space heating and transport. An important stimulus for improved efficiency was higher energy prices, led in no small part by significant taxes imposed on small consumers of heating oil, electricity and motor fuels.     

The role of new technologies in reducing energy demand

Energy efficiency is often stated to be the most cost-effective measure for satisfying our energy demand with minimal environmental damage. However, the potential energy savings attainable in 'the real world' are frequently overestimated, as is shown in an industrial case study of the glass industry. Nevertheless, there are significant energy savings to be realized, and the role of new technologies in this is important. However, the key to the effective use of new technology for improved energy efficiency is good management and. for best effect, it must be integrated into the normal resource management activities of a company.     

Assessing energy use and greenhouse gas emission savings from compact housing: a small-town case study

Data from the US Department of Energy show that single-family detached homes consume about 17% more energy per year than attached homes and roughly double that of units in large multi-family structures. While greater use of these compact housing types could reduce a community's energy use and greenhouse gas (GHG) emissions, most local climate action plans (CAPs) do not quantify those potential savings. This article describes how the climate action planning process in the Town of Blacksburg, Virginia has addressed residential sector GHG emissions and demonstrates a methodology applied in that community for estimating potential GHG reductions from compact housing. It finds that in an aggressive compact housing scenario GHG emissions from new housing could be decreased by as much as 36%, without factoring in additional energy conservation or efficiency measures. The article concludes with a discussion of the opportunities and challenges related to implementing compact housing in future residential development.     

A demonstration of how virtual meetings can enhance sustainability in a corporate context

Video conferencing (VC) offers benefits to businesses and organizations. A three‐month trial was undertaken across a telecommunications company in Australia to evaluate the use of VC benefits monitoring software to capture data and calculate utilization and business travel savings from air and car travel for individual VC end points across the company. The results from the trial were used by the finance and administration department of the company to promote VC usage and, at the same time, to introduce a nonessential air travel ban, which led to annualized cost savings of up to 40% on business as usual.     

Economic and environmental analysis of standard, high efficiency, rainwater flushed, and composting toilets

The current sanitation technology in developed countries is based on diluting human excreta with large volumes of centrally provided potable water. This approach is a poor use of water resources and is also inefficient, expensive, and energy intensive. The goal of this study was to compare the standard sanitation technology (Scenario 1) with alternative technologies that require less or no potable water use in toilets. The alternative technologies considered were high efficiency toilets flushed with potable water (Scenario 2), standard toilets flushed with rainwater (Scenario 3), high efficiency toilets flushed with rainwater (Scenario 4), and composting toilets (Scenario 5). Cost, energy, and carbon implications of these five design scenarios were studied using two existing University of Toledo buildings. The results showed that alternative systems modeled in Scenarios 2, 4, and 5 were viable options both from an investment and an environmental performance perspective. High efficiency fixtures that use potable water (Scenario 2) is often the most preferred method in high efficiency buildings due to reduced water use and associated reductions in annual water and wastewater costs. However, the cost, energy, and CO(2)EE analyses all showed that Scenarios 4 and 5 were preferable over Scenario 2. Cost payback periods of scenarios 2, 4 and 5 were less than 10 years; in the future, increase in water and wastewater services would further decrease the payback periods. The centralized water and wastewater services have high carbon footprints; therefore if carbon footprint reduction is a primary goal of a building complex, alternative technologies that require less potable water and generate less wastewater can largely reduce the carbon footprint. High efficiency fixtures flushed with rainwater (Scenario 4) and composting toilets (Scenario 5) required considerably less energy than direct energy demands of buildings. However, the annual carbon footprint of these technologies was comparable to the annual carbon footprint from space heating. Similarly, the carbon savings that could be achieved from Scenario 4 or 5 were comparable to a recycling program that can be implemented in buildings.     

Feeding fossil fuels to the soil: An analysis of energy embedded and technological learning in the fertilizer industry

In this paper, we assess energy demand due to fertilizer consumption in the period 1961–2001. Based on historical trends of gross energy requirements, we calculated that in 2001, global energy embedded in fertilizer consumption amounted to 3660 PJ, which represents about 1% of the global energy demand. Total energy demand has increased at an average rate of 3.8% p.a. Drivers behind the trend are rising fertilizer consumption and a shift towards more energy intensive fertilizers. Our results show that despite significant energy efficiency improvements in fertilizer manufacture (with exception of phosphate fertilizer in the last 20 years) improvements in energy efficiency have not been sufficient to offset growing energy demand due to rising fertilizer consumption. Furthermore, we found that specific energy consumption of ammonia and urea developed in close concordance with the learning curve model, showing progress ratios of 71% for ammonia production and 88% for urea. This suggests an alternative approach for including technological change in energy intensive industries in middle and long-term models dealing with energy consumption and CO₂ emissions, while few learning curves exist for energy efficiency of end use technologies.     

Efficient use of energy and materials: progress and policies

There is a growing awareness of the serious problems associated with the provision of sufficient energy to meet human needs and to fuel economic growth world-wide. This has pointed to the need for energy and material efficiency, which would reduce air, water and thermal pollution, as well as waste production. Increasing energy and material efficiency also have the benefits of increased employment, improved balance of imports and exports, increased security of energy supply and adopting environmentally advantageous energy supply. A large potential exists for energy savings through energy and material efficiency improvements. Technologies are not now, nor will they be, in the foreseeable future, the limiting factors with regard to continuing energy efficiency improvements. There are serious barriers to energy efficiency improvements, including unwillingness to invest, lack of available and accessible information, economic disincentives and organizational barriers. A wide range of policy instruments, as well as innovative approaches have been tried in some countries in order to achieve the desired energy efficiency improvements. These include: regulation and guidelines; economic instruments and incentives; voluntary agreements and actions; information, education and training; and research, development and demonstration. An area that requires particular attention is that of improved international co-operation to develop policy instruments and technologies to meet the needs of developing countries. Material efficiency has not received the attention that it deserves. Consequently, there is a dearth of data on the qualities and quantities of final consumption, thus, making it difficult to formulate policies. Available data, however, suggest that there is a large potential for improved use of many materials in industrialized countries.     

Making a stronger case for industrial energy efficiency by quantifying non-energy benefits

This paper describes a more compelling case for industry to promote the non-energy benefits of energy efficiency investments. We do this in two ways to actively appeal to chief executive officers (CEOs) and chief financial officers (CFOs) primary responsibility: to enhance shareholder value. First, we describe the use of a project-by-project corporate financial analysis approach to quantify a broader range of productivity benefits that stem from investments in energy-efficient technologies, including waste reduction and pollution prevention. Second, and perhaps just as important, we present such information in corporate financial terms. These standard, widely-accepted analysis procedures are more credible to industry than the economic modeling done in the past because they are structured in the same way corporate financial analysts perform discounted cashflow investment analyses on individual projects. Case studies including such financial analyses, which quantify both energy and non-energy benefits from investments in energy-efficient technologies, are presented. Experience shows that energy efficiency projects’ non-energy benefits often exceed the value of energy savings, so energy savings should be viewed more correctly as part of the total benefits, rather than the focus of the results. Quantifying the total benefits of energy efficiency projects helps companies understand the financial opportunities of investments in energy-efficient technologies. Making a case for investing in energy-efficient technologies based on energy savings alone has not always proven successful. Evidence suggests, however, that industrial decision makers will understand energy efficiency investments as part of a broader set of parameters that affect company productivity and profitability.     

Modeling Energy Savings from Urban Shade Trees: An Assessment of the CITYgreen® Energy Conservation Module

CITYgreen® software has become a commonly used tool to quantify the benefits of urban shade trees. Despite its frequent use, little research has been conducted to validate results of the CITYgreen energy conservation module. The first objective of this study is to perform a familiar application of CITYgreen software to predict the potential energy savings contribution of existing tree canopies in residential neighborhoods during peak cooling summer months. Unlike previous studies utilizing CITYgreen, this study also seeks to assess the software’s performance by comparing model results (i.e., predicted energy savings) with actual savings (i.e., savings derived directly from energy consumption data provided by the electric utility provider). Homeowners in an older neighborhood with established trees were found to use less energy for air-conditioning than homeowners in a recently developed site. Results from the assessment of model performance indicated that CITYgreen more accurately estimated the energy savings in the highly vegetated, older neighborhood.     

Local or global food markets: A comparison of energy use for transport

This study compares energy use for food transport to a farmers' market in Sweden with energy use for transport in the conventional food system. The farmers' market was investigated through data sampling from on-site investigations. The conventional food system was studied with the aid of life cycle assessments reported in the literature. Overall, the study found no significant differences in levels of energy use for transport to the farmers' market compared with the conventional food system. For certain products, such as fresh fruits and vegetables, transport-related energy use was much lower in the local system although the season in Sweden for this kind of product is restricted to two or three months at the end of the summer. However, there is considerable potential to increase energy efficiency in local food systems by organizing the selling in new ways and by using more energy efficient vehicles.     

Local or global food markets: A comparison of energy use for transport

Abstract

This study compares energy use for food transport to a farmers' market in Sweden with energy use for transport in the conventional food system. The farmers' market was investigated through data sampling from on-site investigations. The conventional food system was studied with the aid of life cycle assessments reported in the literature. Overall, the study found no significant differences in levels of energy use for transport to the farmers' market compared with the conventional food system. For certain products, such as fresh fruits and vegetables, transport-related energy use was much lower in the local system although the season in Sweden for this kind of product is restricted to two or three months at the end of the summer. However, there is considerable potential to increase energy efficiency in local food systems by organizing the selling in new ways and by using more energy efficient vehicles.     

Quantification of potable water savings by residential water conservation and reuse - A case study

To demonstrate the benefits of water conservation at the household level in regional Victoria in Australia, a family house “Sharland Oasis” was designed and built according to an ecologically sustainable design for improved water and energy efficiency. This study has demonstrated that the combined use of alternative water supplies together with water efficient appliances can save up to 77% of total potable water use compared to the average 1990s household water use in the same region considering the location and differing in water use approach. The use of rainwater inside the home alone saved up to 40% of potable water use. In addition to the water savings, there is a significant wastewater discharge saving achieved through the use of water conservation strategies and greywater reuse. A community survey undertaken in regional Victoria revealed that community receptivity for reusing greywater is highest for uses, such as watering gardens and flushing toilets; but it progressively decreased with increasing personal contact with greywater. Positive perception of greywater reuse needs to be encouraged through programs targeted at developing resources, skills and motivation for new water reuse practices and technologies, across a diverse range of social groups.     

Evaluation of energy savings by using high efficiency motors in a thermal power station

This paper presents potential energy savings by installing high-efficiency motors instead of existing ones and their impact on greenhouse gases emissions reductions. This research study of the energy efficiency of electric motors has been performed in a typical thermal power plant. In the literature, the focus has been mainly on separate and away electric motors from operating facilities. The important advantage of this paper over other studies is that it uses the actual motors’ efficiency in the evaluation. The gains both in terms of electrical energy savings and in terms of financial economy by using high-efficiency motors have been discussed. As a result, the energy saving can be expected as 12.6% at the operating rate. This excellent result also reduces greenhouse gas emission by 1,423 tons every year. The analysis of the data provided an overview on energy losses often generated by the degradation and rewinding of electrical motors. This study represents very encouraging results that will help energy managers of industrial plants to become more involved in energy efficiency strategies.     

Lessons from Developing Methods to Study the Relationship of Energy and Water Savings to Housing Conditions and Resident Health

Energy- and water-saving have been promoted as ways of saving money while there has been controversy about the effects (if any) of such measures on resident health. In public housing in the US, energy saving has taken the form of Energy Savings Performance Contracts (ESPC) that pay for renovations out of future savings. In an attempt to test feasibility and pilot research methods we conducted a study of the relationship between gas and water use, exterior heat sensor locations, and basement ventilation with indices developed from resident-reported living conditions and health symptoms in a single housing development. The data sources that we had available to us were not ideal. In particular, we were unable to obtain water use data that coincided in time with our health survey data. Also, we did not have enough surveys in buildings with high water or gas use and had to pool those buildings with other buildings for analysis. Nevertheless, we found several associations between our measures of energy use and resident reports of health symptoms. The associations that we found were generally in the direction that energy and water savings were associated with fewer symptoms and fewer environmental problems. There is a need for studies that obtain better input data but that generally follow the approach we developed.     

Lessons from Developing Methods to Study the Relationship of Energy and Water Savings to Housing Conditions and Resident Health

Abstract

Energy- and water-saving have been promoted as ways of saving money while there has been controversy about the effects (if any) of such measures on resident health. In public housing in the US, energy saving has taken the form of Energy Savings Performance Contracts (ESPC) that pay for renovations out of future savings. In an attempt to test feasibility and pilot research methods we conducted a study of the relationship between gas and water use, exterior heat sensor locations, and basement ventilation with indices developed from resident-reported living conditions and health symptoms in a single housing development. The data sources that we had available to us were not ideal. In particular, we were unable to obtain water use data that coincided in time with our health survey data. Also, we did not have enough surveys in buildings with high water or gas use and had to pool those buildings with other buildings for analysis. Nevertheless, we found several associations between our measures of energy use and resident reports of health symptoms. The associations that we found were generally in the direction that energy and water savings were associated with fewer symptoms and fewer environmental problems. There is a need for studies that obtain better input data but that generally follow the approach we developed.     

Screening of environmental pressure from products in the Swedish railway infrastructure: Implications for strategic environmental management

This paper proposes a method to be used in environmental reviews as an initial tool for estimating upstream environmental pressures from material use in organisations dealing mostly with construction materials. Upstream environmental pressures are often omitted in environmental reviews from organisations and instead tend to be site specific, with a limited life-cycle perspective. This paper uses the Swedish National Rail Authority as a case to present the approach. An energy indicator is used to estimate the environmental pressure of material use.In the studied building project, a small set of products contribute to a major part of the material use and the material-related energy use. The energy use is almost exclusively of nonrenewable energy carriers. The three most important products are all homogenous and non-complex, which makes the energy indicator well suited for the analysis. The organisation can use the results to focus on the most important products and also to see which parts of the organisation contribute to the material-related energy use. Rail traffic in Sweden is almost exclusively from non-fossil-based energy carriers. This highlights the importance of the infrastructure to the overall environmental pressure of the railway. Consequently, if road transport were to shift away from fossil fuels, railways earlier environmental advantages would diminish, since research suggests that railway infrastructure is more energy intensive than road infrastructure.     

Perspective on multi-scale assets for clean energy technologies in buildings

Optimizing high-value energy efficiency and renewable energy in multi-scale systems that include buildings provides energy savings, energy reliability, indoor health and power quality, among other benefits. These benefits are not easily accounted for in traditional energy budget analysis, and their monetization is not included in typical cost-benefit calculations. Popular belief is that higher use of energy efficiency reduces return on investment (ROI) and that inclusion of renewable energy further reduces ROI. In fact, optimization of higher degrees of energy efficiency with on-site renewable has significantly greater positive economics. This is due to several factors including the aging electric grid—statistically having more and longer electric outages—and extremely poor electric power quality (electric surges, sags and transients) that wreaks havoc on digital equipment. Additionally, weather patterns are becoming more intense, stressing the wired electric system and fuel pipelines. As costs for energy efficiency and renewable energy are reduced and as these systems become more standardized and modular, it is more practical to begin utilizing these advances to increase operational resilience and make energy costs more predictable over longer periods.     

GEOTHERMAL ENERGY IN TRANSITION

At a time when future sources of energy are under close scrutiny, both in terms of availability and suitability, geothermal energy ranks among the candidates for inclusion in any appraisal of alternative forms of supply. The use of geothermal energy for the production of electricity and for supplying domestic and industrial heat is a comparatively recent phenomenon, and its application remains closely constrained by favourable geological conditions. Yet exploration in several countries shows that geothermal energy may emerge as an important adjunct to total energy supply in many localities. McNitt outlines some of the economic and technological parameters of this energy source. Small scale geothermal power stations are more economic and less capital intensive than conventional plants, which make them of particular interest for developing countries with small electricity systems and competing demands on limited capital resources. The principal capital expenditures in the development of geothermal sources include exploration, steam production, installation of generating plant and the cost of effluent disposal. The wider use of low grade geothermal heat is also examined, in addition to the environmental problems occurring to the development of geothermal energy. The scope for technical co-operation in the development of geothermal energy is substantial, and it is likely that this source of energy will undergo more intensive development on the local scale in the future.     

The impact of domestic energy efficiency retrofit schemes on householder attitudes and behaviours

Retrofitting existing housing stock to improve energy efficiency is often required to meet climate mitigation, public health and fuel poverty targets. Increasing uptake and effectiveness of retrofit schemes requires understanding of their impacts on householder attitudes and behaviours. This paper reports results of a survey of 500 Kirklees householders in the UK, where the Kirklees Warm Zone scheme took place. This was a local government led city scale domestic retrofit programme that installed energy efficiency measures at no charge in over 50,000 houses. The results highlight key design features of the scheme, socio-economic and attitudinal factors that affected take-up of energy efficiency measures and impacts on behaviour and energy use after adoption. The results emphasise the role that positive feedback plays in reinforcing pro-environmental attitudes and behaviours of participants and in addressing concerns of non-participants. Our findings have implications for the design and operation of future domestic energy efficiency retrofit schemes.     

An energetic life cycle assessment of C&D waste and container glass recycling in Cape Town,South Africa

This study presents the results of a comparative life cycle assessment (LCA) on the energy requirements and greenhouse gas (GHG) emission implications of recycling construction and demolition (C&D) rubble and container glass in Cape Town, South Africa. Cape Town is a medium sized city in a developing country with a growing population and a rising middle class, two factors that are resulting in increased generation of solid waste. The City is constrained in terms of landfill space and competing demands for municipal resources.The LCA assessment was based on locally gathered data, supplemented with ecoinvent life cycle inventory data modified to the local context. The results indicated that recycling container glass instead of landfilling can achieve an energy savings of 27% and a GHG emissions savings of 37%, with a net savings still being achieved even if collection practices are varied. The C&D waste results, however, showed net savings only for certain recycling strategies. Recycling C&D waste can avoid up to 90% of the energy and GHG emissions of landfilling when processed and reused onsite but, due to great dependence on haulage distances, a net reduction of energy use and GHG emissions could not be confidently discerned for offsite recycling. It was also found that recycling glass achieves significantly greater savings of energy and emissions than recycling an equivalent mass of C&D waste.The study demonstrated that LCA provides an important tool to inform decisions on supporting recycling activities where resources are limited. It also confirmed other researchers’ observations that strict adherence to the waste management hierarchy will not always result in the best environmental outcome, and that more nuanced analysis is required. The study found that the desirability of recycling from an energy and climate perspective cannot be predicted on the basis of whether such recycling conserves a non-renewable material. However, recycling that replaces a virgin product from an energy-intensive production process appears to be more robustly beneficial than recycling that replaces a product with little embodied energy. Particular caution is needed when applying the waste management hierarchy to the latter situations.