National Energy Balance Research Articles

Predicting Heat Demand for a District Heating Systems

Poland is one of the heaviest users of district heating systems in Europe, and those district heating systems are heated mainly by coal. Sustainable development of district heating systems in Poland including improving quality of environment, economic of heat production and security of heat supply is in close connection with increasing of energy efficiency. Heat production and heat distribution plays important role in national energy balance. Additional increasing of energy efficiency in district heating systems need detail forecasts for future heat consumption in scale of individual district heating system and for systems in whole country. Accurate forecast give possibility for increasing efficiency of heat production, decreasing fuel consumption and connected with it emission decreasing from combustion products to the atmosphere. Heat production efficiency can be optimized through the use of appropriate procedures for running heat sources alongside short-term heat demand forecasting combined with preparation for adjusting heat source work parameters to the predicted heat load for a few hours hence. The artificial neural networks model delivers good forecasting results. The accuracy of the results depends on the kind of network, its architecture, the size and type of input data as well as the forecasting period. Forecasting accuracy within a 3-5% margin of error is sufficient to steer heat source operations. Described forecasting methods can be use as a good tool to regulate district heating networks and heat sources.

Characterization of thermal performance and nominal heating gap of the residential building stock using the EPBD-derived databases: The case of Portugal mainland

This work explores the potential of the energy certificates databases, established in EU countries after the EPBD, to characterize the Energy Performance of the residential building stock and the gap between the nominal needs and the actual energy use from the national energy balances, using Portugal mainland as case-study. It also assesses the impact of Portuguese regulations on the thermal quality of the housing building stock through time. The results confirm the viability, usefulness and richness of using the EPBD-derived databases. In the specific case of Portugal they show a mix of natural improvement with boosts from regulations, with crucial developments observed after 2006, reflecting the positive impact of the EPBD. Furthermore, it was concluded that the actual energy use for space heating and for domestic hot water are only 5% and 22%, respectively, of those obtained from the RCCTE reference/“nominal” calculation conditions, with the difference constituting what is here called as the “nominal heating gap”.

The electric energy potential of landfill biogas in Brazil

The increases in a country's energy capacity are related to its gross domestic product (GDP). In Brazil, increases in income and the consumption of goods and services have led to an increase in the generation of solid waste (SW), which is sent to landfills as a method of treatment and final disposal. The purpose of this study was to facilitate an increase in energy generation from renewable resources, specifically from landfills via thermal biogas plants, and the research was divided into two phases. The first phase involved the assessment of the potential population size contributing to the landfill, which could result in the installation of a financially viable enterprise to generate electricity in Brazil. Next, an estimate of the costs associated with the generation and collection of solid waste in Brazil was predicted by GDP prognoses, the latter being in accordance with the National Energy Balance (Balanço Energético Nacional – BEN) plan created by the Mines and Energy Ministry of Brazil (Ministério de Minas e Energia do Brasil – MME). The net present value (NPV) and internal rate of return (IRR) of each enterprise scenario was used in the first stage to assess the plan's financial viability. In the second stage, estimation curves such as logistics, decreasing rate of growth, and logarithmic curves were used to establish relationships between the generation scenarios and the projected collection of SW and projected GDP. Thus, a range of possible landfill biogas/methane generation values and installed energy capacities were created, considering the extreme maximum and minimum values. These values were related to the energy sources from residual fuels reported by BEN. The results demonstrated that such values still represented a small percentage (0.00020% in 2010 and 0.44496–0.81042% in 2030) of the projected energy generation from residual fuels. Thus, an urgent need was identified to formulate policies that would encourage landfills as a source of renewable energy, broadening the number of financially viable initiatives for energy generation from landfill biogas for populations of fewer than 200,000 inhabitants.

Assessing the PV business opportunities in Greece

Greece, as a member of the European Union (EU), has undertaken the obligation to meet the expected goals for the penetration of Renewable Energy Sources (RES) in the national energy balance in compliance with “20–20–20” goals (20% of the Gross Energy Consumption and 40% of the Gross Electricity Consumption should be covered by RES). Although the development of RES, and particularly of Photovoltaic (PV), in Greece during the last years has presented a satisfactory growth, the country is still far away from the above goals. The main reason for this delay is that – except the financial crisis – many licenses are inactive and waiting funding in order to be utilized. Additionally, the latest law (L.4152/2013) has forbidden the interconnection of new PV power Plants to the grid until the end of 2013. The above fact determines the significance of the existing PV Licenses in achieving the national goals. The aim of this paper is to present an integrated approach of qualitative judgments for the PV business opportunities through the assessing of the licenses’ value in Greece. The approach, which is based on a Multi Criteria Decision Making (MCDM) theory of quantifying multiple qualitative judgments, takes into account the real factors which can affect the expected production and cost of the PV installation and therefore the RoI (Return of Investment).

Electricity Smart Meters Interfacing the Households

The recent worldwide measures for energy savings call for a larger awareness of the household energy consumption, given the relevant contribution of domestic load to the national energy balance. On the other hand, electricity smart meters together with gas, heat, and water meters can be interconnected in a large network offering a potential value to implement energy savings and other energy-related services, as long as an efficient interface with the final user is implemented. Unfortunately, so far, the interface of such devices is mostly designed and addressed at the utilities supervising the system, giving them relevant advantages, while the communication with the household is often underestimated. This paper addresses this topic by proposing the definition of a local interface for smart meters, by looking at the actual European Union and international regulations, at the technological solutions available on the market, and at those implemented in different countries, and, finally, by proposing specific architectures for a proper consumer-oriented implementation of a smart meter network.

Challenges and opportunities in accounting for non-energy use CO2 emissions: an editorial comment

The combustion of fossil fuels for energy purposes is by far the most significantcontributor to anthropogenic greenhouse gas (GHG) emissions. However, fossilfuels also contribute to GHG emissions via so-called “non-energy” (i.e., productfeedstock) uses by the global chemicals and petroleum refining industries. Theseemissions, which are often referred to as non-energy use carbon dioxide (NEU-CO2)emissions, represent a significant and potentially growing source of global GHGemissions.Simply described, NEU-CO2 emissions are generated via two primary mecha-nisms. First, oxidation can occur during production, conversion, use, and treatmentprocesses related to certain chemical and refinery products. Important examplesinclude: oxidation during steam cracking in ethylene production and steam reformingin ammonia production; use phase oxidation of products such as solvents, lubricants,urea fertilizers, and solid carbon for metals manufacture; and oxidation of surfactantsand fossil carbon residues during facility wastewater treatment operations.Second, a fraction of the carbon contained in feedstock fuels can be released viacombustion during incineration or energy recovery processes applied to chemicalby-products in various chemical plant and refinery operations. Data permitting,NEU-CO2 emissions arising from energy recovery operations are typically treated asenergy-related emissions in national energy balances and GHG emissions inventories(IPPC 2006). In cases where available data are inadequate—for example, whenfeedstock fuel data are available only on a gross (as opposed to a net) energy basis—all by-product combustion emissions are sometimes treated as NEU-CO2 emissions(Weiss et al. 2008; Patel et al. 2005).

New national emission inventory for navigation in Denmark

This article explains the new emission inventory for navigation in Denmark, covering national sea transport, fisheries and international sea transport. For national sea transport, the new Danish inventory distinguishes between regional ferries, local ferries and other national sea transport. Detailed traffic and technical data lie behind the fleet activity-based fuel consumption and emission calculations for regional ferries. For local ferries and other national sea transport, the new inventory is partly fleet activity based; fuel consumption estimates are calculated for single years, and full fuel consumption coverage is established in a time series by means of appropriate assumptions. For fisheries and international sea transport, the new inventory remains fuel based, using fuel sales data from the Danish Energy Authority (DEA). The new Danish inventory uses specific fuel consumption (sfc) and NO x emission factors as a function of engine type and production year. These factors, which are used directly for regional ferries and, for the remaining navigation categories, are derived by means of appropriate assumptions, serve as a major inventory improvement, necessary for making proper emission trend assessments. International sea transport is the most important fuel consumption and emission source for navigation, and the contributions are large even compared with the overall Danish totals. If the contributions from international sea transport were included in the Danish all-sector totals, the extra contributions in 2005 from fuel consumption (and CO 2), NO x and SO 2 would be 5%, 34% and 167%, respectively. The 1990–2005 changes in fuel consumption as well as NO x and SO 2 emissions for national sea transport (−45, −45, −81), fisheries (−18, 6, −18) and international sea transport (−14, 1, −14) reflect changes in fleet activity/fuel consumption and emission factors. The 2006–2020 emission forecasts demonstrate a need for stricter fuel quality and NO x emission standards for navigation, in order to gain emission improvements in line with those achieved for other mobile sources. The new fuel consumption estimates for national sea transport are regarded as much more accurate than the DEA fuel sales data used previously, and the recommendation for DEA is to replace their current fuel sales figures by the new estimates calculated in this project. Such updated fuel consumption time series for national sea transport will lead, in turn, to changes in the energy statistics for fisheries (gas oil) and industry (heavy fuel oil), so the national energy balance can remain unchanged. For international transport, fuel sales data as such are regarded as highly accurate for Denmark, since they are compiled from audited information from the Danish oil suppliers, and the inventory approach follows good practice for the United Nations Framework Convention of Climate Changes (UNFCCC) and United Nations Economic Commission for Europe (UNECE) convention, when fleet activity data are missing. However, in order to make inventory upgrades and to support Danish policymakers in bunker emissions allocation, fleet activity-based estimates calculated in a further project would be useful.

Analysis of Renewable Energy Situation in Jordan

Jordan, like most developing countries, has problems, constraints, and difficulties that mandate increasing renewable energy (RE) technology utilization. The most effective argument in favor of the adoption of RE technologies in Jordan is that its lack of conventional energy sources is complemented by abundant RE resources. Because RE technologies are not complex, require less operating and maintenance costs and are inherently more environmentally benign than conventional energy sources foster their consideration by energy policy makers as essential components of the national energy balance. The most prudent approach to address this strategic issue is to alleviate the problems, constrains, and difficulties associated with each of the above-mentioned influencing factors. This paper analyzes the current energy situation in Jordan, and discuses the importance of increasing the role of RE technologies in the energy mix. It also discusses some success stories in the RE technologies domain, analyzes the barriers affecting their development, and suggests future courses of action in order to attain their maximum utilization potential. It is believed that this paper will benefit energy policy makers in Jordan, as well as in other developing countries.

Constructing a greenhouse gas emissions inventory using energy balances: the case of South Africa for 1998

This paper discusses the procedures and results of constructing a greenhouse gas (GHG) emissions inventory for South Africa, using the official national energy balance for 1998. In doing so, the paper offers a snapshot of the South African energy supply and demand profile and encompassing greenhouse gas emissions profiles, disaggregated into 40 economic sectors, for the reference year. For convenience, energy supply and use are reported in both native units and terra joule (TJ), while emissions are expressed in carbon dioxide equivalents and reported in giga-gram (Gg). While carbon dioxide makes an overwhelming contribution to global anthropogenic GHG emissions, the inclusion of methane and nitrous oxide offers considerable richness to the analysis of climate change policies. Applying the energy balances, it was possible to compile a comprehensive emissions inventory using a consistent methodology across all sectors of the economy. The inventory allows the economic analyst to model various economic policies either with fuel as an input to production, or the consumption of fuel or the emissions generated during combustion, as a base of the analysis. The dominant role of coal as a source of energy, with a total primary energy supply (TPES) of 3.3 million TJ or 70 per cent of the total TPES, is clearly shown. Emissions from coal combustion (263 783 Gg of carbon dioxide equivalents or 74.7 per cent of total emissions) are henceforth the largest contributor to total emissions, estimated to be 352 932 Gg carbon dioxide equivalents.

Promotional policy and perspectives of usage renewable energy in Lithuania

The article outlines renewable energy (RE) sources according to the energy efficiency policy in Lithuania as well as practical experience of implementation of RE projects within the framework of the government policy to promote RES use due to the requirement of the European Union. The main goal of the country is to reduce the import of fossil fuel, to improve environment conditions and to reduce the climate change impact. Analysis of implemented RE projects and forecasts for the future projects are also presented. Most of the efforts in Lithuania were aimed at drafting the biomass (wood chips, wood waste, straw, biogas) and small hydro projects and their subsequent implementation. At present the total capacity of wood-chip-fuelled boilers reached above 251 MW. No serious obstacles can be seen for the extension of wood fuel use. At present, new demonstrational projects have been started covering geothermal energy, solar energy, biogas, biofuels for transport and other. In this time, the RE sources comprise 7.69% of national energy balance. Taking into account feasible resources of RE (it is more than 19.85 TWh/year) and the ongoing implementation of projects it is clear that the share of RE sources will constitute 12–13% of national energy balance in 2010 year. The main factor limiting further growth is high investment costs. The electricity production from local and RE sources in Lithuania is mainly based on hydro energy. At this time the wind energy is not used for this purpose. The electricity production from local and renewable energy sources is about 3.22% of the total consumption.

The state of renewable energy harnessing in Tanzania

This paper details the state of renewable energy development in Tanzania and biomass energy supply and consumption. It also highlights the various levels of renewable energy programmes in the country and the Government strategy to improve renewable energy production and utilization technologies. A number of problems hindering the development of renewable energy technologies have been identified and discussed. Biomass accounts for 92% of final energy consumption in Tanzania and will continue to dominate the national energy balance. For example, fuelwood and agricultural residues used to meet domestic energy needs account for 80% of the domestic energy requirements, while commercial energy such as kerosene, electricity and liquefied petroleum gas account for 1%. Total biomass resources for 1990 was 27 million tonnes of oil equivalent (TOE) from the natural forests. Other major industrial biomass energy sources include sawmill industry, sugarcane plantations, sugar industry by-products, cashew nut industry, coffee industry and sisal industry. The major biomass consumers include woodfuel for domestic use, tobacco production, brick making, tea drying and fish smoking. While there are efforts to develop other renewable sources of energy such as solar, wind and minihydros, there are also problems hindering their development. They include the lack of adequate data on the actual energy potential of these sources as well as the lack of local capability to design and manufacture energy related equipment and spare parts.

Raw Material as an Energy Source

This article discusses the role of chemical energy and exergy of raw material in industrial processes. The methods for calculation of chemical energies and exergies of some kinds of raw material are described. Their influence on consumption of conventional energy forms (fuel, heat, electricity) by the complete energy balance is shown. Consideration of the chemical energy and exergy in the national energy balances is suggested.

Regional and global exergy and energy efficiencies

We present estimates of global energy efficiency by applying second-law (exergy) analysis to regional and global energy balances. We use a uniform analysis of national and regional energy balances and aggregate these balances first for three main economic regions and subsequently into world totals. The procedure involves assessment of energy and exergy efficiencies at each step of energy conversion, from primary exergy to final and useful exergy. Ideally, the analysis should be extended to include actual delivered energy services; unfortunately, data are scarce and only rough estimates can be given for this last stage of energy conversion. The overall result is that the current global primary to useful exergy efficiency is about one-tenth of the theoretical maximum and the service efficiency is even lower.

Uncertainty in the National Energy Modeling System. II: Analysis of Results

This is the second of two papers on characterizing the uncertainty present in key elements of the U.S. Department of Energy's new National Energy Modeling System. The theory behind the assessment procedures developed was described in the first paper, and the current work presents the important numerical results and analyses of our experiments, all done as a collaborative effort between the Energy Information Administration, the Washington Consulting Group, and the School of Information Technology and Engineering of George Mason University. The method testing involved the three most important National Energy Modeling System submodel types, namely, linear optimization, econometric, and heuristic or balance equations. The results of using the uncertainty procedures on the Energy Information Administration's transportation sector demand and petroleum market models are provided here.

Future energy development in Tanzania: The energy costs of urbanization

This paper utilizes the detailed energy balance data developed as part of the Tanzania Urban Energy Project to examine future energy use in Tanzania. The energy costs of urbanization are shown to be quite substantial. National energy balances demonstrate that the urban areas make up a large share of the consumption of all fuels except woodfuel. As urbanization continues into the future, it will be accompanied by dramatic increases in the consumption of petroleum fuels, electricity and charcoal. For example, using base case or business as usual assumptions, over a planning period stretching from 1990 to 2010, every 1% increase in the level of urbanization can be expected to lead to a 12% increase in electricity consumption, a 14% increase in the consumption of all petroleum fuels and a 14% increase in the consumption of charcoal. Finally, the paper examines different energy policy options which are consistent with the stated national energy policy. After the examination of a set of ambitious policy efforts, a set of feasible policies are tested and shown to have a significant impact on the goals of improving efficiency, obtaining the desirable energy consumption profile and conserving indigenous woodfuel resources.

Woodfuel Use and Sustainable Development in Haiti

This paper examines energy use and environmental deterioration in Haiti. It applies linear programming to the national energy balance to analyze whether or not the substitution of kerosene or other petroleum fuels for charcoal is economically beneficial and whether it will result in a reduction of pressure for deforestation. It concludes that because of the inefficiencies in the production of charcoal, the substitution of kerosene for charcoal is an economically beneficial option. However, if stimulated through price incentives alone, it is unlikely to lead to an overall reduction in the quantity of wood used for fuel. Energy and environmental policy, therefore, must focus on interfuel substitution, improved efficiency and rural afforestation, in addition to getting the prices right.

Natural Gas and the Opening of the Single European Market

The share of natural gas in the national energy balance varies considerably from country to country in the EEC. The organization of production, imports, transport and distribution also differs greatly. Some countries have a state monopoly, while others allow a certain degree of competition among private or semi-private companies. Despite such differences, cooperation among EEC gas enterprises already exists. The Single European Act could upset the existing equilibrium if it were to lead to the adoption of the common carrier principle. While one can envision free transit of natural gas within the EEC and an abolition of the import monopoly where that exists, third party transport is likely to upset the economics of the present system, which is based on two principles: long-term contracts and the general acceptance of the net-back principle.

Análise de estabilidade no tempo das matrizes do balanço energético nacional (1976-1980)

This paper presents an analvsis cf time evolutiQn cf a matrix series. In the adopted methodology principal component analysis is used to characterize each matrix, and the time evolution analysis is obtained by comparing such components. An application of this methodo logy is presented in the analysis of time stability of the matrix series of National Energy Balance.

Energy resources in a third world microstate: St. Lucia household energy survey

Many countries have begun to examine their energy situations in order to develop a coherent national energy policy; such a policy requires much background data (e.g., domestic energy resources, imports, industrial and domestic consumption). One tool which can be used to provide such data is a national energy balance, a set of accounts which expresses the physical flows by which energy is produced, exchanged, transformed and consumed, all calculated in a common unit for a given time period. This paper reports the results of a household energy survey which is part of the attempt by one microstate, St. Lucia, to develop an energy balance study. Based on a national sample of 358 households, the paper calculates the average annual household energy consumption per household, with a focus on cooking fuels. The results indicate that the roles of firewood and charcoal have been greatly underestimated: 53% of total domestic energy use is based on local forest resources, indicating that the forest stock is seriously threatened, particularly as the price of ‘commercial’ fuels rises and results in substitution by so-called ‘non-commercial’ forest resources. Other conclusions are as follows: energy is often used with great inefficiency (e.g., 10% efficiency of wood fireplaces); there are great opportunities for important energy savings if efficiencies can be improved (e.g., improved charcoal production methods, reforestation with fast-growing species, improved stove design); cultural and institutional factors are important in changing energy technologies (e.g., traditional cooking patterns, role of government policy and education); increased national electricity production is the most expensive way to meet future energy needs; and a national energy policy is essential in the formulation of a national development policy.

The Brazilian ethanol program.

Brazilian needs for petroleum as a primary energy source grew from 13.2% in 1940 to 41.7% in 1977. This resulted in a much greater dependence on foreign sources and prompted the Government to initiate a detailed study of alternatives. The National Alcohol Program established in 1975 is just one of the options being examined. The National Energy Balance forecast shows that annual anhydrous alcohol consumption for automotive purposes should increase from 1.74 × 106 m3 to 4.7 × 106 m3 in the period from 1978 to 1987. This paper presents the main objectives of the National Alcohol Program in the context of the overall Energy Program, points out the problems connected with alcohol production and utilization, and reviews the serious problems related to its distribution to the consuming centers. Finally, the indirect benefits resulting from the implementation of the National Alcohol Program are shown, underlining the saving of foreign currency, the substantial increase in employment opportunities, the reduction in regional and individual income discrepancies, and the expansion of capital goods production, together with the improvement of national technology in the agricultural and industrial sectors.