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Zeitschriftendaten
Format
Zeitschrift
eISSN
2255-8896
Erstveröffentlichung
18 Mar 2008
Erscheinungsweise
6 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 52 (2015): Heft 6 (December 2015)

Zeitschriftendaten
Format
Zeitschrift
eISSN
2255-8896
Erstveröffentlichung
18 Mar 2008
Erscheinungsweise
6 Hefte pro Jahr
Sprachen
Englisch

Suche

5 Artikel
Uneingeschränkter Zugang

Implementation of the Energy Efficiency Directive: Opportunities and Challenges

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 3 - 12

Zusammenfassung

Abstract

Discussions in Latvia are ongoing regarding the optimum solution to implementing Directive 2012/27/EU of the European Parliament and of the Council of 25 October 2012 on energy efficiency, amending Directives 2009/125/EC and 2010/30/EU and repealing Directives 2004/8/EC and 2006/32/EC (Directive 2012/27/EU). Without a doubt, increased energy efficiency contributes significantly to energy supply security, competitive performance, increased quality of life, reduced energy dependence and greenhouse gas (GHG) emissions. However, Directive 2012/27/EU should be implemented with careful planning, evaluating every aspect of the process.

This study analyses a scenario, where a significant fraction of target energy efficiency is achieved by obliging energy utilities to implement user-end energy efficiency measures. With implementation of this scheme towards energy end-use savings, user payments for energy should be reduced; on the other hand, these measures will require considerable investment. The energy efficiency obligation scheme stipulates that these investments must be paid by energy utilities; however, they will actually be covered by users, because the source of energy utilities’ income is user payments for energy. Thus, expenses on such measures will be included in energy prices and service tariffs.

The authors analyse the ways to achieve a balance between user gains from energy end-use savings and increased energy prices and tariffs as a result of obligations imposed upon energy utilities. Similarly, the suitability of the current regulatory regime for effective implementation of Directive 2012/27/EU is analysed in the energy supply sectors, where supply tariffs are regulated.

Schlüsselwörter

  • energy efficiency
  • energy efficiency obligation scheme
  • tariff adjustment
Uneingeschränkter Zugang

Justification of the Utility of Introducing Smart Meters in Latvia

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 13 - 21

Zusammenfassung

Abstract

Automatic data reading from smart meters is being developed in many parts of the world, including Latvia. The key drivers for that are developments of smart technologies and economic benefits for consumers. Deployment of smart meters could be launched in a massive scale.

Several pilot projects were implemented to verify the feasibility of smart meters for individual consumer groups. Preliminary calculations indicate that installation of smart meters for approximately 23 % of electricity consumers would be economically viable. Currently, the data for the last two years is available for an in-depth mathematical analysis. The continuous analysis of consumption data would be established, when more measurements from smart meters are available.

The extent of introduction of smart meters should be specified during this process in order to gain the maximum benefit for the whole society (consumers, grid companies, state authorities), because there are still many uncertain and variable factors. For example, it is necessary to consider statistical load variations by hour, dependence of electricity consumption on temperature fluctuations, consumer behaviour and demand response to market signals to reduce electricity consumption in the short and long term, consumer’s ambitions and capability to install home automation for regulation of electricity consumption.

To develop the demand response, it is necessary to analyse the whole array of additional factors, such as expected cost reduction of smart meters, possible extension of their functionality, further development of information exchange systems, as well as standard requirements and different political and regulatory decisions regarding the reduction of electricity consumption and energy efficiency.

Schlüsselwörter

  • smart grids
  • smart meter
  • energy efficiency
  • data transfer
Uneingeschränkter Zugang

The Evaluation of Feasibility of Thermal Energy Storage System at Riga TPP-2

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 22 - 37

Zusammenfassung

Abstract

The installation of thermal energy storage system (TES) provides the optimisation of energy source, energy security supply, power plant operation and energy production flexibility. The aim of the present research is to evaluate the feasibility of thermal energy system installation at Riga TPP–2. The six modes were investigated: four for non-heating periods and two for heating periods. Different research methods were used: data statistic processing, data analysis, analogy, forecasting, financial method and correlation and regression method. In the end, the best mode was chosen – the increase of cogeneration unit efficiency during the summer.

Schlüsselwörter

  • heat storage system (TES)
  • heat storage tank
  • modes
  • stratification
Uneingeschränkter Zugang

Efficient Use of Cogeneration and Fuel Diversification

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 38 - 48

Zusammenfassung

Abstract

Energy policy of the European Community is implemented by setting various goals in directives and developing support mechanisms to achieve them. However, very often these policies and legislation come into contradiction with each other, for example Directive 2009/28/EC on the promotion of the use of energy from renewable sources and Directive 2012/27/EU on energy efficiency, repealing Directive 2004/8/EC on the promotion of cogeneration based on a useful heat demand.

In this paper, the authors attempt to assess the potential conflicts between policy political objectives to increase the share of high-efficiency co-generation and renewable energy sources (RES), based on the example of Riga district heating system (DHS).

If a new heat source using biomass is built on the right bank of Riga DHS to increase the share of RES, the society could overpay for additional heat production capacities, such as a decrease in the loading of existing generating units, thereby contributing to an inefficient use of existing capacity.

As a result, the following negative consequences may arise: 1) a decrease in primary energy savings (PES) from high-efficiency cogeneration in Riga DHS, 2) an increase in greenhouse gas (GHG) emissions in the Baltic region, 3) the worsening security situation of electricity supply in the Latvian power system, 4) an increase in the electricity market price in the Lithuanian and Latvian price areas of Nord Pool power exchange.

Within the framework of the research, calculations of PES and GHG emission volumes have been performed for the existing situation and for the situation with heat source, using biomass. The effect of construction of biomass heat source on power capacity balances and Nord Pool electricity prices has been evaluated.

Schlüsselwörter

  • biomass boiler
  • combined heat and power plant
  • high-efficiency cogeneration
Uneingeschränkter Zugang

Mathematical Modeling of Dual Layer Shell Type Recuperation System for Biogas Dehumidification

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 49 - 60

Zusammenfassung

Abstract

The main aim of the current paper is to create a mathematical model for dual layer shell type recuperation system, which allows reducing the heat losses from the biomass digester and water amount in the biogas without any additional mechanical or chemical components. The idea of this system is to reduce the temperature of the outflowing gas by creating two-layered counter-flow heat exchanger around the walls of biogas digester, thus increasing a thermal resistance and the gas temperature, resulting in a condensation on a colder surface. Complex mathematical model, including surface condensation, is developed for this type of biogas dehumidifier and the parameter study is carried out for a wide range of parameters. The model is reduced to 1D case to make numerical calculations faster. It is shown that latent heat of condensation is very important for the total heat balance and the condensation rate is highly dependent on insulation between layers and outside temperature. Modelling results allow finding optimal geometrical parameters for the known gas flow and predicting the condensation rate for different system setups and seasons.

Schlüsselwörter

  • biogas
  • counter-flow heat exchanger
  • dehumidification
  • mathematical modelling
5 Artikel
Uneingeschränkter Zugang

Implementation of the Energy Efficiency Directive: Opportunities and Challenges

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 3 - 12

Zusammenfassung

Abstract

Discussions in Latvia are ongoing regarding the optimum solution to implementing Directive 2012/27/EU of the European Parliament and of the Council of 25 October 2012 on energy efficiency, amending Directives 2009/125/EC and 2010/30/EU and repealing Directives 2004/8/EC and 2006/32/EC (Directive 2012/27/EU). Without a doubt, increased energy efficiency contributes significantly to energy supply security, competitive performance, increased quality of life, reduced energy dependence and greenhouse gas (GHG) emissions. However, Directive 2012/27/EU should be implemented with careful planning, evaluating every aspect of the process.

This study analyses a scenario, where a significant fraction of target energy efficiency is achieved by obliging energy utilities to implement user-end energy efficiency measures. With implementation of this scheme towards energy end-use savings, user payments for energy should be reduced; on the other hand, these measures will require considerable investment. The energy efficiency obligation scheme stipulates that these investments must be paid by energy utilities; however, they will actually be covered by users, because the source of energy utilities’ income is user payments for energy. Thus, expenses on such measures will be included in energy prices and service tariffs.

The authors analyse the ways to achieve a balance between user gains from energy end-use savings and increased energy prices and tariffs as a result of obligations imposed upon energy utilities. Similarly, the suitability of the current regulatory regime for effective implementation of Directive 2012/27/EU is analysed in the energy supply sectors, where supply tariffs are regulated.

Schlüsselwörter

  • energy efficiency
  • energy efficiency obligation scheme
  • tariff adjustment
Uneingeschränkter Zugang

Justification of the Utility of Introducing Smart Meters in Latvia

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 13 - 21

Zusammenfassung

Abstract

Automatic data reading from smart meters is being developed in many parts of the world, including Latvia. The key drivers for that are developments of smart technologies and economic benefits for consumers. Deployment of smart meters could be launched in a massive scale.

Several pilot projects were implemented to verify the feasibility of smart meters for individual consumer groups. Preliminary calculations indicate that installation of smart meters for approximately 23 % of electricity consumers would be economically viable. Currently, the data for the last two years is available for an in-depth mathematical analysis. The continuous analysis of consumption data would be established, when more measurements from smart meters are available.

The extent of introduction of smart meters should be specified during this process in order to gain the maximum benefit for the whole society (consumers, grid companies, state authorities), because there are still many uncertain and variable factors. For example, it is necessary to consider statistical load variations by hour, dependence of electricity consumption on temperature fluctuations, consumer behaviour and demand response to market signals to reduce electricity consumption in the short and long term, consumer’s ambitions and capability to install home automation for regulation of electricity consumption.

To develop the demand response, it is necessary to analyse the whole array of additional factors, such as expected cost reduction of smart meters, possible extension of their functionality, further development of information exchange systems, as well as standard requirements and different political and regulatory decisions regarding the reduction of electricity consumption and energy efficiency.

Schlüsselwörter

  • smart grids
  • smart meter
  • energy efficiency
  • data transfer
Uneingeschränkter Zugang

The Evaluation of Feasibility of Thermal Energy Storage System at Riga TPP-2

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 22 - 37

Zusammenfassung

Abstract

The installation of thermal energy storage system (TES) provides the optimisation of energy source, energy security supply, power plant operation and energy production flexibility. The aim of the present research is to evaluate the feasibility of thermal energy system installation at Riga TPP–2. The six modes were investigated: four for non-heating periods and two for heating periods. Different research methods were used: data statistic processing, data analysis, analogy, forecasting, financial method and correlation and regression method. In the end, the best mode was chosen – the increase of cogeneration unit efficiency during the summer.

Schlüsselwörter

  • heat storage system (TES)
  • heat storage tank
  • modes
  • stratification
Uneingeschränkter Zugang

Efficient Use of Cogeneration and Fuel Diversification

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 38 - 48

Zusammenfassung

Abstract

Energy policy of the European Community is implemented by setting various goals in directives and developing support mechanisms to achieve them. However, very often these policies and legislation come into contradiction with each other, for example Directive 2009/28/EC on the promotion of the use of energy from renewable sources and Directive 2012/27/EU on energy efficiency, repealing Directive 2004/8/EC on the promotion of cogeneration based on a useful heat demand.

In this paper, the authors attempt to assess the potential conflicts between policy political objectives to increase the share of high-efficiency co-generation and renewable energy sources (RES), based on the example of Riga district heating system (DHS).

If a new heat source using biomass is built on the right bank of Riga DHS to increase the share of RES, the society could overpay for additional heat production capacities, such as a decrease in the loading of existing generating units, thereby contributing to an inefficient use of existing capacity.

As a result, the following negative consequences may arise: 1) a decrease in primary energy savings (PES) from high-efficiency cogeneration in Riga DHS, 2) an increase in greenhouse gas (GHG) emissions in the Baltic region, 3) the worsening security situation of electricity supply in the Latvian power system, 4) an increase in the electricity market price in the Lithuanian and Latvian price areas of Nord Pool power exchange.

Within the framework of the research, calculations of PES and GHG emission volumes have been performed for the existing situation and for the situation with heat source, using biomass. The effect of construction of biomass heat source on power capacity balances and Nord Pool electricity prices has been evaluated.

Schlüsselwörter

  • biomass boiler
  • combined heat and power plant
  • high-efficiency cogeneration
Uneingeschränkter Zugang

Mathematical Modeling of Dual Layer Shell Type Recuperation System for Biogas Dehumidification

Online veröffentlicht: 22 Jan 2016
Seitenbereich: 49 - 60

Zusammenfassung

Abstract

The main aim of the current paper is to create a mathematical model for dual layer shell type recuperation system, which allows reducing the heat losses from the biomass digester and water amount in the biogas without any additional mechanical or chemical components. The idea of this system is to reduce the temperature of the outflowing gas by creating two-layered counter-flow heat exchanger around the walls of biogas digester, thus increasing a thermal resistance and the gas temperature, resulting in a condensation on a colder surface. Complex mathematical model, including surface condensation, is developed for this type of biogas dehumidifier and the parameter study is carried out for a wide range of parameters. The model is reduced to 1D case to make numerical calculations faster. It is shown that latent heat of condensation is very important for the total heat balance and the condensation rate is highly dependent on insulation between layers and outside temperature. Modelling results allow finding optimal geometrical parameters for the known gas flow and predicting the condensation rate for different system setups and seasons.

Schlüsselwörter

  • biogas
  • counter-flow heat exchanger
  • dehumidification
  • mathematical modelling

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