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  • Author: M. Kunickis x
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Justification of the Utility of Introducing Smart Meters in Latvia


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.

Open access
Efficient Use of Cogeneration and Fuel Diversification


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.

Open access
Consistency Analysis and Data Consultation of Gas System of Gas-Electricity Network of Latvia


In the present research, the main critical points of gas transmission and storage system of Latvia have been determined to ensure secure and reliable gas supply among the Baltic States to fulfil the core objectives of the EU energy policies.

Technical data of critical points of the gas transmission and storage system of Latvia have been collected and analysed with the SWOT method and solutions have been provided to increase the reliability of the regional natural gas system.

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Risk Treatment and System Recovery Analysis of Gas System of Gas and Electricity Network of Latvia


The Latvian natural gas system is interconnected with transmission networks located in Lithuania, Estonia and Russia. Natural gas commercial metering is provided by GMS “Karksi” (Estonia) and by GMS “Kiemenai” (Lithuania). Natural gas is supplied to all larger urban areas in Latvia. Natural gas is supplied to Latvia along the Latvian–Russian pipeline only during the warm period of the year (April–September), and it is accumulated in the underground gas storage facility in Incukalns. During winter, gas from the underground facility is delivered to Latvian customers, as well as transmitted to Estonia and back to Russia. There is also a connection to Lithuania. Out of the gas supply disruption risks that are assessed at different levels, the essential one with a trans-border impact potential consists in the insufficient technical capacity of Incukalns UGS. Given the current technical possibilities, IUGS cannot pass the gas volume required for the Baltic States to compensate the gas supply deficit. The paper performs system recovery analysis after selected critical events. The paper provides a report describing the steps to be followed in order to restore the gas transmission system to normal operation after selected critical events. A very significant region of the power system of Latvia is the central part of Latvia and Riga region, where both of Riga CHPs, as well as Riga HPP, is located. The restoration time of the gas system of Latvia depends on the gravity of the situation and damage in the gas system and may range from several hours to several days.

Open access
The effect of preliminary chilling of broccoli transplants on some antioxidative parameters


The aim of this study was to introduce older transplants of broccoli into field conditions to shorten their growing period and to obtain a crop with a high nutritive value. The additional storage of relatively old (four- and eightweek- old) transplants in a cold chamber before planting in the field shortens the growing period; however, it can influence the chemical composition of the leaves and heads. According to earlier research, the preliminary chilling of transplants affected the high yielding of broccoli; a determination of the quality of plants, including select health-promoting properties, was necessary for their full characteristics.

In the present work, the four- and eight-week-old broccoli transplants were kept at 2°C either for one or two weeks before planting in the field. Catalase (CAT) and peroxidase (POD) activity as well and the accumulation of phenolic compounds were determined in the leaves of the transplants before and after chilling. The same parameters were detected in the leaves and heads of broccoli at harvest time. The effect of low temperature treatment on CAT activity was observed only at the stage of transplants; however, the increased activity of POD stimulated by chilling was maintained during the growing period until the harvest. The reaction of the plants to low temperatures can be connected with their mechanism against stress conditions and seems to vary in the case of those antioxidative enzymes. The effect of chilling on the accumulation of phenolics (total, cinnamic acid derivatives, flavonols) was noted only in transplants and was not evident during the harvest.

The differences observed between the individual seasons of the experiment, both in enzyme activity and synthesis of phenolics, were most likely caused by the differing climatic conditions

Open access