The article gives an overview of various researches dealing with smart or intelligent street lighting systems, and what is meant with this term in different countries. Several available architectures of smart street lighting systems as well as those for future are described and discussed. Further some researches and developments of such systems in Riga Technical University are explained with the examples, also showing preliminary practical energy saving results of tests in real conditions of Riga city infrastructure. This is the first part of articles series about this research.

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.

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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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