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  • Author: Dagnija Blumberga x
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Financial support is needed in order to implement renewable resources in countries energy sector in the shortest time period. Among the most important supports for European Union Member states are feed-in tariff and feed-in tariff premiums. This research analyses one country’s experience in applying subsidies of the electricity tariff that has caused public protests after 20 years. There are many reasons for this which are analysed in the paper. One of the most important reasons of high subsidies of energy tariffs – coincident mandatory procurement implementation of application of fossil fuel (imported natural gas) for cogeneration units, which has to be classified as external mover (initiator) factor. Energy sector’s potential development scenarios with or without support for renewable energy resources are being analysed in the paper.

Use of Benchmark Methodology in Environmental Impact Assessment

Every industrial activity and procedure influences the environment and climate change. This impact has to be assessed and therefore the procedure of Environmental Impact Assessment (EIA) including the application of a benchmark methodology has been developed. The developed benchmark methodology can be used in the initial assessment as a screening method. The article surveys the developed benchmark methodology for impact assessment of the projects providing extraction of dolomite in the deposits of mineral resources. The benchmark methodology developed makes it possible to assess the impacts caused by the provided activity by objective considerations, to conduct comparison of different projects and evaluate whether the provided activity corresponds to the principles of sustainable development.

Teaching Applied Geophysics at RTU: the Basics for a Fast, Green, Inexpensive Subground Investigation Method

Geophysical methods are applied to determine a spatial model of the underground, to locate fault zones, to investigate the regional ground-water system, or to derive lithological parameters. In other words, applied geophysics provides the distribution of physical parameters of the subsurface through surveys at the earth's surface without destroying soil formations. In Latvia there are few expert companies of geophysics surveys.

Thus, it is important that environmental experts have knowledge in this, and that Latvia, as a country, has access to international expertise.

During the study introduced hereto we compared the geophysics course in the Riga Technical University (RTU) with similar courses in eight European universities and one Latvian university, gathering information through websites and/or personal contacts. We collected information about the duration of the courses, learning objectives, topics, teaching methods, credit points etc. As a result, proposals on how to improve the course in RTU were elaborated.

Modelling of the District Heating System's Operation

The development of a district heating systems calculation model means improvement in the energy efficiency of a district heating system, which makes it possible to reduce the heat losses, thus positively affecting the tariffs on thermal energy.

In this paper, a universal approach is considered, based on which the optimal flow and temperature conditions in a district heating system network could be calculated. The optimality is determined by the least operational costs. The developed calculation model has been tested on the Ludza district heating system based on the technical parameters of this system.


When the renewable energy is used, the challenge is match the supply of intermittent energy with the demand for energy therefore the energy storage solutions should be used. This paper is dedicated to hydrogen accumulation from wind sources. The case study investigates the conceptual system that uses intermitted renewable energy resources to produce hydrogen (power-to-gas concept) and fuel (power-to-liquid concept). For this specific case study hydrogen is produced from surplus electricity generated by wind power plant trough electrolysis process and fuel is obtained by upgrading biogas to biomethane using hydrogen. System dynamic model is created for this conceptual system. The developed system dynamics model has been used to simulate 2 different scenarios. The results show that in both scenarios the point at which the all electricity needs of Latvia are covered is obtained. Moreover, the methodology of system dynamics used in this paper is white-box model that allows to apply the developed model to other case studies and/or to modify model based on the newest data. The developed model can be used for both scientific research and policy makers to better understand the dynamic relation within the system and the response of system to changes in both internal and external factors.


Modern urban planning in the world is nowadays facing severe problems due to the fast increase of the population and migration from villages to cities, which led countries to implementation of strategy of fast, modern urban planning to meet the needs of the population. Since the 1980s, in a context marked by increasing development in energy costs and by rising attention to the problem of global warming, countries have gradually mobilized to control their energy better and reduce the environmental footprint. However, even if there are some great successes, the deployment of renewable energies is still not well developed in developing countries such as Algeria that mainly uses fossil fuels. Considering the huge potential and good climatic conditions, developing countries should take on renewable energies for their future development. This paper aims to understand the impact of modern urban strategy on the application of solar urban planning. This study will clarify the critical role of solar electricity integration used in determining the urban solar potential in four studied regions located on three different continents: Africa, Europe and North America, in the cities of Ibenbadis (Constantine, Algeria), Saint-Hugues (Quebec, Canada), Saint-Malo (France) and Ambolobozobe (Madagascar). The results obtained will allow a comparison of the calculated solar energy potential of three urban sites, the benefits of reducing carbon dioxide as well as a comparison of solar energy costs on three continents.

Biogas from Marine Macroalgae: a New Environmental Technology — Life Cycle Inventory for a Further LCA

The main goal of this paper is to analyze the innovative process of production of biogas (via fermentation processes) using marine macroalgae as feedstock in a pilot project plant in Augusta (Sicily, Italy). Algae, during their growth, have the capacity to assimilate nutrients and thus subsequent harvesting of the algal biomass recovers the nutrients from biowaste sources giving the possibility to transform negative environmental externalities in positive mainly in terms of eutrophication and climate change impact categories.

The paper presents a novel environmental technology for the production of biogas and 2nd generation biofuel (liquid biomethane) after an upgrading process through the use of a cryogenic technology. The paper would also like to make the first attempt at understanding the possibility to implement this innovative technology in the Latvian context.

The first calculations and assumptions for the Life Cycle Inventory for a further Life Cycle Assessment are presented.

Description of Latvian Metal Production and Processing Enterprises' Air Emissions

The metal production and processing sector in Latvia has acquired a stable position in the national economy. Smelting of ferrous and nonferrous metals, production of metalware, galvanisation, etc. are developed in Latvia. The metal production and processing sector has an impact on air quality due to polluting substances which are released in the air from metal treatment processes. Therefore it is necessary to determine the total volume of emissions produced by the metal production and processing sector in Latvia. This article deals with the air polluting emissions of the Latvian metal production and processing industry, and sets the optimum sector emission volumes using the emissions benchmark methodology.

Climate Technology in a Wood Chips Boiler House

One of the innovative solutions of climate technologies is a pilot project relating to the condenser of fuel combustion products which is installed at a chips-fuelled boiler house in the Ludza city. A commercial experiment with the use of a gas condenser has been run at a boiler-house. An empirical model has been obtained, that describes the relation between the specific greenhouse gas (GHG) emissions reduction and the temperature difference of irrigation liquid & condensate mixture.