Proportion and Quality Issues of Renewable Electrical Energy

Magistritöö Energiakasutuse õppekavalMagistritöös käsitletakse taastuvenergiaallikate osakaalu Eesti elektrienergia bilansis ning selle osakaalu mõjutegureid. Päikeseparkides läbiviidud katsemõõtmiste eesmärgiks on uurida päikeseparkide mõju elektrienergia kvaliteedile. Töös antakse ülevaade mõõtmiste tulemustest ning esitatakse sellekohane analüüs. Magistritöö eesmärgiks on uurida taastuvenergia osakaalu ning mõju elektrienergia kvaliteedile päikeseelektrijaamade näitel. Magistritöös kasutatakse erinevate andmebaaside statistilisi andmeid, tuginetakse erinevatele teadusartiklitele ning viiakse läbi tehnilised mõõtmised. 2019 aastaks oli taastuvenergia allikatest elektrivõrku genereeritud elektrienergia kogus võrreldes 2010 aastaga tõusnud 224%, samas on fossiilkütustest toodetud elektrienergia kogus vähenenud sama ajaperioodi jooksul 57% võrra. Magistritöö olulisus seisneb selles, et Eestis on vähe tehtud uurimustöid, mis analüüsiksid päikese- ja tuuleparkide mõju elektrienergia kvaliteedile.This master's thesis deals with the share of renewable energy sources in the Estonian electricity balance and the factors influencing it. The purpose of the experimental measurements performed in solar parks is to study their effect on the electric power quality. The thesis presents the results of the measurements, their analysis, as well as offers relevant conclusions. The aim of the master's thesis is to study the share of renewable energy and its impact on the power quality based on the example of solar power plants. This thesis uses statistical data from different databases, relies on various research articles and performs technical measurements. By 2019, the amount of electricity generated from renewable energy sources in the electricity grid had increased by 224% compared to 2010, while the amount of electricity produced from fossil fuels had decreased by 57% during the same period. The relevance of this master's thesis lies in the fact that little research has been conducted in Estonia to analyse the impact of solar and wind farms on the quality of electric power

Reducing of Energy Losses of Saw Dust Removal System

Bakalaureusetöö Tehnika ja tehnoloogia õppekavalKäesolevas töös analüüsiti puidutöötlemistehase aspiratsioonisüsteemi tehnoloogilist ja tehnilist olukorda ning võimalikke puudusi sellega seonduvalt. Uurimistöös käsitleti saepuru aspiratsioonisüsteemi energiakadude tekke põhjuseid ja energiakadude vähendamise võimalusi. Uurimustöö käigus teostati seadmete elektrivõrgu parameetrite mõõtmisi, s.h. aspiratsioonisüsteemi mootorite koormuste mõõtmisi, ventilatsioonitorustikus õhuhulkade ja õhukiiruste mõõtmisi. Saadud mõõtmistulemused näitasid, et tehase aspiratsioonisüsteemis on suured elektrilised kaod ja õhukaod. Elektriliste kadude põhjusteks on alakoormatud aspiratsioonisüsteemi mootorid samuti nende seadmete kasutamine ka töövälisel ajal. Õhukadude põhjusteks on mittevastav torustik, sulgsiibrite suured õhulekked. Antud mõõtmistulemuste järgi tehti kokkuvõttev alalüüs ja ettepanekud saepuru ärastussüteemis energiakadude vähendamiseks. Selleks tuleks seadmetele paigaldada kaasaegsed sulgsiibrid, vähendada magistraaltorustiku rõhutakistust koos selle dimensioneerimisega. Väljatõmbetorustiku erinevad liinid võib kokku ühendada, vähendades sellega ka mootorite alakoormust, mille tulemusena saavutatakse oluline kokkuhoid. Kuna antud töös ei käsitletud soojus- ja muid kadusid, ega tehnilisi lahendusi nende vähendamiseks, mida praegune tehniline olukord põhjustab, siis võib antud uurimistööd jätkata eelpoolmainitud teemade käsitlemisega.In this research work, the technological conformity, technical condition and the possible associated deficiencies of the aspiration system located in the wood processing plant were analysed. In this research work the causes behind the saw dust aspiration system’s energy losses and the possibilities for reducing those losses were covered. During the course of the research work the measurement of the electrical parameters of the equipment was performed, including load curve measurements, volumes of air in ventilation piping and air speed measurements. The obtained measurement results indicated that the plant’s aspiration system experiences significant electrical and air losses. Electrical losses are caused by the largely underloaded motors of the aspiration system as well as the use of that equipment outside of working hours. Air losses are caused by non-conforming piping and large air leaks from shut-off dampers. According to the obtained measurements, a summary analysis was prepared and proposals made for reducing the energy losses of the dust removal system. This would require the installation of modern shut-off dampers, and dimensioning and reducing the pressure resistance of the main pipelines. Various exhaust ventilation lines may be connected together, thereby reducing the underload on the motor, with the result being significant savings. Since the given work did not cover thermal and other losses, or the technical solutions for reducing them, which the current technical condition is causing, then the given research work could be continued by covering the above mentioned topics

Modelling the influence of Major Baltic Inflows on near-bottom conditions at the entrance of the Gulf of Finland

A coupled hydrodynamic-biogeochemical model was implemented in order to estimate the effects of Major Baltic Inflows on the near-bottom hydrophysical and biogeochemical conditions in the northern Baltic Proper and the western Gulf of Finland during the period 1991-2009. We compared results of a realistic reference run to the results of an experimental run where Major Baltic Inflows were suppressed. Further to the expected overall decrease in bottom salinity, this modelling experiment confirms that in the absence of strong saltwater inflows the deep areas of the Baltic Proper would become more anoxic, while in the shallower areas (western Gulf of Finland) near-bottom average conditions improve. Our experiment revealed that typical estuarine circulation results in the sporadic emergence of short-lasting events of near- bottom anoxia in the western Gulf of Finland due to transport of water masses from the Baltic Proper. Extrapolating our results beyond the modelled period, we speculate that the further deepening of the halocline in the Baltic Proper is likely to prevent inflows of anoxic water to the Gulf of Finland and in the longer term would lead to improvement in near-bottom conditions in the Baltic Proper. Our results reaffirm the importance of accurate representation of salinity dynamics in coupled Baltic Sea models serving as a basis for credible hindcast and future projection simulations of biogeochemical conditions.JRC.H.1-Water Resource

Modelling spatial dispersion of contaminants from shipping lanes in the Baltic Sea

Major sources of pollution from shipping to marine environments are antifouling paint residues and discharges of bilge, black, grey and ballast water and scrubber discharge water. The dispersion of copper, zinc, naphthalene, pyrene, and dibromochloromethane have been studied using the Ship Traffic Emission Assessment Model, the General Estuarine Transport Model, and the Eulerian tracer transport model in the Baltic Sea in 2012. Annual loads of the contaminants ranged from 10-2 tons for pyrene to 100 s of tons for copper. The dispersion of the contaminants is determined by the surface kinetic energy and vertical stratification at the location of the discharge. The elevated concentration of the contaminants at the surface persists for about two-days and the contaminants are dispersed over the spatial scale of 10-60 km. The Danish Sounds, the southwestern Baltic Sea and the Gulf of Finland are under the heaviest pressure of shipborne contaminants in the Baltic Sea

Modelling of discharges from baltic sea shipping

This paper describes the new developments of the Ship Traffic Emission Assessment Model (STEAM) which enable the modelling of pollutant discharges to water from ships. These include nutrients from black/grey water discharges as well as from food waste. Further, the modelling of contaminants in ballast, black, grey and scrubber water, bilge discharges, and stern tube oil leaks are also described as well as releases of contaminants from antifouling paints. Each of the discharges is regulated by different sections of the IMO MARPOL convention, and emission patterns of different pollution releases vary significantly. The discharge patterns and total amounts for the year 2012 in the Baltic Sea area are reported and open-loop SOx scrubbing effluent was found to be the second-largest pollutant stream by volume. The scrubber discharges have increased significantly in recent years, and their environmental impacts need to be investigated in detail

Validation of three-dimensional hydrodynamic models of the Gulf of Finland

A model-intercomparison study was conducted, the first of its kind for the Baltic Sea, whose aim was to systematically simulate the basic three-dimensional hydrographic properties of a realistic, complex basin. Simulations of the hydrographic features of the Gulf of Finland for the summer–autumn of 1996 by six three-dimensional hydrodynamic models were compared. Validation was undertaken using more than 300 vertical hydrographic profiles of salinity and temperature. The analysis of model performance, including averaging of the ensemble results, was undertaken with a view to assessing the potential suitability of the models in reproducing the physics of the Baltic Sea accurately enough to serve as a basis for accurate simulations of biogeochemistry once ecosystem models are incorporated. The performance of the models was generally satisfactory. Nevertheless, all the models had some difficulties in correctly simulating vertical profiles of temperature and salinity, and hence mixed layer dynamics, particularly in the eastern Gulf of Finland. Results emphasized the need for high resolution in both vertical and horizontal directions in order to resolve the complex dynamics and bathymetry of the Baltic Sea. Future work needs to consider the choice of mixing and advection schemes, moving to higher resolution, high-frequency forcing, and the accurate representation of river discharges and boundary conditions

The Copernicus Marine Environment Monitoring Service Ocean State Report

The Copernicus Marine Environment Monitoring Service (CMEMS) Ocean State Report (OSR) provides an annual report of the state of the global ocean and European regional seas for policy and decision-makers with the additional aim of increasing general public awareness about the status of, and changes in, the marine environment. The CMEMS OSR draws on expert analysis and provides a 3-D view (through reanalysis systems), a view from above (through remote-sensing data) and a direct view of the interior (through in situ measurements) of the global ocean and the European regional seas. The report is based on the unique CMEMS monitoring capabilities of the blue (hydrography, currents), white (sea ice) and green (e.g. Chlorophyll) marine environment. This first issue of the CMEMS OSR provides guidance on Essential Variables, large-scale changes and specific events related to the physical ocean state over the period 1993–2015. Principal findings of this first CMEMS OSR show a significant increase in global and regional sea levels, thermosteric expansion, ocean heat content, sea surface temperature and Antarctic sea ice extent and conversely a decrease in Arctic sea ice extent during the 1993–2015 period. During the year 2015 exceptionally strong large-scale changes were monitored such as, for example, a strong El Niño Southern Oscillation, a high frequency of extreme storms and sea level events in specific regions in addition to areas of high sea level and harmful algae blooms. At the same time, some areas in the Arctic Ocean experienced exceptionally low sea ice extent and temperatures below average were observed in the North Atlantic Ocean