Imre Drovtar

Large scale electric vehicle integration and its impact on the Estonian power system

This paper presents the main aspects of the study about large scale electric vehicle (EV) integration impacts in Estonia. The complex impact of EV charging and the resulting additional load demand on the Estonian power system is discussed. Two different charging principles are analysed - controlled and unmanaged. Standard and quick charging impacts are assessed together with the preheating strategies due to the climatic conditions. The aim of the paper is to model the impacts of EVs on the Estonian power system at sub regional level and to give an input for the Estonian TSO for its network development plans concerning e-mobility integration.

Electricity consumption analysis and power quality monitoring in commercial buildings

The results of the analysis of the electricity consumption and power quality indicators in two office buildings are presented. It comprises electricity consumption and power quality during work days and weekends. The consumption data analysed is from a one year period and the power quality analysis is based on a one week measuring period. The aim of this analysis is to determine the current situation in these buildings in order to study the possibilities and limitations to implement different energy efficiency measures. In addition to the energy efficiency point of view, the problem is also addressed together with the power quality aspects.

Overview — Pumped-hydro energy storage for balancing wind energy forecast errors

This paper analyses the increasing wind energy integration impacts on the Estonian power system, particularly wind energy production forecast errors. It proposes a solution to integrate wind parks with Estonian power grid, which is mainly based on large thermal power plants utilizing fossil fuels, together with a grid-scale energy storage system, particularly pumped-hydro energy storage, in order to balance the forecast errors in wind energy production utilization. Continuing increase of installed wind power capacity with its impacts on the grid is discussed. The last section describes a technical solution, simulated under real-time situation of the grid, which proves pumped-hydro energy storage as a suitable alternative.

Using demand side management in energy-intensive industries for providing balancing power - The Estonian case study

This paper represents the preliminary study results of industrial consumers who would be willing to provide demand response services for system balancing. Using aggregated load shifting in a wood industry over the whole Baltic power system for regulation is discussed. The paper covers the main aspects and assumptions used to assess the possible demand response outcomes for the transmission system operator in terms of regulation costs. The aim of the paper is to show that demand response can be deployed and consumers are willing to participate in providing demand response services for the transmission system operator, who should use this information as an input for developing the necessary market entity for balancing services.

Cost-effective optimization of load shifting in the industry by using intermediate storages

This paper presents the results of a study carried out with the help of industrial consumer who is willing to shift their electricity consumption in time. The aim of the study was to develop an optimization model for a specific load cycle in an industrial process e.g. a wood chipper. The paper covers the main aspects and assumptions used to assess the possible demand side management revenues for the industry. The model is used to optimize the wood chippers operation schedule according to the day-ahead spot market price information. The developed model and its results could be used by the industry as an input for optimizing its production cost for any industrial (sub) process under the open electricity market conditions.

Load control implementation in the energy intensive industry

This paper presents the principal solution for a real time load control application in the industry under the conditions of open electricity market. The aim of the study is to create the basic concept of a PLC controlled load optimization system for the group of energy intensive machines. The optimized load curve calculations for the specific machine or for the aggregated group of machines in the industry production process have been proposed using the optimization algorithm. The paper covers the main aspects and assumptions used to assess the possible demand side management revenues for the industry. The application is used to optimize the industry production cycles operation according to the day-ahead spot market price information. The developed application and its results could be used by the industry to optimize the whole production line electricity cost.

Wind park cost efficiency increase through direct cooperation with demand side response provider

Demand side response enables cost optimization for energy systems and consumers. By tradition, the target of the demand side response is to shift the loads from high price or peak-load periods to low price or low consumption periods. The economic effect is derived from reduced energy purchasing costs. This paper focuses on the possibility to provide demand side response for a wind park through direct cooperation by means of reduced production forecast errors. These errors are costly, as in open electricity market, overproduction is usually sold at a lower price and in underproduction it is required to purchase balancing energy from an electricity market. Forecasting errors always occur, as a forecast consists of wind speed predictions and does not take into account unexpected stops. Demand side response will reduce the imbalance between forecasted and actual production in wind parks. Direct cooperation between a response provider and a wind park is complex, as the forecast errors will define the need for the demand side response. For that reason, it is required to analyze wind park forecast errors in order to define the requirements for the demand side response capacity and an energy storage size. On the other hand, the solution proposed in this paper has benefits, as a demand side response provider does not need to participate in energy market. From that fact electricity market requirements are not applicable, as an example there is no need to have certain capacity available to participate in market.

Value Stream Mapping for Evaluation of Load Scheduling Possibilities in a District Heating Plant

Demand side response enables cost optimization for energy systems and industrial consumers. In many countries, it is not widely used because of implementation complexity. One of the solutions for applying demand side response is industrial process scheduling according to the energy market needs. From the energy system point of view, process scheduling implies load scheduling. The aim of this paper is to provide a solution for load scheduling by implementing value stream mapping, which is a straightforward enough for production management. Decision makers in the industry should have a clear understanding about positive effect from load scheduling and its effect to production outcome and process availability. Value stream mapping is a well-known process optimization tool from lean production philosophy. The aim of value stream mapping is to shorten the lead time of industrial processes and to reduce the intermediate stock amounts. By complementing value stream map with process energy intensity and energy stored in intermediate stocks, we can promote load scheduling possibilities. Our methodology provides a tool that is understandable and traceable for industry-minded decision makers. Finally, we present a real life test example for the new methodology, which is based on the production process of a district heating plant.

Comparison of renewable electricity generation options with household electrical load patterns

This paper analyzes output time-series of different small scale power generation systems such as wind and photovoltaic (PV) systems and their combinations, according to the wind and global irradiance data measured in the Tallinn-Harku Aerological Station (Estonia) and household load patterns. Renewable energy resources and energy production are reviewed and household loads and their need for stored energy reserves to cover periods without power generation are analyzed.

Impacts of large scale wind integration on the baltic region's thermal power plant economics and electricity market in 2025

This paper covers the analysis methods and results of the increasing wind integration impacts on the Baltic regions electricity market participants and power plant economics. The scope of the study is 2025 - when mayor decrease in generation capacities has occurred. The final part of the paper addresses the key findings that large scale wind integration might have on the economics of different generation technologies, with and without renewable electricity subsidies.