Tallinn University of Technology

One of the pilot projects of the Smart City idea competition is Microgrids, which aims to to support the increased use of electricity generated locally from renewable energy sources.


The project intends to demonstrate how the implementation of closed distribution systems (CDS) inside electrical microgrids, formed by digital low voltage substations with energy storage systems, enables to reduce requirements for electricity supply through management of electricity consumption and decrease carbon-intensive electricity production by simplifying the uptake of renewable energy. Another aim of the project is to proof the concept of complementing standardized (or minimally customized) electricity distribution hardware with an overlaying software platform, which enables the implementation of software applications, to provide functionality within the microgrid. Interdisciplinary research is carried out in the scope of this project, which targets electric power quality in urban electricity distribution networks, energy markets and policies with a focus on CDSs and cyber-security in cyber-physical systems.

Four different institutions are engaged in this project: the Department of Power Engineering and Mechatronics and the Department of Software Science of TalTech along with the Municipalities of Lääne-Harju Parish and the City of Tartu. The content related project activities kicked off in March 2021 and during the first phase of the project, emphasis is placed on research, surveys and the preparation for tendering.

The Municipality partners contribute by collecting information from industry and commercial property owners to determine what they value in terms of power supply, which electric power system (EPS) services are attractive to them and which factors support and/or obstruct the uptake of renewable energy. For acquiring relevant information, surveys are carried out in an iterative manner, where the survey questionnaire is revised and the number of inquiries is increased with each iteration. Currently, over 35 inquiries have been sent with a response rate close to 35 %. Based on the initial analysis of responses, it can be determined that the topic of energy storage is actual among responders. The use-case of providing back-up power to avoid financial losses is well-known, while the awareness about other opportunities for adding value through energy storage and digital technology is low.

During the first months of activities, we have confirmed that interdisciplinary collaboration between cyber-security researchers and researchers of other disciplines has huge potential in achieving excellent outputs in respective applied research domains. In our initial interviews, we identified data privacy as a significant requirement in addition to the security-related requirements. Our ongoing literature review has confirmed our initial view about the research gaps so that detective and reactive security countermeasures (e.g., forensic investigations) have not been covered in the initial stages of development life cycles, especially via threat modelling, inducing important security problems in the running IT/OT systems or products. We have also identified additional significant research problems regarding the large-scale compromise of various smart grids, substations, or high-wattage IoT devices and the impact of this threat on energy transmission and distribution systems.

We have identified that municipal electricity distribution grids in Estonia use inflexible procedures for planning and equipment specification. While consumers are required to provide flexible and smart solutions, the potential of the distribution grid itself remains widely unused. By applying a holistic approach to urban public services, we can see the potential of existing municipal distribution grids in enabling to cover the requirements of a smart city, e.g. renewable energy communities and public charging for e-mobility. To enable increased usage of existing distribution infrastructure, we have conducted a literature research and classified existing load coordination methods. This research will be used to guide the development of a load coordination software application that will be demonstrated as a result of this project. Additionally, we have composed methodologies for planning suitable energy storage solutions and solving voltage problems in sparsely populated areas.

Our activities include the investigation of EU policies and regulations that influence the creation and management of CDSs and energy communities. Two types of energy communities are distinguished: Citizen Energy Communities and Renewable Energy Communities. This topic is mainly related to the

Clean energy for all Europeans package and 8 related directives, which state the obligation of each Member State to promote the development of CDSs and energy communities (with emphasis on Renewable Energy Communities). The general requirement is that Member States are to remove unjustified regulatory and administrative barriers, but each Member State retains the final say. Significant confining aspects to consider are that

  • Member States allowing Citizen Energy Communities to own and manage distribution networks need to ensure they are subject to the same regulatory framework as the current distribution system operator and
  • the Electricity Directive requires energy communities to contribute to network costs and remain financially responsible for imbalances caused in the system.

As a result of this project, two operational pilot sites are created with the aim to proof the concept of using a software platform and different applications to provide functionality inside microgrids. The pilot site at Lääne-Harju Parish enables to demonstrate the developed concept in an operational industry distribution grid to reduce requirements for electricity supply through the management of electricity consumption and increased use of electricity generated locally. The pilot site at the city of Tartu allows to demonstrate the developed concept in an operational urban distribution grid to increase the usage rate of electricity distribution grids to enable the provision of novel public services.

The project is led by Tarmo Korõtko from TalTech.

There are four Smart City pilot projects that have been chosen from Smart City Challenge 2020 and in 2021 two more ideas will be chosen. This pilot programme is managed by the Smart City Centre of Excellence and financed by the European Regional Development Fund and the Estonian Ministry of Research and Education.