Tallinn University of Technology

Research Group of Sustainable Energy and Fuels

Head of the research group: Tenured Associate Professor Alar Konist PhD, alar.konist@taltech.ee
Members: Tõnu Pihu PhD, Dmitri Nešumajev PhD
PhD students: Alejandro Lyons Ceron, Liisa-Maria Kaljusmaa, Mais Baqain, Mari Sinisalu, Mari-Liis Ummik, 
Keywords – fuels, combustion, pyrolysis, gasification, ash, activation energies, CO2 emissions, CCS and CCU (inc. Oxyfuel)

Alari uurimisrühm

Topics and Competences
Moving toward zero carbon emissions is an ultimate goal for energy technology. The group intends to tackle the problem by studying the possibilities of oxy-fuel co-combustion of oil shale (OS) and biomass in circulating fluidized bed (CFB) boiler. Further, utilization of the remaining Ca-rich ash as a bed material for binding CO₂ (also SOx and NOx) in fluidized bed combustion of biomass for achieving negative carbon emissions in biomass combustion will be studied. Lab-scale up to semi- industrial scale experiments will be carried out to investigate the combustion process parameters to achieve this.

Also, the group deals with better characterization of the fly ash, in order to enable more effective use of the ash that is formed under oxyfuel combustion conditions. The "organic and in-organic" (carbon) portion of the ash is the key to success in many new utilization schemes.

A broad-based scientific investigation of the form, sorptive properties and behaviour of the in/organic material in ash samples is carried out in order to help identify new commercial opportunities.

The accredited laboratory group provides accredited sample analyses for various customers.

Results: Based on the results of the research group, oil shale ashes are considered as non-hazardous waste materials since 01.01.2020.

PSG266 - Effects of activation conditions on preparation of porous carbon from oil shale (2019-2022)
RITA1/02-20 - Climate change mitigation with CCS and CCU technologies (2019 – 2021)
LEP17084 - Fundamental Research studies on thermochemical conversion of local biomass in Utilitas Tallinn powerplant (2017 – 2020)
LEP19011 Fundamental Research studies on Oil Shale Technologies at Enefit Energiatootmise AS (2019)
LMIN18074 - Potential hazardousness of Estonian oil shale ashes (2018 – 2019)

Konist, A.; Jarvik, O.; Pikkor, H.; Neshumayev, D.; Pihu, T. (2019). Utilization of pyrolytic wastewater in oil shale fired CFBC boiler. Journal of Cleaner Production, 234, 487−493.10.1016/j.jclepro.2019.06.213.
Maaten, B.; Konist, A.; Siirde, A. (2019). High-speed thermogravimetric analysis of the combustion of wood and Ca-rich fuel. Journal of Thermal Analysis and Calorimetry.10.1007/s10973-019-08785-6.
Neshumayev, D.; Pihu, T.; Siirde, A.; Jarvik, O.; Konist, A. (2019). Solid heat carrier oil shale retorting technology with integrated CFB technology. Oil Shale, 36 (2), 99−113.10.3176/oil.2019.2S.02.

Research Group of Smart District Heating Systems and Integrated Assessment Analysis of Greenhouse Gases Emissions

Head of the research group: Tenured Associate Professor Anna Volkova PhD, Phone +372 620 3905, anna.volkova@taltech.ee
Members: Andrei Dedov PhD, Eduard Latõšov PhD, Igor Krupenski PhD, Vladislav Mašatin PhD, Aleksandr Hlebnikov PhD, Inge Roos PhD, Sreenath Sukumaran PhD

PhD students: Kertu Lepiksaar


Group deals with developing new technical solutions for the transition of district heating (DH) systems towards an intelligent, highly efficient and regenerative energy supply concept and with integrated assessment analysis of greenhouse gases emissions. The main research topics are related to transition and improvement measures for existing and technical solutions for planned district heating systems.

Group recent research activities are connected with the analysis of:

  • Existing large-scale DH system transition towards 4th generation DH
  • Thermal energy storage coupling with biomass CHP
  • Low temperature DH networks
  • Large heat pumps integration into DH systems
  • Power plant operation strategy integrating accumulator tank
  • Development plans for DH regions
  • GIS based optimisation of district heating networks
  • Sustainable district heating promotion mobile app NutiSoojus
  • Parallel consumption impact on district heating
  • Optimisation of district heating networks
  • Calculation of primary energy factors for district heating and cooling
  • Planning of district heating regions
  • Return temperature reduction impact on high temperature district heating system
  • Low temperature district heating network's (LTDHN) heat supply option from the return line of a well-established high temperature district heating system

Recent most important research projects:

  • Heat pump potential in Baltic States (2020 – 2021), Nordic Energy Research

    The focus area for the project is to examine heat pump potential and socio-economic costs in the Baltic States. Key tasks will be to assess the potential of high temperature heat sources for large heat pumps and electric boilers, the potential for and cost-efficiency of large sea water heat pumps, potential for heat pumps in the end-use sectors, as well as potential and socio-economic costs of individual heat pumps

  • Techno-economic performance and feasibility study of the 5GDHC technology using agent based modelling and GIS (2020 – 2022), Nordic Energy Research

    In the frame of this project, a simulation platform will be developed using agent-based modelling and GIS to evaluate the technical and economic performance of the 5GDHC technology and study possible applications of the 5GDHC in the Baltic and Nordic regions.

  • A comprehensive toolbox for integrating​ low-temperature sub-networks in existing district heating networks (2020 – 2022), International Energy Agency

    The main objective of the project is to develop generalizable solutions for the implementation and large-scale replication of energy cascading through sub-LTDHNs and disseminate the findings to national district heating associations and DH suppliers.


The untapped potential of natural and industrial heat sources to provide sustainable district heating (taltech.ee)

Таллиннцы получат в январе огромные счета за отопление: цены вырастут на 56% - Delfi RUS

Scientific papers published or accepted in 2018-2020

Volkova, A.; Krupenski, I.; Ledvanov, A.; Hlebnikov, A.; Lepiksaar, K.; Latõšov, E.; Mašatin, V. (2020). Energy cascade connection of a low-temperature district heating network to the return line of a high-temperature district heating network. Energy, 198, #117304. DOI: https://doi.org/10.1016/j.energy.2020.117304

Lepiksaar, K.; Volkova, A.; Rušeljuk, P.; Siirde, A. (2020). The effect of the District Heating Return Temperature Reduction on Flue Gas Condenser Efficiency. Environmental and Climate Technologies , 24, 3, 23−38. DOI: https://doi.org/10.2478/rtuect-2020-0083

Rušeljuk, P.; Volkova, A.; Lukić, N.; Lepiksaar, K.; Nikolić, N.; Nešović, A.; Siirde, A. (2020). Factors Affecting the Improvement of District Heating. Case Studies of Estonia and Serbia. Environmental and Climate Technologies , 24, 3, 521−533. DOI: https://doi.org/10.2478/rtuect-2020-0121

Volkova A., Latõšov E., Siirde A. (2020) Heat storage combined with biomass CHP under the national support policy. A case study of Estonia, . Environmental and Climate Technologies, Vol. 24

Volkova, A.; Latõšov E.; Lepiksaar K.; Siirde A. (2020). Planning of district heating regions in Estonia. International Journal of Sustainable Energy Planning and Management, Vol.25, 2020

Latõšov, E.; Siirde, A.; Volkova, A.; Thaldfeldt, M.; Kurnitski, J. (2019). The impact of parallel energy consumption on the district heating networks. Environmental and Climate Technologies, 23, 1−13.10.2478/rtuect-2019-0001.

Volkova, A.; Latõšov, E.; Mašatin, V.v; Siirde, A. (2019). Development of a user-friendly mobile app for the national level promotion of the 4th generation district heating. International Journal of Sustainable Energy Planning and Management, 19, 21−35.10.5278/ijsepm.2019.20.3 .

Pieper, H.; Mašatin, V.; Volkova, A.; Ommen, T.; Elmegaard, B.; Markussen, V. B. (2019). Modelling framework for integration of large-scale heat pumps in district heating using low-temperature heat source. International Journal of Sustainable Energy Planning and Management, 67−86.10.5278/ijsepm.2019.20.6 .

Krupenski, I.; Volkova, A.; Pieper, H.; Ledvanov, A.; Latõšov, E.; Siirde, A. (2019). Small low-temperature district heating network development prospects. Energy, 714−722.10.1016/j.energy.2019.04.083.

Reino, A.; Latõsov, E.  Impact of Primary Energy Factors to Achieving Building Energy Performance Targets in Estonia. 7. European Conference on Renewable Energy Systems ECRES 2019 PROCEEDINGS  10.-12.juuni 2019, Madrid, Hispaania. Ed. E. Kurt, J. Manuel Lopez Guede, F. Petrakopoulou Robinson. Erciyes University , 670−679.

Lukic, N.; Nešović, A.; Nikolić, N.; Siirde, A.; Volkova, A.; Latosov, E. (2019). Energy performance of the Serbian and Estonian family house with a selective absorption facade. IOP Conference Series: Materials Science and Engineering, 659 (1), 012047.10.1088/1757-899X/659/1/012047.

Volkova, A.; Siirde, A.; Mašatin, V. (2018). Methodology for evaluating the transition process dynamics towards 4th generation district heating systems. Energy, 150, 253−261.10.1016/j.energy.2018.02.123.

Thalfeldt, M.; Kurnitski, J.; Latõšov, E. (2018). Exhaust air heat pump connection schemes and balanced heat recovery ventilation effect on district heat energy use and return temperature. Applied Thermal Engineering, 128, 402−414.10.1016/j.applthermaleng.2017.09.033.

Volkova, A.; Latõšov, E.; Andrijaškin, M.; Siirde, A. (2018). Feasibility of Thermal Energy Storage Integration into Biomass CHP-Based District Heating System. Chemical Engineering Transactions, 70, 499−504.10.3303/CET1870084.

Latõšov, E.; Maaten, B.; Siirde, A.; Konist, A. (2018). The influence of O2 and CO2 on the possible corrosion on steel transmission lines of natural gas. In: S. Valtere (_EditorsAbbr). Energy Procedia (63−70). Elsevier.10.1016/j.egypro.2018.07.034.

Chicherin, S.; Volkova, A.; Latõšov, E. (2018). GIS-based optimisation for district heating network planning. Energy Procedia, 149, 635−641.10.1016/j.egypro.2018.08.228.

Latõšov, E.; Volkova, A.; Hlebnikov, A.; Siirde, A. (2018). Technical improvement potential of large district heating network: application to the Case of Tallinn, Estonia. Energy Procedia, 149, 337−344.10.1016/j.egypro.2018.08.197.

Laboratory of Fuel and Air Emission Analysis

Head of the Labortory: Tenured Associate Professor Oliver Järvik PhD, Phone +372 620 3909, oliver.jarvik@taltech.ee
Members: Inna Kamenev PhD, Jelena Veressinina, Sven Kamenev, Liisi Blank, Iige Brempel, Tiina Ailt, Erki Leht

PhD students: Kati Roosalu