A heat storage system has been commissioned at the CHPP-2 generating facility of Latvenergo
Project 188.8.131.52/18/A/021 named “Creation of a heat storage system at CHPP-2, generating facility of Latvenergo AS” is implemented with co-funding of the European Union Cohesion Fund. The total project expenses amounted to EUR 9,045,041.85 million, with EUR 8,544,841.85 being eligible costs. The intended Cohesion Fund co-funding is 30% of eligible costs without exceeding EUR 2,563,452.55.
The heat storage system will ensure savings of primary energy sources (no less than 2,421 MWh/year), the reduction in CO2 (no less than 9,041 t/year), as well as will store at least 65,013 MWh of heat energy per year. The creation of the heat storage system will increase the security of heat supply of the Riga district heating system (DH) on the right bank. It will not only foster saving of energy sources and improvement of efficiency indicators, but also increase the use of CHPP-2 power-generating units in the cogeneration mode, creating additional conditions for a lower market price of electricity and heat in Riga and all over the country.
Latvenergo AS and the Central Finance and Contracting Agency (CFCA), based on Regulations of the Cabinet of Ministers No. 495 of 22 August 2017 “Implementing Regulations of the second round of selection of project applications for specific objective 4.3.1 “To promote energy efficiency and use of local RES in district heating” of the Operational Programme “Growth and Employment”” on 5 November 2018 has entered into agreement No.184.108.40.206/18/A/021 on the conditions and procedure of implementation of the project “Creation of a heat storage system at CHPP-2, generating facility of Latvenergo AS”. As a result of the procurement procedure, on 30 January 2019, an agreement was concluded with the UPB Joint Stock Company on the creation of a heat storage system at the CHPP-2 generating facility of Latvenergo AS”.
In 2019, it is planned to carry out a pre-feasibility study (including geological investigation and topographic surveys), development of the construction project, coordination of the construction project with the state authorities and start construction of the foundations for the heat storage tank.
Construction works are being performed in the project “Creation of a heat storage system at CHPP-2, generating facility of Latvenergo AS”. The foundations were laid in autumn 2019, and in January 2020 the construction of the roof of the heat storage tank started. Walls are being built in February.
The storage tank construction technology provides for lifting of the tank roof built on the construction site using jacks to build the tank wall belt under it. After the creation of each tank wall belt the structure will be lifted using jacks and built into the next tank wall belt until the designed storage tank height of 47.8 metres is reached. In parallel, the construction of foundations of the flyover for engineering utilities (pipelines, electric cables, communication cables) is ongoing.
New large-capacity heat storage projects with storage units with capacity up to 50,000 m³ have been installed and are planned to be installed in Europe in recent years. For example, about 12 heat storage tanks with capacity over 20 thousand m³ were installed in Germany in 2017.
In June 2020, the construction of main structures of the heat storage tank in the territory of CHPP-2 of Latvenergo AS was completed. Currently, construction works are still being performed in the project “Creation of a heat storage system at CHPP-2, generating facility of Latvenergo AS”. The heat storage tank has now reached the designed height of 47.8 meters. In parallel, the construction of foundations of the flyover for engineering utilities and for pumps is ongoing. A connection to the heating network has been constructed and shut-off valves on lines of power-generating units of CHPP-2 have been installed. The construction works will continue until the end of 2020. Adjustment and testing of the heat storage system was planned for the end of October 2020, but deliveries of equipment from European manufacturers intended for the construction of the storage system have been delayed due to the spread of COVID-19. Therefore, the implementation of the project “Creation of a heat storage system at CHPP-2, generating facility of Latvenergo AS” may be delayed even for several months.
A connection to the heating network has been constructed and shut-off valves on lines of power-generating units of CHPP-2 have been installed. In June 2020, the foundations of the flyover for engineering utilities and of the pumps were built, and the installation of technological pipelines was started. At the end of the summer, the main pumps of the system were installed and the storage tank was filled with a heat-transfer agent and the tank was hydrostatically tested. In September, the construction of process pipelines was completed and the construction of the thermal insulation of the heat storage tank was started. In the same month, it is planned to complete the pipeline connections to the main system pumps.
Adjustment and testing of the heat storage system was planned for December 2020 – beginning of 2021, because deliveries of equipment from European manufacturers intended for the construction of the heat storage system have been delayed due to the spread of COVID-19. The CHPP-2 heat storage system is planned to be commissioned in February 2020.
On 26 March 2021, the CHPP-2 heat storage system was commissioned after tuning and successful inspections.
The constructed heat storage system makes it possible to separate generation of heat and electricity, thus increasing flexibility of operations of CHPP-2 and the possibilities to better adapt operating modes in accordance with changes in electricity market conditions.