Latvenergo AS owns two large combined heat and power plants – Riga CHPP-1 and Riga CHPP-2.
The upgraded Riga CHPPs owned by Latvenergo Group are operated mostly in the highly efficient cogeneration mode to cover the demanded thermal volume. Consequently, generation of electricity at the combined heat and power plant depends largely on thermal energy consumption, which in turn depends on the climate conditions and duration of the heating season, as well as on the electricity market situation.
Riga CHPPs guarantee significant electricity base-load capacity that can almost fully cover the entire Latvian electricity consumption in circumstances where due to some factors electricity import from foreign countries is limited. In such cases, the plants can operate as stable base-load capacity facilities that will promptly substitute shortage of cross-border supply.
The Riga CHPPs use natural gas as the primary fuel, which is environmentally the friendliest type of fossil fuel available for power generation. In order to ensure the reliability of thermal energy supply in emergency situations (emergency cut-offs), Riga CHPPs store back-up fuel reserves of diesel.
The amount of electricity generated by the Riga CHPPs in 2017 was 1,411 GWh, a 36% decrease compared to the previous year. This was mainly due to the untypically high electricity output at the Daugava HPPs. The Riga CHPPs operate efficiently and flexibly, adapting their operational modes to the electricity market’s conditions. The amount of electricity generated by the Riga CHPPs in 2017 was 25% of Latvenergo Group’s total electricity output.
The amount of thermal energy generated by the Riga CHPPs in 2017 was 2,349 GWh or 3% less compared to the previous year. Thermal energy generated by the Riga CHPPs is supplied to Rīgas siltums AS at regulated tariffs.
The Riga CHPP-1 was built from 1954 to 1958, and it was completely reconstructed in 2005. The plant employs two gas turbines, one steam turbine and three water heating boilers. The electric capacity installed in CHPP-1 is 144 MW, while the thermal capacity is 493 MW.
The basis of the plant’s operation is combined generation of thermal energy and electricity. The generated electricity is transmitted from CHPP-1 to Latvijas elektriskie tīkli AS, while the generated thermal energy is sold by Rīgas siltums AS, which ensures central heating and hot water supply for the city of Riga.
In 2017, CHPP-1 generated 595 GWh of electricity and 1,195 GWh of thermal energy.
Riga CHPP-2 is the largest Latvian combined heat and power plant. It began operation in 1973. The reconstruction of Riga CHPP-2 was initiated in 2006, the ﬁrst power unit was commissioned in late 2008 and the second power unit was commissioned in late 2013, thus ﬁnalising the reconstruction of combined heat and power plants of the Group. The reconstruction allows for a possibility to generated electricity also in condensation mode, which is important for safety of power supply.
Currently Riga CHPP-2 has become the most efﬁcient and up-to-date combined cycle power plant in the Baltics. Two combined-cycle gas turbine (CCGT) units and ﬁve water boilers are currently exploited at Riga CHPP-2. Upon the commissioning of the second power unit, the electrical capacity of Riga CHPP-2 in cogeneration mode reaches 832 MW, while the total thermal energy capacity of the two power units reaches 544 MW in cogeneration mode. Electrical capacity in condensation mode reaches 881 MW. The full thermal energy capacity of Riga CHPP-2, including the boilers, is 1,124 MW.
In 2017, CHPP-2 generated 816 GWh of electricity and 1,545 GWh of thermal energy.