EPV Alueverkko’s substation was completed on the 17th of July, ready for commissioning, at the Heinineva solar park. The substation will be used to transmit electricity generated by the EPV solar farm to the grid. The main contractor for the substation project was Nordic Electro Power Oy.
The actual construction of the substation started in September last year. Jukka Paavola, Chief Executive Officer at EPV Alueverkko, says the schedule was exceptionally quick, as substation construction projects normally take about two years. He points out that the construction went according to plan at every stage.
“The project proceeded extremely smoothly, both in terms of the building work and equipment delivery. Nordic Electro Power was responsible for the earth-moving and electrical engineering work, all equipment supplies except the transformers, and the construction and installation of the equipment. The transformers were supplied by BTB Transformers,” Paavola explains.
The new substation includes two transformers, four 110 kV switchyards, two equipment buildings and two 33 kV switchgears. Electricity is transmitted from the solar park through underground cables. Initially, the electricity generated by the solar panels will flow from the blocks to the substation’s switchgear. From the switchgear the electricity is transferred to transformers which convert 33 kV electricity to 110 kilovolts, after which the electrical energy generated will be transferred to the grid.
Electricity transmission to start this autumn
Paavola mentions that the substation differs from EPV’s usual substations that connect and transmit electricity mainly in terms of the automation that EPV uses in solar power generation. EPV has put a lot of effort and resources into ensuring the safety of the substation’s operations and the transmission of electricity.
“The construction of two equipment buildings is in itself a safety measure. We want to ensure uninterrupted power supply as far as possible, should one of the equipment buildings or medium-voltage switchgear be out of service for some reason. All the systems are duplicated, meaning that the failure of one device or system will not interrupt the solar farm’s electricity production or the transmission of electrical energy to the main grid,” says Paavola.
Right now, in the initial phase, the substation transmits electricity to the solar farm building site. Paavola expects the transmission of electricity to the grid to start in September, when the park’s first solar panels will be ready to start generating electricity. This will allow EPV time to monitor the transmission of electricity to the substation and from the substation to the grid and to make sure everything works as planned.
“The substation will eventually transmit all the electricity generated by the solar panels. In the beginning, however, it is easier to monitor and control the electrical energy produced when new parts of the solar park that are producing electricity are connected to the grid, one completed area at a time. This allows us to ensure that everything goes according to plan and that, for example, voltage regulation works flawlessly,” Paavola says.
Additional information: Jukka Paavola, Chief Executive Officer, EPV Alueverkko Oy, +358 10 505 5035