An onshore high-voltage, direct current electric power transmission cable (HVDC) is the most spectacular proposal included in the draft Grid Development Plan prepared by Polskie Sieci Elektroenergetyczne (PSE, Polish grid operator). The document provides many analyses and a lot of key information about the future of the Polish power industry. It also heralds huge changes in the government’s energy policy. In the perspective of 2030, it is even possible that renewable energy sources will exceed 50 percent in the share of electricity produced in Poland – expects Daniel Radomski, contributor to BiznesAlert.pl.
Energy demand forecast
For the first time, the impact of widespread deployment of electric vehicles, heat pumps and hydrogen technologies on the growth of demand for electricity has been taken into account in official planning documents. The year 2021 ended in this regard with 174,4 TWh. It is expected that by 2050, depending on the scale of hydrogen production, that figure will jump to 300, or even 500 TWh. This means Poland must not only restore its production capacity in non-coal technologies, but also double, or even triple them. We will therefore need much more green and nuclear power than the current government energy policy reveals.
Annual electricity demand resulting from hydrogen production. Bar chart by Polskie Sieci Elektroenergetyczne.
Fit For 55, or a rapid development of RES and a gas trap
Initial estimates for the implementation of the Fit For 55 package, assuming the ETS system will be extended to road transport and buildings, suggest that 42 percent of electricity will come from renewable sources in 2030, with annual demand of around 200 TWh. The proposed fuel mix implies a 4.5 fold increase in energy generated from natural gas in comparison to 2020. The analysis expects an increase in the installed capacity of onshore wind farms from 6.5 GW to 18.4 GW, which means the authors assumed the so-called “10H rule” will be abolished.
In December 2021, the Prime Minister appointed an Expert Team for the Construction Of Pumped Storage Plants. At the first meeting in January, the team discussed the continuation of construction of a 750 MW pumped storage plant Młoty (ESP Młoty) near Kłodzko, which had been suspended in 1981. PSE proposes the construction of a 400kV line Świebodzice-Ząbkowice-Dobrzeń for power take-off from the Młoty plant. The investment is expected to be ready in 2029, provided the plant is built. Areas with particularly high power consumption can be interpreted as potentially attractive locations for the implementation of urban nuclear heat and power plants.
Map of power flows
Data that are particularly valuable have been presented graphically. The numerous wind power sources that are located by and on the sea will feed a lot of power into the system in the north. At the same time, many coal sources will be shut down in the Upper Silesia region. Therefore, it will be necessary to significantly improve transmission capacity along the north-south axis. This is the direct, but not the only, reason for the construction of the HVDC link.
Onshore HVDC lines
The direct current connection between the coastal wind turbines with the Upper Silesian Industrial Region with a capacity of 4GW is to be ready for 2033. That’s when the first unit of the seaside nuclear power plant will be commissioned as well. PSE has announced that it is already considering more HVDC interconnections in its analyses for the 2040s. However, they will not be built as links connecting 2 points, instead they are expected to have intermediate points with branches.
The connection will reduce the load on the AC network, increase the stability of the grid and will be less expensive than the construction of several AC lines, it will also allow to control the flow of power and reduce the need for the installation of synchronous condensers.
Power evacuation for the NPP
The investment was divided into three phases. By 2026, an ELJ station will be built to receive power from the nuclear power plant, but in the limited range of a 110kV switchboard, and a 110kV connection. The investment will be used to power the construction site. In the second phase, by 2032, a 400kV distribution line will be built, two double-track lines will be extended to bring power to the new DSC station between Żydów and Gdańsk, as well as a line connecting this station with the area near Grudziądz. Depending on the chosen technology, this will allow one or two reactors to be connected. In the third phase, a line will be built connecting the DSC station with the areas around Konin. This will make it possible to receive the full planned capacity from the first nuclear power plant – 3750 MW. The total cost of implementing all of these phases will be about PLN 3 billion.
750kV in a new incarnation
The area of the podkarpackie voivodship between Rzeszów and the border with Ukraine needs to have its power supply security improved. The plan also involves a build up on investments areas. For these reasons, a line with a voltage of 400kV will be brought to the town of Jarosław. For this purpose, PSE wants to use the existing elements of the former 750kV line connecting Rzeszów with the Khmelnytskyi nuclear power plant in Ukraine. However, this does not mean the cross-border link will be reactivated. The line will be adjusted to a voltage of 400kV and connected to a new power station in Jarosław. The investment does not exclude future synchronous cooperation with the grid in Ukraine.
Yet, it should be stressed that a significant part of the PSE document related to the development of the transmission system had been prepared in 2021, and the entire technical analysis had been carried out before the war erupted. Recently an emergency connection between Ukraine and the European synchronous area has been established. This may impact Poland’s and EU’s approach to the possible reactivation of the connection with Ukraine.
Managing reactive energy
Once old coal power plants are shut down, it will be possible to use the remaining generators as synchronous condensers to regulate the flow of reactive energy, which will improve the security and stability of the grid in extreme situations. A far-reaching expansion of the transmission network will increase the risk of surges, due to excess reactive power in the network. The problem will be significantly reduced thanks to the construction of HVDC lines, but it will still be necessary to implement compensating appliances. The solutions are to be implemented by 2032. The issue of passive energy management is also taken into account when synchronising the Baltic states with the ENTSO-E area.
Planned energy storage
Investments in battery energy storage are not a foregone conclusion, but the sole fact that they are included in the PSE plan indicates it is very probable they will be implemented and that their scope will be significant. Energy storage units could be built in Turośl Kościelna near Białystok, in Siedlce, Ełk, Kozienice, Mieczysławów near Pątnów and in Kartoszyn near Żarnowiec. The PGE Group has announced the construction of an energy storage facility in Żarnowiec with a capacity of 205 MW and storage capacity of 820 MWh.
TSO’s own capacity
Economic analyses and the results of the December capacity auctions, which in the first round concluded with prices reaching PLN 400 kW/year, prompted PSE to invest in its own sources, which would operate only in situations of extreme weather conditions, limited availability of imported electricity or increased unavailability of conventional generation sources. For this purpose, PSE wants to build one or more power sources that will run on gas or a liquid fuel, and will be based on a gas turbine or a reciprocating engine with a total capacity of 500 MW, or alternatively storage facilities with the same capacity and capable of providing energy for 8 hours. At the same time, PSE concludes that the projects that are most likely to be implemented will pertain to cogeneration sources at locations where there is demand for heat, as well as sources with parameters that will ensure efficient work as base or peaking plants. In this respect, this is another argument for long-term investments in urban nuclear heat and power plants.
Powering high-speed rail
The new high-speed rail lines built by the Central Communication Port (CPK) are to be implemented with 25kV AC traction. Thanks to this, the new tracks will be able to run locomotives with much more power than a 3kv DC traction. At the same time, this will reduce the cost of construction and operation, because substations can be located at greater intervals, and lower operating currents mean less transmission losses. However, in order to benefit from these advantages, the railway must be supplied directly from the transmission system, via separate subscriber lines with a voltage of at least 220kv. This means the CPK has to agree on its plans with PSE. To this end, CPK designed and agreed on with PSE a proposal for a power supply system for a new railway built for the new port.
Out with coal and gas
The PSE forecasts are very optimistic and prepare the National Power System for all possible scenarios. However, achieving a 50 percent share of RES will entail huge costs: 32 billion for the transmission system – including 3 billion for the connection of the nuclear power plant – and 100 billion for the development of distribution systems. In total, this will allow up to 46.5 GW of renewable energy to be connected by 2030. These costs will be borne by end users in the electricity bill, including the costs of building and maintaining PSE’s own sources.
Connecting new nuclear power plants, including small reactors, should be almost cost-free – they will be built in the area of existing nodes of the transmission or distribution system. Therefore, in order to reduce the share of coal and gas in the energy produced, at the lowest possible overheads, it would be necessary to set a target mix of different types of energy sources and storage and adopt the most “degasified” strategy for the heating sector. Doubling down on nuclear power, pumped storage plants, energy storage facilities and heating pumps is truly a necessity.