Modelling the Polish energy system – new findings of PyPSA-PL


Ensuring the provision of energy at all times and places is a challenge for energy systems with a large share of variable renewable energy sources (RES). The issue is the subject of heated public debate, with reasoned arguments highlighting both the advantages and limitations of these sources. However, balancing these arguments – that is, answering the question of whether RES can plausibly have a significant share in the Polish energy mix – requires a more comprehensive analysis using tools suitable for this purpose. The PyPSA-PL model, being developed by Instrat, is just such a tool.

The world is changing and modelling needs to keep up with it

The first version of the PyPSA-PL model was developed in 2021 and provided arguments for the claim that 70% of electricity generation from RES in 2030 is a feasible target – which would significantly reduce greenhouse gas emissions and contribute to the EU’s climate targets. However, the world is changing rapidly, forcing our tools to be continually updated. Price shocks in fossil fuel markets caused by the Russian invasion of Ukraine must lead to a revision of assumptions about the costs and prospects for conventional energy sources. Likewise, the Polish electrical power system has changed since 2021 – despite unfavourable RES legislation, we see a clear trend of increasing installed RES capacity in the national mix. At the same time, our tools must respond to the needs arising from the current public debate. One important topic is the challenges of flexibility in the electrical power system: in the following, we briefly present how we address this issue in the latest version of the PyPSA-PL model.

New flexibility options in PyPSA-PL

The first major improvement to the PyPSA-PL model is a more detailed representation of electric power systems in neighbouring countries taking into account the breakdown by generation technology. This allows us to model bilateral electricity trade dependent on weather conditions and instantaneous electricity demand. Cross-border electricity exchange not only improves the energy security in Poland through imports in case of low domestic generation but also increases the profitability of our RES installations, as a surplus generation can be sold abroad. A more realistic representation of electricity trade in the PyPSA-PL model is particularly important in the context of year 2030, when we expect that net electricity imports may satisfy as much as 10-15% of domestic demand.

The second new functionality in the PyPSA-PL model is the inclusion of the need to continuously provide a power reserve of 9% of instantaneous demand. The 9% power reserve condition is a standard set by the Polish transmission system operator, PSE, and, importantly, this reserve can only originate from large conventional generation units (currently mainly fossil fuel and, to a small extent, biomass) which are operating and energy storage facilities (currently pumped storage hydropower plants). The condition for a power reserve defined in this way means that controllable conventional units must operate in the system even when RES could cover the entire instantaneous electricity demand. This is a barrier to the development of RES, which could be alleviated by creating regulations that allow the provision of the power reserve service by controllable RES units such as small biogas or biomass power plants, as well as by wind and solar sources that could operate at a reduced capacity in coordination with the dispatcher.

Sector integration as key to an effective energy transition – a call for collaboration

Our modelling so far has focused on the national electric power system. However, the energy transition’s success will only be possible if the electricity sector is integrated with other sectors of the economy, such as heating, transport or heavy industry. We, therefore, want to orient the further development of the PyPSA-PL model towards the inclusion of further sectors and the analysis of energy flows between them hour by hour. Given our plans to expand the model, we invite energy modellers and sectoral experts to share their suggestions and comments on our work, and even to become more actively involved in the expansion of PyPSA-PL. A unique advantage of our model is its transparency and open access to input data and source code*, which encourages knowledge exchange and informed discussion.

* The source code and input data for the latest version of the PyPSA-PL model will be made available in February 2023


Patryk Kubiczek, Energy modelling expert,

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