Flexibility of the Polish power system | Diagnosis, potential, solutions
Flexibility of the power system means its ability to maintain uninterrupted operation under conditions of rapid and huge fluctuations in electricity consumption generation. It is an inherent part of the system design and control of its operation. In the analysis, Forum Energii puts forward solutions supporting the improvement of the national power system flexibility. In addition to reducing the costs of the power sector and the improvement in quality and reliability of the electricity supply, their objective is to reduce emissions by the power sector.
In the past in Poland, it was provided by the centrally dispatched generating units. In the future, the share of variable renewable sources will grow. The electricity consumer will assume increasing importance. Thanks to the smart metering system and digitalization, the possibilities of improving flexibility are becoming a large resource. E-mobility and heating sector can be included to balance the national power system. Therefore, while thinking about flexibility, we should always look into the future.
The most important conclusions
- Considering the upcoming challenges, the Polish power system is insufficiently flexible.
- Consistently planned and implemented improvement of flexibility will increase the security of system operation and security of energy supply in a short-term perspective and will reduce the costs and CO2 emission over the long-term.
- The ability of the transmission system operator to make use of the flexibility of the power system users is limited. It is, therefore, necessary to increase the role of the operator who will reach for the flexibility resources connected to the grid.
- Increasing the share of renewable energy sources (RES) to 32% in 2030 in the Member States, which is the goal of the European Union, requires a constant reduction in the costs of these technologies. In this context, cost-effective and technically reliable integration of RES is very important.
- The operation of conventional and renewable sources need not be mutually exclusive and it is, therefore, necessary to change the entire supply chain: in conventional and RES production, transmission and distribution, to recipients and in regards to energy storage.
- Comprehensive market mechanisms should be implemented, the task of which will be to provide the entities who can offer operational flexibility with economic incentives.
Conventional generating units
Further revitalization of conventional coal units should be characterized by a short start-up time (within the desired three hours from the cold state), low technical minimums at 25% level and the ability to rapidly change load and to be adapted to frequent (about 200/year) start-ups assuming operation for fewer hours (about 1500-4500/year).
There should be a diversification in the use of fossil fuels towards the increase of the role played by gas sources, which are more flexible than coal sources.
The heating sector
We recommend the increase of the installed capacity of cogeneration sources to around 11GWe by increasing the efficiency of their use in the summer and replacing the withdrawn coal sources with steam-gas units (Combined Cycle Gas Turbine, CCGT). Adaptation of electricity production profiles to the recipients’ demand for power with the use of heat accumulation will help to fully take advantage of the potential of heating systems.
We recommend the consistent development of demand reduction mechanisms (Demand Side Response, DSR) towards the aggregation of smaller and smaller recipients connected to the distribution network up to individual recipients covered by advanced metering infrastructure (AMI). The flexibility obtained thanks to these mechanisms is a very important resource. The total potential of the reduction mechanism in Poland is estimated at a level of 2.5 GW with the availability of 1.2 GW.
The most important market mechanisms recommended for stimulating the behaviour of power system users are as follows:
- change of the energy pricing mechanism to include not only the costs of its production, but also its supply to the recipient. This will create the proper signals for network location and generation in a specific geographical area,
- development of short-term markets with higher liquidity, in which everyone will be able to participate on equal terms (producers, recipients, storage facilities), and the prices of electricity will reflect its value for the recipients,
- new tariff rules – introduction of real-time pricing.
Transmission and distribution
Expansion of the network is necessary in order to increase the geographical areas of balancing. We recommend the use of a dynamic transmission capacity assessment system that allows the transmission capacity of overhead power lines to be increased from a few to 30%.
There should be a shift from deterministic methods of network development planning to probabilistic methods allowing, among other things, for the changing nature of RES generation, various recipients’ demand for power and flexibility of power system users to be taken into account.
We recommend the increase of the distribution system operator’s competences in the use of regulatory services, especially in the context of solutions introduced by the Winter Package and changes related to the implementation of network codes developed by ENTSO-E, ACER and the European Commission. Modern RES technologies, in particular wind turbines and PV system, offer regulatory parameters corresponding to at least the technical regulatory requirements of system services defined by the transmission system operator, and for selected services they outweigh them. It is necessary that RES also take over the obligation to provide regulatory services, replacing conventional energy sources.
The first power market auction reported 15 installations with 111 MW capacity, which is a positive signal. It is necessary to enable the share of energy storage technologies on other markets, such as balancing market and regulatory services market, as well as production resources.
It is estimated that reduction of the daily load variability in the range of 5 to 25% (0.7-1.8 GW) can be achieved thanks to the development of e-mobility.
Due to the very early stage of this industry, its development must be stimulated towards full use of the potential of flexibility, in particular vehicles to grid technology (V2G) and price incentives in the processes of loading and unloading vehicles.
Title of the report: Flexibility of the Polish Power System | Diagnosis, potential, solutions
Date of publication: February 2019
Authors: mgr inż. Leszek Bronk, mgr inż. Bogdan Czarnecki, mgr inż. Rafał Magulski - Instytut Energetyki Oddział Gdańsk
Substantive supervision: dr Joanna Maćkowiak Pandera – Forum Energii