Thermal power generation technologies are widely used for electricity production, for heat provision in district or process heating systems, and for combined heat and power generation. In most cases, thermal technologies are heat driven and electricity is produced as a by-product, thus resulting in a non-flexible behaviour of the electricity production. Modern power grids are characterised by an increasing share of renewable leading to a need for enhanced and flexible ways of controlling the power flow. To provide services to the power grid, thermal generating technologies may be used in a more efficient way, coupled to gas and heat storage systems or aggregated in virtual power plants. Several technical factors determine which technologies are suitable for flexibility provision, including power ranges, start up times and ramp rates. In this work, carried out in the frame of the MAGNITUDE H2020 project, the technical characteristics of thermal sector-coupling technologies were analysed using data from the seven real-life project's case studies. The technical suitability was determined based on the product requirements in selected European power markets for the provision of identified system services. Expected future developments and trends were highlighted well.

Energy system integration between district heating and electrical domains is required for harvesting potential flexibility arising from sector coupling and support the transition to smart energy systems. This work presents a use case for using excess compressor capacity in refrigeration systems to locally couple district heating and electrical distribution networks by providing heat peak-shaving services to the district heating network. A tool-chain for explicit modelling of the electrical, thermal, and control domain using co-simulation is presented. It is based on a quasi-static electrical load flow model, a dynamic thermal-hydraulic district heating model and dedicated controller simulators integrated into the co-simulation information flow. The use case is implemented using the tool-chain and studied for different peak-shaving services request levels. The result shows that the proposed tool-chain is suitable for studying operational aspects of domain-linking components both at the network and the unit level. It is shown that the refrigeration unit can provide peak-shaving services while satisfying the primary cooling needs. Providing heat peak-shaving services allows distributed feed-in into the district heating network and potential new revenues. However, the refrigeration cycle coefficient of performance decreases as its operation changes from air/air to air/water mode.

The peak–valley difference of power grid will be enlarged significantly with the increasing number of integrated energy systems (IESs) connecting to power grids, which may cause a high operation cost and voltage violations. This study proposes an IES configuration method considering the peak–valley difference of the tie line between IES and power grid. An optimal configuration model of IES is established, which takes the sum of the annual operating cost of the power grid and annual cost of IES as objectives, while the tie line transmission power between IES and power grid are considered as constraints. The elite energy reserve genetic algorithm and branch and bound method are used to solve the proposed model, while the optimal power flow is used to calculate the grid operation cost under a given transmission power of the tie line. The simulation results of an improved IEEE30 node system verify the validity of the proposed method.

The growing interdependencies between natural gas and power systems, driven by gas-fired generators and gas compressors supplied by electricity, necessitates detailed investigation of the interactions between these vectors, particularly in the context of growing penetration of renewable energy sources. In this research, an expansion planning model for integrated natural gas and power systems is proposed. The model investigates optimal investment in flexibility options such as battery storage, demand-side response, and gas-fired generators. The value of these flexibility options is quantified for gas and electricity systems in Great Britain in 2030. The results indicate that the flexibility options could play an important role in meeting the emission targets in the future. However, the investment costs of these options highly impact the future generation mix as well as the type of reinforcements in the natural gas system infrastructure. Through the deployment of the flexibility options up to annual cost savings in planning and operation of natural gas and power systems could be achieved, compared to the case that no flexibility option is considered.

The study proposes the simulation study of a district-heating (DH) plant, located in the north of Italy, to provide automatic Frequency Regulation Reserve (aFRR). This work was carried out in the MAGNITUDE European project and consisted to model and simulate the plant. In particular, the plant devices were designed by grey-box models to replicate the behaviours. Also, the DH-network and the heat demand were modelled as functionality coupled to the device models. A multi-energy system (MES) plant manager coordinates the DH devices in a very short-term time interval while approaching and providing ancillary services. The designed models were simulated to replicate the basic behaviours of the plant. The outcomes were compared against the real plant time-series data set, showing a very good fitting. Afterwards, the plant provision of the aFRR market service was simulated. The results obtained showed how the coordinated devices satisfy the strict aFRR real-time constraints while supplying the DH-demand. The gained results go beyond the simulation case performed and suggest a two-fold perspective: the regulation has to pay greater attention to the amount of reliable regulating reserve arising from DH-MES and the DH-operators can increase the available resources to operate the plants.

Due to the increasing use of intermittent renewable generation, the power grid requires more flexible resources to balance supply and demand of electricity. Steam systems with turbine-generators, which are widely used in industries, can be operated flexibly to support the power grid. Yet, the available amount of flexibility of industrial steam systems is still not clearly quantified. This study presents the method to quantify electricity generation flexibility of a typical industrial steam system with a steam turbine-generator and process heat demands. The proposed method is introduced based on a real case of an integrated pulp and paper mill in Austria. An integrated mathematical model representing the combined electricity and steam system is developed to simulate the behaviour of the on-site energy system to quantify the potential flexibility provision. Flexibility is represented as the maximum upward and downward changes in the imported electricity from the public power grid. The results demonstrate that it is possible to aggregate the flexibility of the industrial facility as a lookup table. Also, the results reflect key factors that limit the flexibility at different operating points of the turbine-generator.

With the increased share of renewable energy sources, there is a growing need for more flexibility to ensure the efficient and reliable operation of the electricity system. Multi-energy systems (MES) now appear as one possible means to provide such flexibility through increased synergies between electricity, gas, and heating/cooling systems. In this context, the main findings of the study carried out in the MAGNITUDE European project are described. The most relevant services that could be provided by MES to the electricity system are first presented. Then a methodology is proposed to characterise and compare the market organisations and mechanisms for their procurement. The results of its application in seven case study countries are summarised and illustrate the diversity met between countries. The gas and heat sectors are also investigated for the seven countries to characterise the main aspects relevant to the provision of the services by MES. A comparative analysis is then carried out between the three energy sectors in the seven countries and highlights the major similarities and differences. Finally, potential barriers for the provision of the services by MES are discussed regarding the market, regulatory, and cultural aspects.

Developing automation solutions that enable remote communications, monitoring and control for subsea applications are key steps in designing subsea power distribution systems. These systems require fast local control to protect the multiple electrical loads and the capability of transferring prompt real-time trip signals. This study introduces a data-driven distributed fault detection and identification algorithm to monitor multiple subsea loads. The proposed scheme is divided into three steps. First, a stochastic hidden-Markov model (HMM) is developed to model the dynamic evolution of different potential conditions of multiple subsea loads. Simultaneously, the second step computes a model of the transition probability between the current operating condition and the potential response of an individual load. In the third step, using real-time measurements, the HMM is updated to predict an unobserved degradation of the load's current condition. This is achieved through an integrated perturbation analysis and sequential quadratic programming method. An assessment of case studies on subsea AC power system is presented, which includes different subsea motor loads for compressors and pumps. Results show robustness against uncertainty in measurement noise and changes in equipment mean time between failures, providing enhanced reliability.

Future plans for integration of large non-synchronous generation and the expansion of the power system in the Nordic countries are a concern to transmission system operators due to the common interconnections and electricity exchanges among these operative areas. The expected reduction in the inertia anticipates an alteration of the frequency response, provoking a high Rate of Change of Frequency (RoCoF) slopes that can jeopardise the security of the interconnected systems. Since power generation in the Nordic countries such as Sweden, Finland and Norway is hydro-dominated, here, the authors propose a novel solution to tackle this problem including wide area measurements to monitor and share the RoCoF in remote areas with lower inertia to enhance their primary frequency control. To demonstrate the effectiveness of the proposed solution, first a test benchmark control with optimised parameters is developed and later compared against the proposed method. Additionally, since the proposed solution is based on measurements from remote locations in order to guarantee the stability of the system the impact of delays in the communication channels is also included in the problem formulation.

This study proposes a solar photovoltaic (PV) based nanogrid with integration of battery energy storage to supply both AC and DC loads using single-stage hybrid converter. A boost derived hybrid converter (BDHC) is used as a single-stage converter to supply the AC/DC hybrid loads. The BDHC reduces the number of conversion stages when compared to the conventional solar PV based systems to supply the AC/DC loads. A non-isolated buck–boost bidirectional DC–DC converter is used for charging and discharging of the battery to support the nanogrid. The power reference algorithm proposed in this study provides the proper utilisation of the solar PV in different operating conditions and uninterruptable power supply to the loads along with the battery storage management. A modulation scheme is implemented to operate the BDHC for generation of AC/DC hybrid outputs from a single input. The performance of the proposed system in different modes of operation has been evaluated using PSCAD simulation studies. A laboratory experimental setup is developed and control algorithms are implemented using LabVIEW based FPGA controller for verification of the results.