This presentation ‘A TSO Strategy to Boost Decarbonisation and Development of Renewables’ consists of 8 PowerPoint slides as pdfs.

Secure Energy Transitions in the Power Sector reviews the tools necessary for power systems to prepare for upcoming changes in the power sector landscape, including the increasing penetration of variable renewable energy sources, distributed energy sources, network-connected devices and changing climate patterns, that will affect the provision of electricity security as energy systems decarbonise. Systems will need to adapt new methods of monitoring security of supply, while encouraging investments in key system services, like stability, flexibility and adequacy. This can be done by creating well-designed markets that minimize economic costs through unlocking latent sources of flexibility. In addition, systems should pursue interconnections with neighbouring systems to take advantage of complementarity and enhance coordination between the gas and electricity sectors in order to increase security and lower overall system costs.

The process for the exit from coal-fired Generation in Germany is fixed by legislation until 2038. Accompanied by other ongoing changes due to the German energy transition (“Energiewende”) to achieve the European climate and energy policy targets this causes comprehensive challenges for the transmission system and its future operation. Therefore, the German legal framework for the coal exit comprises the obligation for the German TSOs to provide a longterm analysis about system-technical aspects during the coal exit including the relevance and urgency of regular accompanying analyses and the challenges for grid restoration. Moreover, conclusions for crucial need for action with regard to regulation and network codes on national as well as ENTSO-E level have been identified. Finally, for the actual prognosis for the year 2028 an interim checkpoint for consequences of the coal exit has been investigated in detail. This paper summarizes the results of all of this analysis carried through under the responsibility of the German TSOs with the support of other experts. Since from a technical point of view the coal exit mainly implies less synchronous generators and turbines with high inertia operating in the system, less weather- and time-independent generation and changes in power flow patterns, the results are undoubtedly of general interest due to similar consequences of transition processes throughout the world.

A 3-part document series entitled “Recommended Practices for Selecting Renewable Power Forecasting Solutions” (RP-FSS) was compiled through a collaboration of an international group of experts under Task 36 of the IEA Wind Technology Collaboration Programme (IEA Wind TCP). The ultimate objective of the RP is to assist the forecast users in the selection of an optimal forecast solution for their specific set of applications. The need for the RP was based on considerable evidence that even though renewable energy forecasts are now widely employed for operational decisionmaking the full potential value of the forecasts is frequently not realized for many applications. The group initially identified three key contributing factors: (1) the specification of the wrong forecast performance objectives in the forecast solution selection process, (2) the use of poorly designed benchmarks or trials to select a forecast solution for the user's application and (3) the use of non-optimal evaluation metrics to assess the performance of candidates or existing forecast solutions.

The International Energy Agency (IEA) Wind Task 36 on Forecasting for Wind Energy organises international collaboration, among national weather centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, ...), forecast vendors and forecast users to facilitate scientific exchange to be prepared for future challenges.

The talk discusses the general setup of the Task, and the latest developments. Among those are decision making under uncertainty. To this aim, actual forecasting situations were gamified and was tested by a wide audience. During the game, the participants could experience the benefit of probabilistic information on their decisions to trade.

A major effort of the Task is the IEA Recommended Practice for Forecast Solution Selection which is divided into 3 parts: (1) “Forecast Solution Selection Process”, (2) “Designing and Executing Forecasting Benchmarks and Trials”, and (3) “Evaluation of Forecasts and Forecast Solutions”. The group initially identified three key contributing factors for failing to get the optimal value from the forecasts: (1) the specification of the wrong forecast performance objectives in the forecast solution selection process, (2) the use of poorly designed benchmarks or trials to select a forecast solution for a user's application and (3) the use of non-optimal evaluation metrics to assess the performance of candidates or existing forecast solutions. For this year, we intend to update the guideline in the light of the experiences throughout the industry in its initial application, and after collecting this experience at 3 Open Space workshops. A fourth part will be added, extending the guideline to Measurements for Real-time Forecasting Applications.

Another current activity of the task is the Numerical Weather Prediction (NWP) benchmark. NWP model providers have been asked to run two well-measured sites. One is from the Wind Forecast Improvement Project 2 and represents a difficult case of mountain waves in the US, the other one is based on a week of data from an offshore wind farm in the Baltic. A common validation framework was developed for that case and is available from Github.

Finally, we submitted a paper on the uncertainty propagation throughout the entire modelling chain, where we investigated the part of the uncertainty that is coming from the model, that of the model inputs, and the part that is weather related. The analysis is done separately for the planning phase, operational phase and market phase of the plant and forecast system.

The German target of a zero-carbon energy system by 2050 comes with the challenge of increasing electricity demand and thus needed acceleration in renewable capacity installed. Depending on the consulted study 10-15 GW PV and 6-8 GW Wind will be needed as new installations each year. With an increasing amount of fluctuating renewables, we will see a blockage for grid connection offers for each individual project. Meanwhile Therefore, it is suggested to use the complementary generation profile of wind and PV plants at one grid connection point without increasing its overall maximum power. With such a combined plant of similar sized projects in Germany the utilization of that point expressed in full load hours can be increased by 10-15 % resulting in an increase in energy injected by more than 50% based on the wind production. The investment and operation cost of the overall project can be reduced so that the overall generated kWh in the lifetime of the project cost less. This is a win for the project owner but also for the overall economy with less subsidies required to finance the project. Further optimization could be reached through a hybridization with a storage system.

Technical analyses from several European transmission system operators (TSO) expect a significant decrease of system inertia after 2030, due to the large integration of power electronic interfaced generation units and a simultaneously decreasing share of synchronous power generation units. Therefore, TSO need to initiate measures, securing the future power system stability. A well-discussed and promising approach is the integration of assets with grid forming capability (GFC) into the transmission grid, providing grid services as inertia provision and voltage formation in order to stabilize the grid in critical situations. To support the TSO in their responsibility to ensure security of supply, storage facilities could be a promising option to explore. Storage facilities could play an important role in delivering grid-forming capabilities in the future. The maturity of the technology is high, and battery storage facilities could already today offer grid-forming capabilities.

The work examines the Continental Europe power system for an actual split event occurred in 2021. The behaviour of the system after the split is first replicated with a specific dynamic simulation model. The validated model is then further developed and extended to investigate the frequency dynamics of the split event, assuming the European system in a scenario characterized by high integration of renewable energy sources interfaced through power converters. The implementation of the non-synchronous generation sources in the simulation model of the system is realized considering two different control concepts for the converters, a grid-following and a grid-forming control. The simulations are performed for different values of relevant parameters for the converters control and different operating conditions for the non-synchronous generation sources. Analysis and results suggest that the integration of non-synchronous generation sources might not necessarily imply only challenges, but rather they can participate in the frequency control and provide an essential contribution to the frequency stability of the system, especially under critical conditions like the system separation.

Power system planning plays a key role during the clean energy transition to ensure the cost-effectiveness and the security of supply. Traditionally, the primary focus of power sector planning was on expanding supply infrastructure to meet projected electricity demand. With the changing landscape of the power sector, planning for a future power system needs to become more sophisticated by taking into account the role and impact of such developments as the uptake of VRE, distributed energy resources and electrification. This allows appropriate investment decisions on generation, grid infrastructure and other flexibility options. Better integrated and coordinated planning frameworks can help identify appropriate options for future power systems. The process should take into account questions of flexibility and reliability, and how different supply- and demand-side resources can play a role. Integrated planning framework encompasses a number of elements: integrated generation and network planning; integrated planning incorporating demand resources; cross-sectoral planning between electricity sectors and other sectors, particularly heating and cooling and transport sectors; and planning across different regions and balancing areas. Probabilistic analysis approach can enhance adequacy assessment and power system planning by providing a more detailed picture of the reliability of a power system allowing for more precise reliability target.

The building sector plays a significant role in the German Energy Transition. It consumes over a third of the ultimate energy demand, most of it coming from fossil sources (oil, natural gas, etc.). Over 90 percent of this energy is going into space heating and hot water production.

Buildings and their heating systems offer though various opportunities to flexibly store and convert energy, e.g. by using excess electricity from wind for hot water production and heating (power-to-heat). The presentation offers insights and results from a trial site in Berlin, Germany. In a neighborhood smart building technology was used to increase flexibility and the capability of the buildings to store excess electricity from renewable sources and to convert it into heat. Trigger for the conversion are price signals from an aggregator (flexibility trader).

Results show that in combination with conventional measures (building envelope and efficient heating) such buildings/neighborhoods can almost achieve climate neutrality. In addition, the concepts allows to increase the share of wind power used in buildings and foster grid stability by providing storage capacity and balancing power on the local/regional level.