Abstracts - VGB PowerTech Journal 12/2017

VGB`s Technical Services: A successful service for power and heat generation

Christian Ullrich

VGB’s Technical Services are an important part of the service of the VGB PowerTech association. They are to be regarded as an en-hancement to the services for our members and cover many aspects of technology and operation in power and heat production. [more...]

The transformation of the European utility landscape

Christophe Brognaux, Jens Burchardt, Jérôme Hervé, Frank Klose, Jan Limet, Tobias Pfingsten, Dominik Thiel and Ferdinand Varga

For decades, the story in the European utility industry has been the same: Large, vertically integrated utilities invested in and managed hard assets such as power generation plants and electric grids, earning stable returns. And investors looking for predictability made utilities a key component of their portfolios. Today, virtually every aspect of that story is being rewritten. Among the most powerful forces altering the industry in Europe and elsewhere are stagnating demand, the shift from conventional to renewable energy, and the growing popularity of distributed power, which allows users to generate energy on their premises. As a result, the profit pools for utilities will shift dramatically. So, too, will the sources of competitive ad-vantage – and success will demand new capabilities. This is true for emerging opportunities such as decentralized solutions, but even traditional segments will require new approaches. To succeed, utilities must decide which segments to focus on, shedding those that will not be strong earnings contributors and developing an investment thesis based on a clear vision. They must also improve the efficiency of their core operations. While many utilities have cut costs, they must make even more drastic changes. And, perhaps most critical, they need to become more agile. Those that fail to make this switch will invite shareholder revolt – and the necessary changes will be forced upon them.

Download [2.7 MB]

Detailed verification procedure for power generation plants with directly grid-connected synchronous generators in Germany

Philipp Reindl and Julian Langstädtler

The German grid code compliance assessment procedure poses a challenge for manufacturers and operators of large synchronous generator power plants: The requirement to assess the dynamic behaviour during voltage dips (Fault Ride-Through – FRT) by performing type testing is often impossi-ble. On the one hand proper test equipment is lacking for powerful generators while on the other hand testing can also lead to significant impacts on the connected power system. An alternative method for conformity verification is established with the multistage individual procedure for compliance assessment. In this regard a preliminary conformity study based on plant simulations is firstly used as basis for the preliminary plant certificate, which leads to an interim operational notification for conduction of field tests. These alternative tests substitute the FRT measurements but allow the docu-mentation of the plant’s control capability, system perturbations and form the basis for simulation model validation. This enables conducting the final conformity study and thus issuing the final plant certificate, now containing valid forecasts of the plant’s behaviour during relevant operational scenar-ios. This rather new procedure is relatively unknown to many experts in the sector of conventional power plant development. However, their expertise is of high relevance for the successful project realization. Therefore, the following article shall contribute to a further awareness of this complex topic.

ČEZ’s Hydropower Fleet – past, present and future – Current utilisation and prospective new projects

Petr Maralík, Roman Mašika and Václav Lagner

ČEZ belongs to experienced energy companies with a deep tradition. Current company roots of ČEZ have been formed in 1946 when during couple of next years smaller generating companies have been integrated to a one big corporation dedicated to generate, distribute and transmit the electric power. Then in 1992 ČEZ company has got its name and structure at the new era. The actual power mix of ČEZ consists of coal, hydro and nuclear generation, last years also brought renewables into energy production mix; next to it, the company provides energy distribution services, district heating, has its lignite mining company and provides further energy related services. The company has an installed power capacity 21,856 MW, where 49 % is generated from coal (mainly lignite) and hydro including pump storage.

Download [2.5 MB]

Instant performance at the push of a button – Boost the opportunities of your plant with hybrid solutions

Stefan Alwers and Uwe Fuchs

Conventional power plants remain indispensable despite the socially desired expansion of renewable energies, in order to maintain grid stability and security of supply on the previous quality level. Nevertheless, conventional power plants are required because they provide for the frequency mainte-nance by virtue of the rotating mass of their synchronous generators. However, as a result of the priority of renewable energies, there is less and less rotating mass available. In addition, conventional power plants require a certain period of at least 5 to 10 minutes to start – too much time to react quickly to load changes with high dynamics. One given solution to this problem is large stationary battery storage systems (BESS), which can realize response times of less than one second. Their performance is immediately available. Having appropriate design, BESS can supply both charge and dis-charge energy to the power grid and support the start-up of gas turbines. In combination with a storage, gas turbines are black-startable and can thus restore the network in case of serious disturbances. Against this backdrop, Siemens has developed hybrid solutions called SIESTART from gas turbine or combined-cycle power plants and battery storage systems, they base on validated elements of the own portfolio and some of the use-cases have already been implemented in several European countries.

Flexible power plants – Economic low load and house load operation with coal

Reinhard Leithner and Niels Oliver Brinkmeier

The paper starts with explaining the general relationships between power, steam flow, temperatures, pressure and pressure drops of steam generators and steam turbines at part load for different operation modes like fixed pressure operation, natural and controlled sliding pressure operation and constant pressure operation. Especially the following challenges of an economic low load, idle load or house load operation and potential solutions are described: Reduction of the minimum once through load including reduction of the temperature differences at the evaporator outlet by throttles and valves and its influence on life-steam and reheat steam temperature change with the load, keeping high life-steam and reheat steam temperatures by bypasses, reduction of the minimum mill load, reduction of start-up time and using heat storages.

Manufacture of disposable containers for low and medium level radioactive waste for disposal by the Federal Authorities

Anton Philipp Anthofer, Max Schreier and Johannes Schubert

Duly compiled and approved repository documentation is required for the delivery of radioactive waste to the Konrad repository. The German Act on Reorganization of Responsibility for Nuclear Disposal (Entsorgungsübergangsgesetz (EntsorgÜbG)) adopted in June 2017 provides the energy utilities with the new option of transferring responsibility for their waste packages to the Federal Government. This is conditional on the waste packages being approved for delivery to the Konrad final repository. At the Lingen, Hanau and Karlsruhe locations, waste packages have already been produced which have received the corresponding approval or will receive it shortly. In these examples, all aspects relevant to final disposal have been implemented in the process qualification before the start of the physical measures. A comprehensive approach starts with the dismantling of nuclear facilities and extends from waste disposal and packaging planning to final repository documentation. Waste package quality control measures are planned and im-plemented as early as in the process qualification stage so that the production of waste packages that are suitable for final deposition can be ensured. Optimization of cask and loading configuration can save container and repository volume. Workflow planning also saves time, expenditure and expo-sure time for personnel at the facilities. VPC has evaluated this experience and developed it into a comprehensive approach, covering planning and selection of the dismantling methods and techniques, selection of the waste container, and packaging planning and repository documentation.

World Nuclear Performance Report 2017

Jonathan Cobb

World Nuclear Association recently published the 2017 edition of the World Nuclear Performance ­Report. The report presents key metrics that ­illustrate current performance, both of reactors ­currently operating and those under construction. The article highlights some of the most important findings of the report. The pace of new build will need to accelerate if nuclear energy is going to make a growing contribution to the global electricity ­generation mix, a requirement of many projections of future scenarios that aim to meet the objective of limiting the rise average temperatures to below two degrees Celsius, while at the same time meeting the growing worldwide demand for electricity.