Abstracts - VGB PowerTech Journal 8/2014
The transition of the energy supply system with regenerative sources and safety of supply and system stability
Harald Weber
The transition of the energy supply system to regenerative sources emerges some questions concerning the stability of the system because conventional power plants will be shut down: power balance stability, voltage stability, primary control stability and inter area oscillations. With the disappearance of conventional power sources, power system stabilisers will also disappear but the existing power flows in the network remain. This will result in increased occurrence of inter area oscillations in the system which can only be avoided by installing these devices in the new regenerative sources.
Market conditions of the “Energiewende”
Fabian Grote, Christian Kraemer and Albert Moser
For the future generation system with a large share of renewable energy sources, new technological and economic challenges especially for thermal power plants arise. The lower residual load goes hand in hand with falling market prices for electrical energy. Exemplary investigations conducted for this paper show contribution margins and profitability of the German power plant portfolio in the year 2023 in different power market designs.
Future developments within the “Energiewende”
Harald Thorwarth
The most important goal of the “Energiewende” is the conversion of the German energy system into a sustainable energy supply system. As a consequence, the “Energiewende” is not restricted to electricity production, but concerns energy supply in general. Germany is still at the very beginning of this process. Regarding primary energy consumption, biomasses are the most important resources among the diverse renewable energy sources. At present, the increasing electricity production from wind and photovoltaic plants decreases the economic viability of electricity storage plants as well as fossil-fuelled thermal power stations. With increasing electricity production from wind and solar plants, there will be more and more time when production exceeds consumption. This will be the chance to convert this electricity into hydrogen or methane.
Influence of increasing intermittent generation on stationary and dynamic grid operation
Florian Gutekunst and Simon Remppis
In order to achieve the goal of the European Union (EU) to cover 20 % of the primary energy consumption by renewable energy sources until 2020, the penetration of renewable electricity generation must be significantly raised in comparison to the current level. The integration of this increasing share of intermitting generation confronts the existing power system with a big challenge. Possible results of an increasing share of intermittent generation are shown and the resulting influences on both stationary and dynamic grid behaviour are analysed. For this purpose the simulation results for an off-peak load situation are shown in detail.
Impact of elevated Rate of Change of Frequency (ROCOF) on conventional power generation plant in the island of Ireland
Marios Zarifakis and William T. Coffey
In a changing electricity market invariably demanding an increase in the energy generated by sustainable sources, wind turbines and solar photovoltaic installations represent major contributors to the energy generating portfolio. However, such sources have a direct bearing on the frequency stability within the transmission and distribution network. In the light of the newly available sustainable sources, the effect of an increase of ROCOF from currently 0.5 Hz/s to 1 Hz/s on the conventional larger fossil fuel-fired turbo and hydro generators run by the Electricity Supply Board (ESB) is investigated.
Performance indicators of wind turbines – The KISSY-System of VGB PowerTech
Jörn Rassow
The VGB Project Group “KISSY/Wind Energy” is aiming at pointing out weak points of wind turbines to improve operation. The project group will install a systematics for availability and unavailability as basis for statistical and technical scientific analysis. Data are recorded in the existing KISSY power plant information system in order to enable cross-utility analyses. KISSY is currently being extended for wind power plants. First examples show that quantification of operation is possible.
Maintenance and life time forecast of civil structures in power plants
Olaf Day and Martin Demmer
For existing structures and buildings there is often an implicit demand that systematic measures like inspections and maintenance are not necessary for such structures. A practical example will demonstrate an investigation methodology based upon life time management in the field of power plant construction/associated infrastructure. With this approach initial good findings regarding the preser vation status of a building can be obtained. By continuing these investigations, either in a cyclical manner or over the course of a monitoring process, it is then possible to make further forecasts concerning the life time or the required preservation measures and, as a result, with regard to the required investment or maintenance volumes.
Maximising the net electricity production of CHP units through thermo hydraulic optimisation of the district heating parameters
Jörg Sager
Net electricity that is produced by CHP (combined heat and power) units with back-pressure steam turbines and fed into the electricity grid equals the turbine’s gross electricity production minus its own electricity demand caused mainly by the circulating pumps of the district heating system. The process of heat transport has direct impact on the efficiency of power generation. The objective of the project is to provide the owners of CHP units with steam turbines with an optimisation algorithm as a tool to maximise the net electricity generation of the CHP unit.
Free of labour fully automatic filters for dewatering sludge from flue gas scrubbing
James Babbé
For separating solids from sludge in power plants usually conventional recessed filter presses are used. This equipment is very reliable and produces a puncture resistant filter cake with a relative high dry solid content. Due to the action principle, discharging the filter cake by an operator is required every few hours which leads to considerable costs. With the fully automatic AF series filter the basic technology of the chamber filter press is in cooperated and the filter cake discharge is completely automated and does not require the presence of an operator. A key factor here is the operational safety and reliability in harsh everyday environment, offering lowest cost per cubic meter of sludge to be dewatered.
Possibilities and disadvantages of bromide addition to reduce mercury emission at coal-fired power plants
Henk te Winkel
Mercury emissions are a global environmental issue. The contribution of Europe including Russia to global mercury emissions amounts to less than 15 %; the total contribution of EU-27 member states is about 5 %. The contribution of EU-27 power plants to global mercury emissions is estimated to be less than 2 %. The addition of bromide to fuel or brominated activated carbon to flue gas treatment is an emerging technique for additional capture of mercury from the flue gas of coal-fired power plants. The study described in this report focuses on several aspects of bromide addition to the fuel for mercury emission reduction.
The influence of film forming amines on the exchange behaviour of the condensate polishing resins
Jo Savelkoul, Frank Oesterholt, Roy van Lier and Wolfgang Hater
Film forming amines constitute an alternative treatment option for steam generators. One concern, however, is that film forming amines might adversely affect the functionality of the ion exchange resins in a condensate polishing unit (CPU). An industrial research project was carried out in order to investigate the interaction between film forming amines and ion exchange resins. Test results with a used cation exchange resin from the CPU of an industrial steam system treated with film forming amines for more than six years showed no significant effect of the employed amines on the resin exchange capacity under practical plant conditions.
Practical conversion industrial safety act, operational safety order with look at the maintenance
Gerhard Maxein and Olaf Baumann
Employers are required by safety legislation to ensure a suitable organisation and equipment to protect and improve safety and health of employees according to the state of the art. Companies operating equipment that need licensing and permits even have to cope with additional organisational obligations. Regular checks and examinations are to be made in order to verify that operational regulations meet these obligations.
Mental stress in the energy sector
Thomas Leuschner
The issue of mental stress is also gaining in importance in the energy business. The topic has to be put on the agenda in order to maintain or even increase the effectiveness and motivation of staff. A clear analysis of the current situation will follow additional measures to improve the mental capacity of personnel. A clear analysis of the current situation will follow additional measures to improve the mental capacity of personnel.