Abstracts - VGB PowerTech Journal 10/2005

Feasibility of Geothermal Power Generation in the German Upper Rhine Graben

Wolfram Münch, Hans Peter Sistenich, Christian Bücker and Thorsten Blanke

A consortium of EnBW, RWE Power and RWE Dea has carried out a feasibility study to evaluate the utilisation of geothermal heat for power production in the Upper Rhine Graben in southern Germany. Geothermal power production has being supported through the German Renewable Electricity Act (EEG) since its 2004 amendment. The study includes the aspects drilling and production engineering, power plant technology as well as the economics of a low temperature geothermal power plant. As one result, the study indicates clear preferential areas for possible geothermal projects in this region. However, the geological conditions that have been determined yet are by far not sufficient to develop a systematic geothermal power plant, not even under the favourable conditions of the EEG support. With an optimistic view regarding the geological conditions, the production cost turn out to be about 30 Euro-cents per kWh, which is twice as much as the tariff granted through the EEG.

Initiatives for Ensuring Balanced Technology Options

Franz Bauer, Karl. A. Theis and Hans-Joachim Meier

Sufficient experience has been gained through liberalisation of the electricity market and competition. The market with specific topics is well established. The regulatory impact is characterised by a set of measures aiming at increased application of renewables as well as increasing energy efficiency. The power plant park in Germany and in the European Union has to be renewed in the next years requiring an investment volume of more than 40 respective 200 bn. Such a programme needs technologies and primary resources of energy.

Condition Monitoring – An Approach to Operating Safety

Hermann Farwick, Franz Bauer und Günter Gilberg

In the operation regulations order among others, a procedure is laid down for the performance of periodic testing, in particular internal testing. Essential focus of the project “condition monitoring” is to develop a procedure for periodic testing which is orientated on the condition of a component including appropriated measures and their effectiveness.
Technical content is the suitability and compatibility of these measures which can be derived out of the condition of the component. At the end a VGB Guideline will be published. Basis of this approach is a consequent analysis of the operational experiences. Exemplarily all internal periodic tests of three units have been analysed over a period of 15 to 30 years. These investigations showed that a clear majority of systems has not suffered from any damage. Furthermore in one damage case the root cause could be identified. By means of evaluating the operational experience the basis was laid for the new concept defining the measures for periodic testing. This means in which periods of time a system has to be tested according to the system condition. In order to broaden the basis for this VGB Guideline to be established, an extension of the analysis of operational experience is planned. This guideline has to be congruent with the regulations of the TRBS which will be worked out as official regulations concerning operational safety.

Recent Developments Regarding the Regulations for Utilisation of Fly Ash in Concrete

Udo Wiens

From January 1st, 2005, planning permission can only be granted for concrete structures designed according to DIN 1045:2001-07 and DIN EN 206 1:2001-07. This means that all sectors of the economy and of industry involved in concrete construction now have to apply the new standard. Since the publication of the new generation of standards in 2001, DIN 1045-2:2001-07 has been modified, and further national and European regulations with relevance for the production and application of fly ash in concrete have been published and adapted. Revision of EN 450:1995-01 “Fly ash for concrete – Definition, specifications and conformity criteria“, for example, commenced in 1999 and was completed in 2004. The final drafts of the European product standard prEN 450 1 and the associated standard for conformity evaluation, prEN 450-2, were adopted by the CEN member states at the end of last year through a formal voting procedure. The two harmonised standards will be published as DIN EN 450-1 and -2 during the first half of this year. All previous national standards will have to be withdrawn in 2006. The paper provides an overview of and commentary on the main new or modified technical regulations with relevance for the production and application of fly ash as a concrete addition since the publication of the new DIN 1045 in 2001. The changes were presented and discussed in detail at the BVK/VGB symposium that took place on 3rd March 2005 in Frankfurt.

Power Plant Operation Management – A Challenge to the Energy Market –

Bernd Lipinski, Ralf Kirsch and Gert Schletter

The tasks of power plant operation management have sustainably changed with liberalisation. For Vattenfall Europe this meant a re-organisation of the functions and responsibilities within the power plant sector.
The Vattenfall Europe Group integrated the sectors mining, power- and heat generation from fossil fuels and nuclear power as well as the operation of high-voltage-, low-voltage- and distribution networks. The Group set up itself along the value chain and formed the Business Units Generation, Transmission and Distribution of power and heat as well as the provision of the system services. Vattenfall Europe introduced a Steering model for the sections Generation, Trading and Sales which bases on the fundamental intent of optimising the business units individually to a large extent.

Impact of Power Plants with CO₂ Capture for Planning Future Production Portfolios

Markus Ewert

Capturing CO₂ during electricity production using fossil energy sources gain more and more interest at research institutes, manufacturers and energy suppliers. Especially with the European emission trading scheme European power plant operators intensify their research and development activities regarding technical possibilities capturing and storing CO₂. In this article a survey is given about the state-of-the-art procedures for CO₂ capture in coal-fired power plants and for the storage of the captured CO₂. Important parameters for investment decisions will be determined and their current uncertainties will be evaluated. Priorities for national and international research and development projects in the field of CO₂ capture and storage will be deduced from this analysis. Taking into account alternative and supplementary climate protection strategies for electricity generation (e.g. increasing the efficiency of conventional plants) scenarios including the commercial use of CO₂ capture will be developed.

The Next Generation of Hard Coal-fired Power Plants

Georg-Nikolaus Stamatelopoulos and Gerhard Weissinger

Coal as a fuel is of major importance, particularly in the German, but also in the European power generation. Security of supply, stable prices in comparison with natural gas and resources to last for several 100 years are the main advantages of this primary energy source. For the next two decades a requirement for new power stations with a capacity of approx. 40000 MW is predicted in Germany alone. These power plants to be newly installed, will replace on the one hand the existing plants, which no longer represent the state-of-the-art, and on the other hand will cover the predicted increase of power consumption. In the EU-15 countries a requirement for new power plants of approximately 200000 MW is assumed for the same period. Considering the reduction of the nuclear energy share in electric power generation it can be assumed that new power stations fired with competitive imported coal will account for a major share of the additional plant capacity. This article describes how the design of modern coal-fired power plants can meet the requirements both for high efficiencies and for flexible use. Further it describes the progress in the increase of the steam parameters as well as the contribution of modern, highly efficient hard coal-fired power plants to the reduction of CO2 emissions and the saving of resources.

AGFW-VGB Matrix “Reference Values Condensation Electricity Generation”

Michael Kranz, Ullrich Müller and Hans-Joachim Meier

The EU Directive 2004/8/EC, supporting useful heat demand orientated Cogeneration of Heat and Power (CHP) in the energy domestic market, also establishes a basis for the national promotion of CHP. Its principal aim is to increase energy efficiency. The Directive provides methods to determine the efficiency of a CHP process based on reference values. Currently a consortium, including COWI, ECN and BEI, works on the EU-wide harmonisation of reference values for separate electricity and heat production. The research is done on behalf of the EU Commission DG TREN, JRC. In preparation for establishing reference values for Germany, AGFW and VGB jointly conducted a research on reference values for condensation electricity production. The results are summarised in an AGFW-VGB matrix “Reference Value for Condensation Electricity Generation”, as shown below. Since the EU Directive only foresees the promotion of high efficient CHP, the setting of reference values has a long-term influence on the development of CHP – not only in Germany. In addition, the essay offers technical suggestions clarifying on open questions related to the implementation of the Directive.

Generation between Market, Regulatory, Framework and Environment

Klaus Pitschke

The focus in the present discussion about energy policy should be on using energy business instruments to design reliable, price worthy and environmentally compatible energy supply systems in a liberalised market. Supporting the preservation of a broad-based energy mix as well as a fair, market-based promotion of renewable energies is a prerequisite to this. Power plant operators can also make a technological contribution to climate protection. Vattenfall decided to build a CO2-free pilot power plant. Full-scale industrial use of this technology should not be expected before 2020. The energy business is related to research activities in a way that should not be underestimated. A functioning political and legal framework for the energy business is therefore among the preconditions for protection and strengthening of technological know-how locations.

Effect of High-temperature Corrosion on the Final Reheater (RH2) of the Boiler in the Neka Power Plant

Behzad Boroumandi

It is a well-known fact that boilers which use coal and fuel oil are faced with problems of high temperature corrosion. The corrosion rate of the boiler tube metal depends on many factors such as tube material, fuel gas temperature, tube metal temperature, constituents of fuel (sodium, vanadium, sulphur, etc.), excess air and the operating mode of the boilers. Although several actions can be taken to reduce the corrosion rate, e.g. employing additives, or reduction of excess air. However, this paper does not deal with the chemical aspect of corrosion. In fact based on the experiences gained from the past operating history of the boiler and extensive thickness measurements which were carried out over the past twenty years for four 1472 ton/hr sub-critical once-through boilers of the Neka power plant a maintenance policy was selected in other to avoid unplanned outage of the boiler because of tube rupture caused by thickness reduction due to high-temperature corrosion. The important finding was that although at the middle part of boiler due to higher flue gas temperature corrosion is relatively higher, heavily corroded tubes are not concentrated there; therefore, partial replacement of tubes is not technically and economically justified. It was also found that early chemical cleaning of water side and also flue gas side plays an important role in reducing metal temperature and flue gas temperature thus reducing the corrosion rate.

New Technologies – Boundaries of Insurability

Dieter Schimana

The insurance industry has always kept pace with advances in power station technology. Major development steps have been supported by an appropriate distribution of risk among developers, manufacturers, owners, investors and insurers. The main consideration is the extent to which the insurance market classifies damage to new technology as foreseeable and therefore uninsurable. In the 1990s, insurers responded to this by making the answer clear in the terms of insurance for gas turbines, for example. More recently, we have seen a similar response for wind power and biogas plants. To avoid any nasty surprises when an insured event occurs, it is essential to conduct an early and frank discussion of new developments with all parties involved in a project, including lenders and insurers. This article will use examples to demonstrate criteria for classifications in the insurance market and the impact on the insurance protection for such plants in the opinion of an industry expert who is regularly involved in such projects.