Flexibility in the energy system
Wind- and solar-based variable power generation is growing worldwide. System flexibility in the energy system – guaranteed by the following four options – is required in order to optimally integrate these energy sources:
Dispatchable generation
Storage-e and sector coupling
Grids
Demand-side integration
Digital technologies and corresponding IT infrastructure ensure networking and thus the best possible use of the four flexibility options mentioned above. Dispatchable generation is currently the most important flexibility option in the energy system.
Dispatchable generation as vital component
Dispatchable thermal power plants and pumped storage power plants are used as generation plants in flexible operation. Flexibility refers to the speed and extent to which these plants can adapt their load to the difference between current demand and feed-in of variable renewable sources. From the technical point of view, flexibility of generation plants comprises three different dimensions:
- Low minimum load
represents the lowest load level at which the plant can be operated stably and without any supporting fuels such as oil. - Short start-up time
is the period of time required from starting power plant operation up to achieving stable minimum load. - High load ramps
indicate how quickly a plants´ output can be changed within a certain period of time.
Flexibility parameters of dispatchable generation plants
Dispatchable generation plants have the following flexibility parameters:
- load gradient in load range indicated,
- minimum load and
- ramp-up time for warm and cold start-up.
The three values shown are: usual value / state of the art / future potential.
Example: The average load gradient of a hard coal-fired plants amounts to 2%/min, the state of the art is 4%/min and the future potential will be 6%/min.
** Limited by minimal load for steam turbine. CCGT = Combined Cycle Gas Turbine
Thermal power plants
Publications
Flexibility Toolbox
The Flexibility Toolbox supports operators of coal-fired power plants in switching from base-load to flexible operation. It contains information on technologies, further training courses and management topics. The Toolbox offers 40 different measures to increase flexibility through retrofits or technical interventions. The measures concentrate on combustion, water-steam cycle, turbine, control technology and auxiliary systems.
The recipe book for the flexibilization of coal fired power plants
This book presents best practices and operating procedures for the flexible operation of coal fired power plants In India. It is based on the review of published international literature, inputs from pilot studies carried out in the Indian power stations (including the test run activities under the auspices of the Indo-German Energy Forum with VGB involvement) and experts’ interviews. It was compiled by Mr. Anjan Sinha, a highly acknowledged Indian expert on this subject who had worked for NTPC for many years. The book was published in October 2020.
Partner steam power plant
The research project “Partner steam power plant for regenerative power generation” investigated how existing power plants can better regulate variable renewable generation in order to facilitate demand-oriented integration of renewables.
In the „FLEXI-TES: Making power plants more flexible through thermal energy storage“ project, it will then be investigated how to further improve flexibility of hard coal-fired plants by storing thermal energy in the plant.
vgbe-Standards
Some vgbe/VGB Standards provide important information and recommendations for action, especially for flexible power plant operation:
- Water, Boiler Water and Steam Quality for Power Plants/Industrial Plants
VGB-S-010-T-00;2011-12.EN - Condition Monitoring and inspection of components of steam boiler plants, pressure vessel installations and high-pressure water and steam pipes
VGB-S-506-R-00;2012-03.EN - Preservation of Power Plants
VGB-S-116-00-2016-04-DE - Preservation of Steam and Gas Turbo-Generator Sets
VGB-S-036-00-2017-04-DE
Article from the vgbe energy journal (formerly: VGB PowerTech Journal)
- Ke, Z., Lin, L., Schröder, H.-C. and Guoqing, F.
Plasma ignition system for oil free power plant Zetes in Turkey and its advantages fort the changed circumstance of energy market
VGB PowerTech Journal, 7/2017 - Bentsch, G.
Flexibility by individual boiler optimisation
VGB PowerTech Journal, 9/2016 - Heimann, G.
Successful erection and commissioning of a dry lignite firing system with plasma-induced ignition
VGB PowerTech Journal, 7/2016 - Michels, B. and Kotzan, H.
Retrofit of an ECO bypass to reduce minimum load of a 750 MW hard coal-fired power plant
VGB PowerTech Journal, 4/2015 - Heinzel, T.; Meiser, A.; Stamatelopoulos, G.-N. and Buck, P.
Implementation of Single Coal Mill Operation in the Power Plant Bexbach and Heilbronn Unit 7
VGB PowerTech Journal 11/2012
- Garmatter, H., Marks, E., Kostenko, Y., Veltmann, D. and Scharf, R.
Simulation of hot standby mode for flexible steam turbine operation in combined cycle power plants
VGB PowerTech Journal, 10/2019 - Abel Günther, K. and Scharfetter, C.
The industrial steam turbine as an actuator in the future energy grid
VGB PowerTech Journal, 12/2018 - Günther, K. A. and Scharfetter, C.
The industrial steam turbine as an actuator in the future energy grid
VGB PowerTech Journal, 12/2018 - Schwarz, K.
Schwarz, K. HL-class gas turbines – The next level for efficiency and flexibility
VGB PowerTech Journal, 8/2018 - Heddoun, H.and Richard, J.-M.
Last stage blade trailing edge erosion feedback in EDF LP turbines with flexible operation
VGB PowerTech Journal, 3/2017 - Rediess, M. et.al
Taken measures and experiences to ensure flexible operation of steam turbogenerators
VGB PowerTech Journal, 3/2017 - Biesinger, F. et.al
Steam turbines subject to flexible operation
VGB PowerTech Journal, 11/2016
- Weidner, J. R.
Improved condition monitoring and diagnostics for turbine generators operating at flexible grids with high amount of renewable energy
VGB PowerTech Journal, 12/2016 - Baca, M., Joswig, A.
Extended requirements on turbo-generators due to changed operational regimes
VGB PowerTech Journal, 6/2016 - Wittner, S. et al.
Impact of the new and more flexible grid code requirements on future operational behaviour of turbine generators
VGB PowerTech Journal, 8/2015
- Komogowski, L., Faust, E., Beer, S., Hummel, D., Behrens, D., Riedl, K., Wolf, G. and Deepak Prabhu, S.
Metal based latent heat storages to flexibilize industrial cogeneration plants
VGB PowerTech Journal, 11/2019 - Kahlert, S., Spliethoff, H., Behnke, C., Heß, R., Hönings, N. and Busch, C.
Flexibility of industrila CHP plants – Analysis of future operation regimes
VGB PowerTech Journal, 10/2019 - Hoppe, T., Braune, J. and Nielsen, L.
Dynamic System Simulation for New Energy Markets – Optimization of a Coal Fired Power Plant Start-up Procedure
VGB PowerTech Journal, 9/2019 - Herzig, M., Pago, B.-C., Neumann, C. and Paetzold, J.
Simulation of the behaviour of real power generation plants in relation to fast frequency changes (RoCoF) according to the requirements of the current VDE-AR-N 4120:2018
VGB PowerTech Journal, 6/2019 - Loeper, T., Krüger, M., Richter, M., Klasing, F., Knödler, P. and Mielke, C.
Potentials of thermal energy storages integrated into steam power plants
VGB PowerTech Journal, 4/2019 - Löhning, G., Wenzel, F., Haake, D. and Mehlow, F.
Innovative system service: extended island operation capability using thermal power plants
VGB PowerTech Journal, 4/2019 - Dinkel, K. and Peterseim, J.
Battery augmented biomass and waste power plants – A new approach to provide grid services
VGB PowerTech Journal, 1-2/2019 - Katzer, C.
Need for combustion research for lignite-fired power plants – example of BTU Cottbus – Senftenberg‘s chair Kraftwerkstechnik
VGB PowerTech Journal, 8/2018 - Moxham, B.
Converting coal to biomass: Making the energy transition feasible
VGB PowerTech Journal, 6/2018 - Lehmkuhl, C. and Klag, O.
Flexible operation of power stations requires innovative materials and test methods
VGB PowerTech Journal, 6/2018 - Bolhar-Nordenkampf, M., Kokko, A. and Kinni, J.
Multifuel CFB solutions – Producing power in a flexible environment
VGB PowerTech Journal, 4/2018 - Alwers, A. and Fuchs, U.
Instant performance at the push of a button – Boost the opportunities of your plant with hybrid solutions
VGB PowerTech Journal, 12/2017 - Leithner, R. and Brinkmeier, N. O.
Flexible power plants – Economic low load and house load operation with coal
VGB PowerTech Journal, 12/2017 - Picard, S. and Aschoff, T.
512 MW in 10 minutes – New York City peaking plant solution applicable for Europe
VGB PowerTech Journal, 7/2017 - Loschen, R.
With flexibility to more climate protection – Energy management in the Marl Chemical Park
VGB PowerTech Journal, 1-2/2017 - Brüggemann, H., Kluger, F. and Schmidt, G.
Innovative concepts for flexibilisation of power plant operation
VGB PowerTech Journal, 4/2017 - Hönings, N.
The new high-flexible Chemiepark Marl power plant
VGB PowerTech Journal, 10/2016 - Kahlert, S., Spliethoff, H., Behnke, C., Heß, R., Hönings, N. and Busch, C.
Flexibility of industrila CHP plants – Analysis of future operation regimes
VGB PowerTech Journal, 8/2016 - Lens, H. and M. Nolte, M.
Reduction of the minimum generator power output of hard coal-fired power plants through control and process engineering
VGB PowerTech Journal 4/2015 - Heimann, G.
Increasing flexibility of lignite-fired power plants
VGB PowerTech 4/2015
Pumped Storage Power Plants
Hydro power makes a central contribution
to flexibilise the energy system
Hydropower | Part of the Renewable Family
Europe’s hydropower industry is a world leader in offering sustainable development and innovation for the environmental friendly generation of energy. The power of technology and innovation is important for pushing big ideas, making the low carbon shift, creating new industries and jobs and more importantly,. in the service of people, our future generations and the planet.
Eurelectric-vgbe Hydropower - Fact sheets
Hydropower plays a major role in meeting Europe’s ambitious energy transition goals. In particular, it complements the increasing share of variable renewables in the European power system. Such a system, with large deployments of wind and solar, requires sufficient flexibility, firm capacity and the ability to balance variable generation. Hydropower has all these capabilities.
Article from the vgbe energy journal (formerly: VGB PowerTech Journal)
- Bauhofer, P. and Zoglauer, M.
Pumped hydro storage as enabler of energy transition
VGB PowerTech Journal, 11/2019 - Wolfgang Stroppa
TIWAG-Tiroler Wasserkraft AG reconstruction and new construction projects for the energy turnaround
VGB PowerTech Journal, 4/2016 - Peter Matt
The Obervermuntwerk II pumped hydro storage plant and its flexibility
VGB PowerTech Journal, 3/2016
vgbe on the way to the energy system of the future
vgbe White Paper Energy System
In its White Paper “Being Part of the Future Energy System”, vgbe presents eight strategic fields of action enabling the implementation of sustainable, environmentally friendly, economic and secure energy supply. All players in the energy sector – from politics, business and society – are called upon to make their contributions to the implementation of these fields of action.
International activities
vgbe participates in the Advanced-Power-System-Flexibility(PSF)-Kampagne, which is coordinated by the International Energy Agency (IEA) and which is a continuation of the Advanced-Power-Plant-Flexibility-Kampagne, concluded at the ninth Clean Energy Ministerial (CEM9) in Copenhagen. CEM is a global platform, comprising 24 countries and the European Union, to promote sustainable and clean energy supply.
Flexible coal-fired power plants are an important focus of the Indo-German Energy Forum (DIEF). The DIEF is a format for the exchange between the Indian and German Governments on issues of energy policy. vgbe is cooperating in the Task Force Flexibility, which coordinates all activities around flexible operation of thermal power plants with the focus on two reference power plants at the Dadri and Simhadri sites. vgbe cooperates with its Indian partner the Excellence Enhancement Centre (EEC).
vgbe is cooperating in a Research and Innovation Agenda & Technology Roadmap for hydropower within the scope of the EU Horizon 2020 programme. In HYDROPOWER EUROPE the issue of flexibilisation also plays an important role.
Get in touch
We are looking forward to inform you
Our team
Dr. Claudia Weise
International Projects
Dr Mario Bachhiesl
Head of Renewables and Distributed Generation, Health and Safety