The potential for Micro-CHP to provide load-frequency control

To increase cogeneration of heat and power (CHP) in Germany, the enhancement of the quote of micro-CHP in residential buildings is a promising option. The authors have explored the potential for cross-linked micro-CHP systems in the distribution of reserve power to achieve load-frequency control. This paper presents the fundamental elements of a test rig validated and calibrated simulation, as well as the framework conditions for micro-CHP operation in Germany. A brief analysis of the German loadfrequency control market has shown the technical and organisational parameters and prices. The technical potential, with regard to the current contractual requirements for tertiary control has also been determined. A methodology, which leads to the calculation of the dynamic potential and the resulting completion ratio is presented. Thereby, the effects on the technical potential by changing the technical and organisational parameters have been analysed. The potential for a network of micro-CHP systems, replacing conventional power plants in providing loadfrequency control, has been determined. INTRODUCTION A promising option for a better integration of microCHP into the existing power system is the concept of so-called `virtual power plant`. This may be achieved by connecting a multitude of small power units so that they may be controlled in a similar way like large power plants. The Research Institute for Energy Economy (FfE) has examined the potential for crosslinked micro-CHP for the distribution of Reserve Energy for load-frequency control, as a key concept in the research of Network `Power Plants for the 21 Century (KW21)` [1]. The load-frequency control power is used to maintain a frequency of 50 Hz. The current technical and economic potential of microCHP to provide load-frequency control power is demonstrated using the example of the SenerTec “Dachs” module, which has an electric output of 5.5 kWel. The possibilities for enhancing the potential by modifying the storage or the design parameters are discussed. Furthermore, the authors show the potential of micro-CHP to substitute conventional power plants in the market to provide secondary and tertiary control power. CHP in Germany CHP systems utilise the waste heat from fuel combustion for heating and hence increase the overall efficiency of the power stations up to 80 to 90 percent. The German government has set a 25 percent target for CHP power generation by 2020 [2], which would mean a doubling from the current 12 percent level [3]. As Figure 1 shows the share of CHP in the German energy market is close to average, compared to other EU states. The graph also shows that the majority of CHP generated power comes from public supply. 0 5 10 15 20 25 30 35 40 45 50 55 De nm ark Ne the rla nd s Fin lan d Lu xe nb erg Ge rm an y EU -15 Au str ia Po rtu ga l Sp ain Ita ly