Ökoeffizienz von Flexibilisierungsmaßnahmen in Energieversorgungsnetzen unter Berücksichtigung der Integration von Windenergie

  • Eco-efficiency of flexibility measures applied to energy supply systems having regard to wind energy integration

Macharey, Uwe; Schnettler, Armin (Thesis advisor)

Aachen : Publikationsserver der RWTH Aachen University (2009)
Dissertation / PhD Thesis

Aachen, Techn. Hochsch., Diss., 2009


This dissertation deals with the development of a method to assess the eco-efficiency of flexibility measures applied to the electrical energy supply system. As the regional wind energy feed in exceeds the regional power consumption temporarily even to a high extent, leading to an export of surplus wind power from local grids to the transmission grid and by this to distant areas, and as neither the existing distribution grids nor the transmission grids were set up for today’s requirements, the application of flexibility measures becomes vital. The required grid extension cannot keep pace with the growing share of wind energy feed in, which results in bottlenecks. Thus, other technical options to increase dynamic system operation come into focus as well, even though there remains uncertainty, if they can be an alternative to grid extension or if they merely represent an interim solution. Former investigations concerning the assessment of alternative transmission technologies were limited on the comparison of investment costs or environmental impacts against the background of transmission capability. With this dissertation, an abstract method for assessing the eco-efficiency of flexibility measures in power systems is being developed. Therefore, well known practices of ecological and economical assessment are optimised regarding technical backgrounds as well to offer an objective and abstract comparison of the different measures. In doing so, it is emphasised, that only a direct assessment of CO2-emissions is necessary for ecological assessment. The investigation of other ecological impacts is part of the project specific approval procedure and will be respected as a sensitivity by varying the realisation time of the measures. Regarding monetary aspect, it will be shown, that solely costs have to be assessed, which are generated in the balance room by realising a specific measure. The application of the assessment method will be shown for a representative model of a 110 kV network area considering the implementation of overhead line temperature monitoring, the utilisation of a high temperature overhead line conductor (ACCR) and the network extension by realising a new corridor with TACSR high temperature overhead line conductors. It becomes clear that the eco-efficiency is significantly influ-enced by the possible wind energy feed in and by covering consumer loads. Investments show relatively low impacts on the results. To support the objectivity of the given comparison, a sensitivity analysis is obtained for the categories global power-mix, compensation of omitted incomes of wind energy converters, enhancement of generation management, period under observation and realisation time. Against this background, the results of the exemplary investigations for three assessed locations (strong wind, medium wind, low wind) show the highest eco-efficiency for the grid extension.