Ancillary services for the European grid with high shares of wind and solar power

With significantly increasing share of variable renewable power generation like wind and solar PV, the need in the power system for ancillary services supporting the network frequency, voltage, etc. changes. Turning this issue around, market opportunities will emerge for wind and solar PV technology to deliver such grid services. In the European power system, adequate market mechanisms need to be developed to ensure that there will be an efficient trading of these services. For that purpose a range of (economic) characteristics of wind (and solar) power as providers of grid services need to be better understood. This relates both to the technical capabilities of the plants for delivering specific services and to the quantification of the needs. The paper presents the approach of the European IEE project REserviceS, aiming at establishing reference guidance for the ongoing developments in Europe of network codes and electricity market design. Economic insights gained from REserviceS will be shaped into recommendations to be used when establishing electricity market mechanisms and Network Codes at EU level. The project approach presented in the paper consists of two main parts namely (1) conceptually analyzing system needs for ancillary services and at assessing the technical aspects of and cost of delivering these services by solar PV and wind power, in scenarios of high renewable penetration. (2) Investigation of the need for ancillary services in typical transmission and distribution networks, and the cost and options to deliver these services at high penetration. The paper will give an overview of case studies envisaged, together with the intended methods used for the analysis. The paper also gives some initial project results. It presents the outcome of the assessment of ancillary services that are especially relevant for wind and solar power. These are mainly related to frequency, voltage control and restoration of the system. In addition, based on existing experience and wind integration studies, the paper analyses impacts that high amounts of wind/solar will have on different ancillary services required by the power system.