Flexibility Estimation for Wastewater Pumping Stations Participating in Grid Ancillary Services

With the increased penetration of renewable energy sources, the power grid moves towards more distributed and uncertain power generation. In order to cost-effectively counter-balance the renewables' variability, demand side response has emerged as an attractive candidate technology over the recent years. Moreover, with Internet of Things (IoT) infrastructure implemented, demand side response can be controlled over the internet. Demand side response then offers an opportunity to use these connected assets to improve the stability of the power grid in return for payments from the grid operator. As a specific example of the demand response, this paper demonstrates how wastewater pumping stations with storage tanks can be used to provide ancillary services. The technical requirements that assets need to fulfill in order to participate in the frequency containment reserve (FCR-D) services are first described. The ancillary service is then explained and evaluated which technical aspects are the most relevant and challenging for wastewater pump stations. Moreover, an approach to calculate the flexible energy and power available at the pumping station is proposed for a real-world station in Bornholm Island, Denmark.