Development of a standardised assessment methodology relating to flexibility analysis for demand response

Power and energy flexibility in buildings and sites is an integral part of the solution to address the electrical grid’s challenges posed by increasing renewable generation, decarbonisation of the electricity supply and electrification of buildings, transport and industry. Addressing these challenges requires flexibility to deliver demand response services. Commercial buildings, residential buildings and smaller industrial sites have significant underutilised potential due to a lack of consistency associated with assessing their flexibility. To unlock this potential, a scalable, easy to use flexibility assessment methodology is required. A standardised four-step flexibility assessment methodology was developed during the course of this research, conducted under the scope of the International Energy Agency’s Energy in Buildings and Communities Annex 67 ‘Energy Flexible Buildings’. The four steps in the methodology consist of Step 1: Systems, Loads, Storage & Generation Identification; Step 2: Flexibility Characterisation; Step 3: Scenario Modelling and Step 4: Key Performance Indicators (KPI) Label. Underpinned by adapted elements of the energy auditing standard ISO 50002, the methodology evaluates the available electrical load reduction or increase that a building or site can provide in response to a demand response signal from an aggregator or grid operator. Addressing the need for an early stage flexibility assessment, i.e. before any investment on site and before contracts are negotiated, it explicitly includes flexibility source selection by utilising Shedability, Controllability and Acceptability as a filter or triage step. Detailed parameter definition ensures key performance elements are captured. The output of the methodology is a defined flexibility range which enables contract negotiation between building or site operators and aggregators for demand side services, captured on a KPI label for the building or site. Implementation is in an off-line manner, without the need for real-time data acquisition, ICT platforms or additional installations, as existing assessment approaches would require. Stakeholders consulted during the development of the methodology found it relevant and technically robust, particularly the incorporation of ISO 50002. A detailed case study for one building, conducted by the author, is described and verified through on-site experiments, establishing the feasibility and accuracy of the methodology. Ease of use and scalability was demonstrated through implementation by others at multiple pilot sites in the context of the Horizon 2020 Energy Local Storage Advanced system (ELSA: 2015 - 2018) project. The pilot sites consisted of different building and site types across Europe, with a number of flexible sources. Benchmarking the results against published demonstration studies showed that three of the pilot sites achieved above average flexibility. Comparing the methodology outputs with experimental results, flexibility prediction was within a 10% error range, an accepted threshold for grid prediction error in the literature, for four out of the five pilot sites.