UC-DE-1

1. Description of the Use Case

1.1. Name of the Use Case

1.2. Version Management

1.3. Scope and Objectives of Use Case

1.4. Narrative of Use Case

Short description

The use case “Islanding” of an energy community aims to balance generation and demand of a local energy community in such a way that the load flow across the connecting MV/LV transformer is reduced to a minimum. The balancing is enabled by an energy management systems called Avacon Local Flex Controller (ALF-C). The ALF-C monitors the power flow across the transformer and controls a battery energy storage system (BESS) connected directly to the LV-terminal of the substation. Generated energy surplus will be stored in the BESS and released at times of a generation deficit. Private households equipped with batteries and controllable electric heaters can be dispatched to increase the degree of self-sufficiency further.

Complete description

The Clean Energy for all Europeans Package, encourages private households are not only to generate and consume energy, to market the flexibility of controllable producers and consumers in the future, but also to make energy available to each other and to share self-generated energy. In the future energy distribution network, the new regulatory framework, technical development and grid fee mechanisms can motivate households to found and/or join energy communities with the aim to maximize the consumption of locally generated energy. This will lead to a change in the behaviors of electrical energy exchange along the grid connection point of the MV/LV grid and consequently load flows along the MV-lines. A local Energy Management System (EMS) named (Avacon Local Flex Controller –( ALF-C) will monitor local generation, demand and storage capacities and control available flexibilities in such a way that consumption of locally generated energy will be maximized. When local generation exceeds local demand, surplus energy will automatically be stored in local storages and the consumption of available flexible loads will be increased. When local consumption is exceeding local generation, stored electrical energy in local batteries will be discharged. The target is to minimize the load flow exchange at the MV/LV grid connection to a level at which the community is virtually islanded. In cases where generation and demand can not be balanced due to a lack of available storage capacity or flexibility, the residual load will exported/imported. A sensor located at the grid connection will measure the power exchange of all 3 phases between the medium voltage and low voltage grid. The measured values indicate the residual demand or export of surplus of generated energy/power. Data is provided to the EMS an based on the information increases or decreases the load in order balance the grid. Additionally, customer households provide flexible load and storage capacities for steering. Flexible assets in the field are equipped with sensors and controllers for steering to increase or decrease demand and to command charging or discharging of local large Battery Energy Storage System and private customer household storages. Vendors of flexible assets provide a cloud data management platform from which measurement data are accessible for EMS via an backend. The interface also provides data to sensors located in private customer households will provide measurements of energy consumption and provide the necessary data for EMS to estimate the state of charge of batteries or flexible loads and potential available storage capacity. With Hhistorical measurement data and weather forecasts provided by external service providers enable the EMS to predict energy generation and consumption to maximize self-sufficiency. Controllers Actuators enable EMSC to switch on and off, increase or decrease energy consumption of individual loads, such as storage heaters and heat pumps, and storages located in private households and the large scale storage located in the community. The communication between sensors, actuators controllers and EMSC will be web based, via LTE or DSL and open protocols. Customers shall not sacrifice comfort due to a decrease of room heating. The operation of the community in an “Island” mode will be initiated by the operator.

1.5. Key Performance Indicatiors (KPI)

1.6. Use case conditions

1.7. Further information to the use case for classification/mapping

1.8. General remarks

2. Diagrams of Use Case

3. Technical Details

3.1. Actors

3.2. References

4. Step by Step Analysis of Use Case

4.1. Overview of Scenarios

Notes

This part describes the possible scenarios of the use case. The scenarios should comply with the sequence diagrams in Sect. 2 of the template, so that every step describes one part of a communication or action. Apart from a normal success scenario, different failure scenarios or alternatives can be included to describe situations where preconditions are not satisfied or unwanted states are attained.

• Primary Actor - the first actor appearing in the scenario at the incident causing the scenario to begin.

• Triggering Event - the incident causing the scenario to begin.

• Pre-Condition - indicates which terms have to be fulfilled for the scenario to be executed.

• Post-Condition - indicates which terms should be valid after the scenario. TIt can also specify whether a scenario has been successfully completed or not.

4.2. Steps – Scenarios

Scenario Name: No. 1 - (Local generation exceeds local consumption)

Scenario Name: No. 2 - (Local consumption exceeds local generation)

5. Information Exchanged

6. Requirements (optional)

7. Common Terms and Definitions

8. Custom Information (optional)