The EcoGrid EU project actually demonstrates how the integration of Demand Side Management (DSM) into TSO operations as well as ancillary services provided by DER can be performed through flexible demand and appropriate market mechanisms. It also provides demonstration of the participation of distributed energy resources (DER) into power markets .
The concept will remove the barriers that DERs have previously been facing to enter the present market structure, e.g. requirements on size and online monitoring, and a significant administrative burden (operational rules) including bidding in the markets, complying with schedules, and financial obligations. Likewise, the market tool will provide a transparent and simple mechanism as well as enough incentives to encourage the participation of small end-consumers into power markets.
The general concept in the EcoGrid EU project is based on a real-time market approach that lets DER and flexible electricity demand receive and react on variable electricity prices. The concept provides a market-based platform and communication infrastructure that extends the current electricity market to a shorter time horizon and to smaller assets. This concept constitutes an efficient supplement to the existing electricity markets and system operation tools, facilitating further renewable energy integration in the electric power system as well as taking advantage of the demand response of end-use customers. An overview of the concept architecture is shown in Figure 1.
Figure 1. EcoGrid EU concept architecture
The real-time price is set by the Real-Time Market Operator (RTMO), which might be the TSO, on the basis of the need for up- or down regulation due to occurring imbalance between production and consumption and/or network congestions in the transmission/distribution system. If no imbalance exists, the real-time price will be equal to the day-ahead price. The continuous adjustment of the real-time price is related to the predicted price elasticity of the involved market participants.
The price is updated frequently, every 5 minutes, to utilise the potential for a dynamic response. The prices are thereby not determined by the intersection of supply and demand curves, expressed by bids, and consequently, there is no need for the market participants to submit bids.
As shown in see Figure 2, this real-time market overlaps/ complements on the one hand the balancing mechanism, which mainly is addressing larger units (several MW), and on the other hand the automatically controlled reserves: Frequency Containment Reserve (FCR) and Automatic Frequency Restoration Reserve (FRRa). In the Nordic system, the balancing mechanism (called the “regulating power market”) is constituted by a common merit order list for up and down regulation available for the four national TSOs. The list includes bids from producers, large consumers and small load aggregation, and the TSOs accept bids from the list continuously to keep the system balanced. The contribution from the real-time market demonstrated in this project will become an additional source of regulation capacity for the TSOs in parallel with the regulating power market. Consequently, the transmitted prices must be set in close coordination with the price development on the regulating power market.
Figure 2. The EcoGrid EU market concept and the existing markets
The update interval of 5 minutes provides a good compromise between on the one hand, a fast response for balancing purposes, and on the other hand the computational burden and complexity in the settlement process. However, it requires that the meters and the Meter Data Management System (MDMS) can handle 5-minute interval readings. If this is not considered feasible in a particular replication scenario, the fundamental concept and the infrastructure works equally well with longer intervals, e.g. 15 minutes or 1 hour, though clearly the dynamic response for balancing will be limited by the interval length. Therefore, the concept has a high replication potential in areas where e.g. smart meters with 15-minute/hourly readings have already been deployed, and the concept can thereby be adapted to utilise such existing infrastructure.
The EcoGrid EU market concept is tested on Bornholm, where approximately 2,000 households participate in the demonstration. Demand response to real-time price can be realised in several different ways – with and without help from automatic control systems and in-home Energy Management Systems (EMS). Four test groups will test different solutions to realise the demand response to real-time prices:
- The Manual control group (500 residential consumers)
- The Automatic control group with IBM/GreenWave home automation system (700 residential consumers)
- The Automatic control group with Siemens/SyncoLiving home automation system (500 residential consumers)
- The Smart business group with Siemens automation systems (up to 100 companies).
The Manual control group only has access to real-time price information, i.e. none of their electric household devices are automatically controlled. The manual control group will only receive manual response assistance, e.g. through training/energy advice and a feedback system with consumption and price information (see type A in Figure 3).
The Automatic control groups and the Smart business group will beside manual assistance also receive technical assistance. All of the automated households will have home automation equipment installed to optimize the operation of their electric heating, heat pumps, or similar large appliances.
Figure 3. Four different ways to implement real-time price response.
The different technical solutions are used to test the demand response variants of real-time balancing of the power system. Type A responds to one-way price signals by manual control of individual devices/resources. Type B responds to one-way real-time prices by automatic control of individual devices/resources. Type C and D use automatic aggregated control of a portfolio of devices/resources. Two main approaches are used to realise the demand response of the automated test participants:
- Automatic control of individual electric devices/resources (see type B in Figure 3)
- Aggregated control of a portfolio of electric devices/resources (see type C and D in Figure 3).
The EcoGrid project has been initiated by Energinet.dk and is coordinated by Sintef. In total, 15 partners from 9 countries are involved:
- SINTEF (Coordinator), Norway
- Energinet.dk, Denmark (TSO)
- Østkraft, Denmark (DSO)
- DTU-CET, Denmark
- Siemens, Denmark/Germany/Switzerland
- IBM, Denmark/Switzerland
- ECN, Netherlands
- Elia, Belgium (TSO)
- Tecnalia, Spain
- AIT, Austria
- TNO, Netherlands
- Eandis, Belgium (DSO)
- EDPD, Portugal (DSO)
- Tallinn University Technology, Estonia
- Landis+Gyr, Denmark
For more information, please visit http://www.eu-ecogrid.net/.