By smartgrider In DEMAND SIDE MANAGEMENT Posted 2015-05-06
– Project Ownership:
Smart Grids Model Region Salzburg is a collaboration between: AIT Austrian Institute of Technology GmbH CURE ? Center for Usability Research and Engineering Siemens AG Austria Salzburg AG Salzburg Netz GmbH Salzburg Wohnbau GmbH Vienna University of Technology Funded by: Climate and Energy Fund (KLIEN) Austrian Federal Ministry for Transport, Innovation and Technology (BMVIT)
– Electricity system in Austria: Target 2020: ? CO2 reduction: 16% ? Share of renewable energy participating in the total energy
source mix (Renewable share): 34% Total consumption: 70 TWh in 2012 Household consumption: 4,200 kWh/yr in 2012
– Electricity consumed (2013): 246 TWh
– Market structure: Austria with 8.4 million people has a liberalized market with independent network operators: 1 TSO (APG) and 128 DSO’s
– Contact: Sara Ghaemi, AIT Austrian Institute of Technology, firstname.lastname@example.org
Smart Grids Model Region Salzburg
Smart Grids Model Region Salzburg (SGMS) is a “living lab” for Austrian Smart Grid experiments. In order to prove the feasibility of technical, operational and business concepts for a Smart Grid, it is necessary to set up a field test for demonstrating and validating the functionality of the proposed concepts. The aim of the SGMS is to aggregate different Smart Grid applications in an integrated system and to implement flagship projects in the real environment considering problems of daily business and addressing specific customer needs. The projects within the framework of SGMS have started since 2004 and each project delivered essential inputs to the overall goal. The holistic approach (see Fig. 1) chosen in Salzburg is noteworthy because the system integration is done at all levels. The main focus and the core of the SGMS can be classified as following: ? Active distribution grids ? Load and demand side management ? Integration of electric vehicles (EV) ? New technologies and intelligent strategies ? Virtual power plants Among 23 conducted projects, about 6 are demand management oriented. Each pilot project has unique technical solutions and the suggested improvements have been applied in the technical solution of the follow up projects. In order to analyze the impact of various DSM programs, different projects have been carried out which range from analyzing the integration of renewables into distribution networks to assessing the impact of integration of EVs, residential consumers, buildings and commercial & industrial enterprises into the electricity grid. DSM has been pursued from various points and includes residential consumers, buildings and electric vehicles as active components for the future energy systems. Consumer2Grid (C2G), Persuasive End-User Energy Management (PEEM), Building2Grid (B2G), Vehicle2Grid interfaces & strategies (V2G), load management and “Buildings as interactive Smart Grid participants” (HiT is the German abbreviation) are the selected projects for this case study which have been marked in (Figure 1).
Objectives & Benefits
In the framework of the SGMS about 23 projects have been carried out which follow various objectives from Integration of renewable energy sources to electric vehicles, buildings and household consumers into the distribution grid. The uptake integration of different active components into the grid introduces many new challenges for the existing infrastructure such as need for more flexibility on generation as well as on the demand side, new business models for the electricity market and data security & privacy of customers The SGMS tried to find possible solutions and assess the effectiveness of approaches in different pilot projects. Since the focus of this case book is demand management, the following project objectives are highlighted here: ? Analyzing and demonstrating the impact of various feedback systems on the total energy consumption in the private sector ? Analyzing and demonstrating the potential of demand response in different energy sectors ? Analyzing and demonstrating the effect of various market and business models for the integrating of active components ? Demonstrating the application of smart metering and developing monitoring and validation concepts for the suggested approaches ? Testing the role of ICT in developing various concepts for security & privacy issues The benefits of the mentioned projects can be summarized as:
– Possibility for testing various features in the field test
– Investigation of the ability, advantages and drawbacks of centralized and decentralized feedback systems in the private sector
– Testing possible ICT solutions to transfer data locally within a building automation system and globally within the energy management system
– Understanding the required level of security and privacy in a Smart Grid through smart metering and automated metering infrastructure AMI infrastructure in order to ensure the trust of consumers
– Determine the effective triggering signal for demand response management systems and essential data for receiving the optimal response
– Assessing the potential of flexibility in energy consumption of different sectors by implementing various concepts of energy management systems
Consumer2Grid (C2G): by visualizing the energy consumption using feedback systems and engaging consumers in the household sector, they reduced their total electricity consumption by about 7% per year but the response faded over time.
PEEM – by including external information like the availability of renewable resources or grid congestion to the feedback system, the consumer responded to the received signals continuously without losing interest. Loss of comfort and habit changes were the main obstacles for consumers to participate in this system.
Building2Grid (B2G): by integrating the feedback system into the development of the building energy agent (BEA) system, the responses were automated and user independent therefore predictable for providing ancillary services like voltage and frequency control. By implementing the BEA in 10 selected buildings 350 kW were reduced during peak times.
Buildings as interactive smart grid participants (HiT): is an ongoing project which pursues assessing and optimizing the potential of a smart grid-friendly buildings and expanding the interaction between buildings and their residents. The results will be published in 2015.
Load management in commercial & industrial enterprises: the potential of demand reduction in Austria has been estimated to be around 664 MW. Cooling devices can participate in peak load reduction by 3% to 10%. Supermarket chains are one of the energy consuming sectors which can play a significant role in load management programs.
V2G strategies & V2G interfaces: by assessing business models and analyzing technical, economic and environmental consequences of integrating EV’s in low voltage networks, it was found that solely market-oriented or grid-oriented controlled charging can only partially solve congestion problems. The implementation of an adaptive controlled charging strategy is necessary to alleviate congestion problems due to charging. It may be possible to provide tertiary balancing services of about 30 MW with up to 22,000 electric vehicles in the region.
Current Status & Results
Most of the described projects (except the ongoing HiT) have been finalized and the results have been published on: “http://www.smartgridssalzburg.at” The selected projects for this casebook have been classified into consumer-, building- and electric vehicle-integrated and introduced in brief in the following: Customer integrated: The Consumer2Grid (C2G) and PEEM projects had the main focus on the integration of residential consumers into the electric power system. These projects focused on the impact of various feedback systems on the amount and pattern of electricity use. Various feedback systems (Annual billing , monthly billing, web portal, In-home display and wattson ) have been implemented in the field test of the C2G project including 288 households and have been operated for one year (Figure 2). The average reduction in electricity consumption across all test groups was about 7% with a minimum value of 2% for monthly billing feedback system and a maximum value of 11% for web portal users. However, these results are statistically not significant. Different feedback systems offer different functionalities which can impact the awareness of people about their energy consumption. For example, consumers had the possibility to compare their daily or monthly consumption in the web portal as well as in the in-home display system with previous days and months and in addition get some saving tips from the monitoring system. Analysis of the logged data shows that the consumers were more interested in daily comparisons and used suggested tips for the energy saving in the beginning of the test period and the learning phase. Consumers were very interested in questioning their own behavior in the beginning of the project but their inclination for using the information of the feedback system decreased over the course of time. Therefore, it is important to offer additional functionalities besides electricity-use feedback to residential customers in order to maintain their interest over the long term. In this regard the PEEM project has been carried out in which a new feedback method named “FORE-watch ” has been developed and implemented (Figure 3). This feedback method not only gives consumers information about their energy consumption, but also uses colours to inform two groups of users about the availability of renewable resources or the grid congestion in the next 12 hours. Prognosticated data notify the users when the “good” (green), “average” (yellow) and “bad” (red) time is for using energy. On one hand, this technology provides residential customers with the supportive information to change their consumption behaviour toward more sustainable use of electricity. On the other hand, old habits and accustomed comfort are the main barriers for consumers to alter their energy consumption pattern which could be solved by introducing automated demand response technologies in household sector.
Figure 2: Energy Feedback systems, in-Home display, Webportal and Wattson, in C2G project
Figure 3: Forewatch, developed feedback system for PEEM project / FORE stands for “Forecast Of Renewable Energy”
Building Integrated: based on the results of the aforementioned studies, it made more sense to integrate the feedback system, which provides consumption data and time of use prices, into home automation system. This allowed the responses to be independent from user behaviour in order to optimize results without the loss of customer comfort. Automated demand management helps consumers keep the requested comfort level and optimizes the use of available renewable energy sources at the same time. In this regard, the B2G project has been conducted to analyze the effect of two approaches on the energy consumption of buildings:
1) Direct load control: Easily accessible flexible loads used in this project are electric heating and the hot water systems. In the direct load control approach, these units were switched on/off by the grid operator according to predefined regulated times. The calculated theoretical potential of load shedding for “Salzburg grid” is up to 50% of peak demand when all buildings are equipped with electrical heating systems. However, practically the load shedding potential is about 10% of the peak load in parts of the grid with a high density of installed electric heatings and about 1.5% of the peak load is shiftable within the existing legal framework. Since this method does not get any feedback from the indoor/hot water temperature and does not consider the comfort of the consumers in the building, it is considered as a non-flexible solution, which is also limited to predefined hours within a day.
2) Flexible home automation system: In B2G, it has been suggested to take this process within the building automation system in order to shift flexible loads automatically considering comfort range and external parameters like the outdoor temperature. Thus a building energy agent has been developed which acts as the communication interface between the building and the electric power system and fulfills the following tasks:
– Estimates the flexibility of these components based on outdoor temperature and optimizes the time of demand shifting according to the energy price
– Forecasts the energy consumption of the thermal components in the building
– Optimizes the utilization of on-site generated energy from e.g. photovoltaic units using flexible loads (thermal loads, electric vehicles,…)
Figure 4: Approach in the Building2Grid project
The developed building energy agent was implemented in 10 selected buildings. The maximum reduction achieved by using the building energy agent system is about 350 kW across the 10 buildings. The results have been analyzed for one of these buildings consisting of 5 residential apartments. It is technically and practically possible to achieve up to 3.7 kW of flexibility for 6 hours . In one of the field tests (St. Johann in Salzburg), the load could be shifted even for 12 hours without a perceivable impact on room temperature. However, this potential depends on the outdoor temperature. The colder the outdoor temperature is, the higher the flexibility is for load shifting. In order to optimally integrate active buildings into the smart distribution grid, not only the voltage should be kept within the regulated marginal values, available renewable resources should also be optimally exploited. In this regard, the traffic-light model has been suggested in which active buildings react to the market signal as long as critical threshold values on the power grid have not been reached (green lights). When the grid gets closer to its voltage boundaries (yellow light) the market based mechanisms is optimized considering technical constraints (see Figure 4 & Figure 5). When the voltage limits are exceeded then the grid operator can act to stabilize the grid without taking the market into account. In order to implement this proposed model a realistic market concept needs to be developed which will be done in the ongoing project HiT. To this end, necessary general conditions (“market rules”) were coordinated and the required systems and the technical solutions were designed and built. The subsequent trial operation represents a foundation for acquiring further knowledge and building more complex system and market models.
Figure 5: Traffic-light model
Since the B2G project was mainly devoted to residential and small office buildings, another study analyzed the potential of load shifting for commercial and industrial buildings in Austria. In this study different sectors such as restaurants and tourism, business, healthcare, production and municipalities have been interviewed and related information has been gathered through questionnaires. According to this study, the potential of demand reduction in Austrian commercial and industrial buildings has been estimated to be around 664 MW. Cooling devices can participate in peak load reduction by 3% to 10%. Supermarket chains are one of the energy consuming sectors which can play a significant role in load management programs.
Electric Vehicle-Integrated: In the framework of SGMS, various concepts for the integration of electric vehicles in terms of interaction portals, interfaces and visualization were established and technological and economical effects of “grid-to-vehicle” and “vehicle-to-grid” concepts on the electricity grid were evaluated. These projects examined the effect of three charging strategies: uncontrolled, market-oriented and grid-oriented, in medium and low voltage grids.
The results of the project calculated that the effects of different charging strategies are more considerable in low voltage grids. In general, the uncontrolled charging approach is more favorable for grid operation since the market-oriented controlled charging causes a large number of vehicles to charge at the same time. However, uncontrolled charging leads to congestions at the low voltage level if the penetration rates reach 40% for electric vehicles, which may be the case in 2030 according to estimated scenarios. Grid congestion could be experienced earlier in parts of the network with higher load factors at the end of the feeders. In the case of market-based charging strategy, grid congestions can even occur with 25% penetration of electric vehicles.
In order to operate the current infrastructure of the electricity grid more efficiently, suitable measures such as slow charging and symmetrical distribution of charging points on a three-phase system should be considered. Otherwise, a large amount of available grid reserves will be dissipated. However, grid-oriented controlled charging can release the occupied capacity of the grid by 15% but it does not offer an optimal solution for the system as a whole. A further type of market-oriented controlled charging and discharging would allow electric vehicles to participate in the balancing market. In order to deliver a constant level of 30 MW as tertiary control power within a day, the number of required electric vehicles for two defined scenarios, charge and discharge “at home” (blue line) and “at home & work” (red line), has been presented in Figure 6. This corresponds to between 6% and 8% of total number of cars in the province of Salzburg.
Figure 6: Number of required electric vehicles for providing 30 MW balancing services
Although controlled charging can release occupied grid reserves in the short term, it is not the optimal solution. Adaptive charging (including both market and grid oriented solutions) has been suggested in order to optimize the integration of the electric vehicles into the grid.
The demo projects made clear that the estimated theoretical potential is not viable in practice. Assumptions which are considered for simulations hardly match real conditions and in some cases they are not technically applicable. In addition, the reaction of end users to the various feedback systems could not be simulated and is not forcastable. Since the results of each project have been integrated directly into follow up projects, the experiences have been used to improve the technical concept, implementation and evaluation of the results. The results and lessons learned in the field of load management were valuable inputs for the HiT project which pursues various Smart Grid applications in the context of buildings in an innovative housing community.
The objectives of the project are optimised planning, construction and operation of the block of flats in Rosa-Hoffmann-Straße, Salzburg Taxham, named “Rosa Zukunft”. The project started in January 2011 and will be finalized in May 2015. Currently, the construction of the buildings and the energy center are completed and the apartments have been occupied in September 2013.
The following results are expected from the project:
– Potential assessment of Smart Grid-friendly buildings, optimisation and developement of building technologies for the residential complex
– Description of interactions between users and the building
– Evaluation of the grid-friendliness of the building
– Creation of a roadmap for the implementation of a Smart Grid-friendly residential complex
The final report will be available at the end of the year 2015.
Lessons Learned & Best Practices
The goal of these projects is to demonstrate different aspects of the smart energy system of the future in order to figure out which of the available technologies are applicable and which new functionalities should be integrated into the system. The cooperation within the consortium made it possible to integrate different perspectives and competences. The first lesson and the motto of this flagship project is “the whole is more than the sum of its parts”. The following lessons have also been learned in the course of the projects:
– Focusing solely on providing feedback on the electricity use is only of marginal interest. In order to achieve sustainable results it is necessary to combine information and automated services.
– Consumers are not only interested in monetary benefits which should be integrated in the feedback system as time of use (TOU) or dynamic tariffs but also on altruistic motives like contribution to save the environment.
– Visualization and feedback systems motivated users only in the beginning of the projects to reduce their consumption. Including additional information like the availability of renewables or grid congestion leads to better user response.
– Additional services, which offer further benefits to residential customers, can be developed using the available data and sources. However, mechanisms to protect privacy must be taken into account from the very beginning to design effective Smart Grid information and communication technologies.
– Based on the experiences from C2G, the decentralized data transfer method is suggested for the further projects because it is in accordance with the data minimisation principle of the Data Protection Act of Austria and has lower investment cost. The data minimising approach fulfills the regulations set out in the Data Protection Act because only the data used in billing or for providing legally mandated information (depending on the model, a load profile or daily usage statistics) is transferred to the grid operator.
– The integration of the feedback system into the home automation has additional potential to offer secure solutions at local level. It keeps the control over the data “closer” to the user.
– Cost synergies may also be created when the investments are spread out over different parts of the system and are therefore easier to make.
– Automation facilitates sustained changes in households. However, it is absolutely necessary that customers have the possibility to control their devices and to be able to intervene in automated decisions in demand response programs.
– Thermal simulations show that even old buildings possess suitable characteristics which are qualified to shift heating loads over a period of several hours.
– Buildings can actively be integrated into the electricity system and have the potential of reducing peak loads up to 10% depending on the weather, time of the day and year considering the installed electrical heating systems in each building. In order to use the potential of buildings as a part of smart infrastructure, it is necessary to include outside information in the local optimization system in the building.
– Market models and market rules need to be established to guarantee security and stability of the grid while at the same time the best price on the electricity market is obtained by offering flexibility. ?There are still many open issues regarding technical details like standardised communication protocols, security of data transfer and privacy of collected data from buildings.
Commercial & Industrial:
– Load management concepts can be realised by using ICT (Information & Communication Technologies), especially in the business sector. In order to use this available potential it is necessary to adapt the legal framework.
– Technically there is considerable potential for load management in the range of Megawatts which varies according to the place, time of day and the season. This potential can only be exploited when the required bidirectional ICT infrastructure is provided. Particularly qualified components for demand management are thermal storage components such as heating system, water boiler, etc.
– Theoretically, one third of installed capacity of electricity consuming devices have the potential to act flexibly once a day for 15 to 30 minutes. This degree of potential for the province Salzburg would provide up to 200 MW of power for flexibility services. Nevertheless, practical experiences depict that only 10% of the available potential can practically be used.
– In order to be able to use the existing grid as efficiently as possible, slow charging (with the capacity of 3.5 kW) is to be preferred. Symmetrical load distribution via three-phase charging should be adopted.
– ?Purely market-oriented controlled charging, which leads to the high number of electric veicles charging at once, should be avoided. Market-, load-, and grid-oriented controlled charging should therefore be conducted with fewer cars charging at the same time in order to be able to apply aspects of the market and to use existing network infrastructure efficiently. In order to make the system as efficient as possible, a scheme for adaptive charging should be developed. Adaptive charging should be introduced as soon as the necessary functionality in the power grid is present or, as anticipated in the V2G Strategies project, when the level of controlled charging has reached the critical point at which the energy system can no longer adequately handle the integration of more electric vehicles.
– Vehicle-to-grid delivery of electricity is not feasible based on current market conditions, since the current costs exceed the achievable benefits by a factor of two.
– In order to implement three-phase charging at low loads, decision-making between the involved stakeholders (grid operator, electric vehicles charging station manufacturers, electric vehicles service providers) should be coordinated and appropriate technical and organisational regulations should be agreed.
One of the major benefits of the SGMS living lab is that it is a proper testbed for assesing the possible technical solutions and the advantages and disadvantages of various system architectures and associated business models. In this regard, new Smart Grid applications should be embedded in a reference architecture that forms the basis for developing standards. In order to benefit from the synergies discovered between Smart Grid applications, it is necessary to bundle the specifications of the individual technologies rather than view them separately. This will enable the creation of an efficient, generic and easy-to-extend basic infrastructure.
In order to be able to implement the results and findings of these projects to the entire energy system, an overall market model including relevant decision makers which support the energy transition, should be determined. On the way to achieve applicable smart infrastructure there are four main consecutive steps to be pursued (Figure 7). Within SGMS, after developing the individual applications, their system integration was subsequently combined, merged and developed synergistically. The next step entails an examination of the potential market based on developed technologies and the further development of applications into products suited to everyday life.
Figure 7: The steps in the way to “Smart Infrastructure” Salzburg
Focusing on demand response issues, the following subjects need to be highlighted:
– The interconnection between various development lines within the energy policy is necessary. For example political strategies for integration of PV units and incentives for the optimization of self consumption are two key leverages for supporting the development of load management.
– Currently, end users have limited choises such as selecting their energy suppliers but still have an inactive role in the energy system. Active participation of end users could support the grid operator as an alternative for grid expansion.
– One considerable obstacle to the integration of demand response is the structure of the current market model. For example, the balancing market is designed for centralized ancillary services. It is necessary to define new market players such as an aggregator or flexibility operator in order to allow the active element of the energy system participating in the energy market and support the efficient operation of the available infrastructure as much as possible.
– By defining relevant communication and security standards for the required interfaces in the smart infrastructure, not only does market entry become much easier, also investment security increases and development expenses decrease.
Based on mentioned challenges following adaptations should be considered for the integration of demand side management in the future Smart Grid:
– Defining the roles and reponsiblities for “behind-the-meter” activities
– Development of smart incentive schemes to promote active participation of flexible loads
– Integration of building automation systems into the Energy Performance of Building Directive (EPBD)
– Definition of flexibility operator
– Future obligation to connect charging stations for electric vehicles to a flexibility operator in order to enable controlled and adaptive charging
– Clarification of data privacy provisions when using smart metering
– Adjustments to measurement and calibration laws relating to smart meters, e.g. in order to extend service life and thus exchange periods
– Definition of standard requirements for EV charging stations
– Type and structure of flexible tariffs
– Specification and design of flexible tariffs
– Coordination of requirements in the electricity and telecommunication market with regard to synergies during a comprehensive expansion
Market model :
– Creation of market-based incentives for residential and industrial customers (e.g. flexible tariff structures, power and capacity orientated grid tariffs)
– Design principles for equal treatment of consumers and prosumers during integration into the grid controller
To overcome privacy concerns:
– Transmission of aggregated data
– Reduction of temporal resolution ? Incentive systems for the transmission of energy data
– Allowing intervention of residential consumers in the forecasts on load shifting
Table 1: Non-technical challenges regarding the integration of Demand Side Management
Up to now, there is no specific regulation for the integration of demand response into the energy system in Austria. Flexible demand can participate in various markets (day ahead, intraday, balancing/capacity market,..) based on current rules for other generation units. By defining new rules for the integration of demand response, the available potential of flexible demand in a Smart Grid will be effectively exploited.