Smart buildings in smart grids KNX City Rafael Marculescu May 2013
Smart grids - definition A smart grid is a digital, self-healing energy system that delivers electricity or gas from generation sources, including distributed renewable, to points of consumption. It is capable of optimizing power delivery and facilitating two-way communication across the grid, enabling end-user energy management, minimizing power disruptions and transporting only the required amount of power. The result is lower cost to the utility and the customer, more reliable power and reduced carbon emissions. Source: World Economic Forum, Smart Grid Project Task Force & Steering Board The Smart Grid combines electricity and IT infrastructure to integrate and inter-connect all users (generators, operators, marketers, consumers etc) in order to continue to efficiently balance demand and supply over an increasingly complex network. 2
Why are smart buildings relevant Lighting, HVAC and water heat account ~50 of total residential used energy! 3
Problems to be solved in smart grid Total power consumption Overload management Renewable energy fluctuations How can be solved by smart buildings? By managing: Electrical vehicle charging (quick, eco, off mode) or discharging (used as a remote battery) HVAC management Hot water preparation White goods management Lighting management Multi buildings owners/companies Building management depends on electricity tariff (power availability) 4
Problems to be solved in smart grid - cont Observations regarding direct switching of loads by network operator/utility: Privacy issues! Right of customer to consume in spite of high tariff Appliances are changing elements in a home installation need to reestablish link between smart meter and new/repaired/updated home distribution network and/or appliances Stopping appliances in middle of program not always desirable 5
What will future communication look like in the cities of tomorrow? Future smart grids needs a IT-Communication Network Building automation: KNX already offers today the worldwide STANDARD for home and building control and ensures the compatibility of more than 7,000 certified components from over 300 manufacturers, speaking a common language: KNX KNX provides sensors and actuators for all application domains including the electric meter for measuring consumption, for example, as well as HVAC applications or electro mobility. KNX will provide all the necessary interfaces for communication infrastructures for smart grids, etc. in the KNX city of the future. 6
What is KNX? The three letters KNX stands for:. However. KNX is a bus system KNX brings building functions together KNX offers flexibility, safety, comfort and cost efficiency KNX is a world standard 7
KNX the world s only open STANDARD for home and building control European standard EN 50090 Worldwide standard ISO/IEC 14543 The KNX-system is truly open and platform independent guarantees multi-vendor and cross-discipline interoperability, ensured via certification is based on 23 years experience from the EIB market and the EIB technology and extended with additional media, configuration methods and experience from BatiBUS and EHS Several thousands of products from over 300 manufacturers (members of KNX Association) are easily available 8
Which components does the KNXsystem consist of? System components Components to build the communicating network, e.g. power supply Sensors Receives an external command Transform it to KNX-information Sends the information as telegram on the bus Actuators Receives telegram from the bus Processes the information Execute the function 9
KNX System components sensors Sensors (selection) KNX push-button Movement detector Room temperature control unit Binary input Anemometer 10
KNX System components actuators Actuators (selection) Switch actuator Dimming actuator Blind actuator KNX DALI- Gateway 11
The interaction between KNX and the intelligent power grid (smart grid) The following section presents five scenarios of a nested daily routine in the KNX city of the future: Scenario A: Excess renewable energy Scenario B: Insufficient renewable energy Scenario C: Peak load over the entire city Scenario D: Local voltage rise Scenario E: Local transformer overloading 12 Source: KNX Association
Scenario A: Excess renewable energy The network load in the city at night reaches its lowest level while at a time ample renewable energy is fed into the grid because of strong winds. This excess power should be used by the city. In order to do this, the excess is signaled to intelligent homes and apartments in the city by means of communication technology. They can then switch on loads connected by KNX such as water heating, domestic appliances and electric vehicles (ex: change from eco to quick charging mode). In this way, the energy supply is balanced out by means of KNX. 13 Source: KNX Association
Scenario B: Insufficient renewable energy This problem can be seen as complementary to Scenario A. By way of example, KNX city demonstrates the diminishing feed-in from the windpowered generators during the morning hours (stagnation). The city must respond by shedding some load, which is possible by means of KNX. The charging stations for electric vehicles are deactivated, domestic appliances are switched off and air conditioning units or heat pumps are set into Eco-mode. In this way, the energy supply is thus balanced out by means of KNX, without grid outage. 14 Source: KNX Association
Scenario C: Peak load over the entire city Particularly during the evening hours when city residents return home, peak loads are experienced in the household sector due to cooking, light usage in the evening hours, consumer electronics, domestic appliances and electric vehicles. This situation can be further aggravated by the service industries and local public transport. In this case, the loads can be reduced as already shown in Scenario B. Additionally, the energy stored in electrical vehicle batteries can feed the network. KNX not only helps to relieve the city s grid in this way, but provides support for it, as well. 15 Source: KNX Association
Scenario D: Local voltage rise Photovoltaic systems installed on rooftops and facades in the city feed the energy generated into the low-voltage network. During noon this can lead to a situation in a network segment where virtually no energy is taken from the higher voltage levels. In extreme cases, this can lead to unacceptable voltage increases. An intelligent energy supply with Smart Homes and Smart Apartments can work to counteract this problem by increasing the load on a local basis. For this to take place, the domestic appliances and electric vehicles can be switched on and air conditioning systems or heat pumps can be set to a comfort mode. KNX then helps to prevent a downward regulating of the photovoltaic feed-in. 16 Source: KNX Association
Scenario E: Local transformer overloading As already discussed in Scenario C, the highest network loading takes place during the evening hours. Before a situation similar to Scenario C arises, however, partial network overloading can already occur before that. This is typically transformer overloading, which might result when numerous electric vehicles are being charged at the same time. The vehicle charging process can be interrupted by means of KNX, alleviating the overload and preventing a local power outage. 17 Source: KNX Association
Questions? For more information about KNX technology and Schneider Electric training curriculum, please contact us at: rafael.marculescu@schneider-electric.com Please visit also: www.myenergyuniversity.com 18
Thank you! 19