Building Integration with Smart Grid

Summary

Developing a next generation "smart grid" requires new measurement science and industry standards that enable homes and buildings to interact with the grid. In the United States, commercial and residential buildings consume 72% of all electricity[1]. As building-scale renewable energy systems become more common, buildings will increasingly become generators of electricity as well as consumers. Future electric vehicles will be charged through plug-in connections managed by home and building automation systems. Utility-scale renewable generation systems will require responsive loads to match the fluctuations caused by varying wind and solar conditions. Consumers will need access to their own energy consumption data to make informed decisions about their energy consuming habits. For all these reasons, integration of building systems with the grid is a critical part of the stability and success of the smart grid.

Description

Objective - To develop the measurement science for industry standards that will enable interconnection of home and building automation and control systems with a future "smart" utility grid, provide consumers with energy usage information, and support industry efforts to develop the needed standards.

What is the new technical idea?  The NIST Smart Grid Interoperability Framework 4.0 makes clear that the grid is evolving toward more intelligent devices and generation sources at the grid edge. These include intelligent AC-powered devices (e.g., home heat pump and water heater) and DC-powered (and generating) devices like photovoltaic panels, batteries, LED lighting, and electronic devices. Collectively these intelligent devices and systems are called distributed energy resources (DER). These DER can provide frequency and voltage control services to the grid but may also impact the power quality of the building and local grid itself. Power quality may be affected by real and reactive power production and consumption, by fast response of multiple devices, and even high-frequency noise from inverters and rectifiers that connect the AC grid to the DC-powered devices. The complex electrical interactions of the grid and the building need to be understood. The set of standard communication interfaces to enable customer DER integration needs to be developed.

The new technical idea is to integrate homes and commercial buildings into the next generation “smart grid” by developing the technical basis for standards governing local energy market communications, integration of DER (including intelligent loads, distributed generation, and energy storage), electric vehicle managed charging, and consumer access to energy usage information. This project will develop information models, data representation methods, and communication protocols to enable these activities, working with industry stakeholders to analyze use cases and develop approaches that can be adopted through consensus standards. In addition, this project will involve research into novel facility control methodologies based on DER availability, electricity price, and local markets, with testing in a simulation environment, in the NIST Smart Grid Testbed, and in the NIST Net Zero Energy Residential Test Facility (NZERTF).

What is the research plan? 
This project addresses communications, interoperability, and control approaches for residential, commercial, institutional and industrial buildings via three research components: (1) information model development to enable data exchange within building systems and between buildings and the smart grid, (2) building controls research for optimal response to dynamic pricing and demand management signals in commercial and residential buildings, and (3) simulation and laboratory testing. EL collaborates with industry stakeholders in the Smart Electric Power Alliance (SEPA) to identify interoperability standard gaps and research needs. 

The information modeling effort includes definition of the building-to-grid communications interface, identifying key information elements needed for grid-to-facility communications, and development of priority facility interface standards as identified in the NIST Smart Grid Framework.  This work is input to the development and maintenance of several standards:
Information modeling standards

• American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE)/ National Electrical Manufacturers Association Facility Smart Grid Information Model 
• North American Energy Standards Board (NAESB) REQ.18/WEQ.19 Energy Usage Information standard
• Organization for the Advancement of Structured Information Standards (OASIS) Energy Market Information eXchange (EMIX) standard for price

Protocol implementation standards

• NAESB REQ.21 Energy Service Provider Interface (ESPI)
• OASIS Energy Interoperation for DR signals and market interactions
• Electrotechnical Commission (IEC) 62746-10-1 Open Automated Demand Response (OpenADR)
• Extensions to ASHRAE Building Automation Control Network standard (BACnet) for meter, price and distributed energy resource communications
• Extension to BACnet web services to support Energy Interoperation
• Standards for residential appliances and industrial process control implementation

The building controls research component will develop load and generation prediction algorithms, and demand response optimization strategies for residential and commercial building interaction with the smart grid. These algorithms will consider: demand response signals; future electricity price, weather and occupancy information; availability of renewable energy (including storage); and user inputs. 

The simulation and testing component will utilize unique NIST laboratory facilities (VCBT, NZERTF, and Smart Grid Testbed) to test and demonstrate success of the information models and control strategies, and provide input into building codes and standards. EL will study the impact of individual devices on distribution grid power quality and operations, including capability to provide grid services. In addition, EL will work with external partners to strengthen transactive energy simulation models and tools. EL will also support the broader NIST smart grid program, providing technical direction and leadership within the SEPA on issues related to building interactions with the smart grid. EL will provide leadership within ASHRAE, OASIS, NAESB, and IEC to advance the standards listed above.

Major Accomplishments

Some recent accomplishments for the Building Integration with Smart Grid:

• Approval of Open ADR 2.0b as IEC Publically Available Specification.
• Draft ASHRAE/NEMA Facility Smart Grid Information Model standard
• Energy Interoperation approved as OASIS Standard.
• Green Button Alliance testing and certification process established
• Green Button Download My Data and Connect My Data programs implemented in 48+ utilities with 10s of millions of customers nationwide, providing access and apps to help customers understand and improve their energy usage.
• OASIS Energy Interoperation adopted as a committee draft within IEC PC118 for development to become an international standard. Open source implementation of Green Button Connect My Data has been developed and now has been deployed by a utility.
• Publication of IEC Technical Report that presents the case for advancing U.S. developed Smart Grid standards to international standard status.
• Publication of Vehicle-to-Grid standards roadmap.
• Published OASIS Energy Market Information Exchange standard (EMIX). 

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Reference Documents:

[1] DOE Buildings Energy Data Book http://buildingsdatabook.eren.doe.gov

[2] NIST Special Publication 1108R2, NIST Framework and Roadmap for Smart Grid Interoperability Standards, February 2012.