Anticipating the Smart Grid
Wireless technologies: In the U.S., the National Institute of Standards and Technology (NIST) has been tasked under the Energy Independence and Security Act of 2007 with creating the overall master plan of Smart Grid interoperability standards. Within that framework, IEEE is at the forefront of standards development to ensure uniformity and interoperability of the various components of the power production, metering, and data tracking on the Smart Grid. Of particular interest to building designers is a group of specialized standards developed under the IEEE 802 LAN/MAN Standards Committee. The various working groups under this committee are developing the protocols for local area networks and metropolitan area networks that are the foundation of the interconnectivity and communications needed to ensure secure, reliable data transfer from buildings all the way up to the power producers as part of the AMI. Of the myriad wireless protocols, most of the major technology vendors are using this technology instead of the technology used for cellular telephony. As such, there may be interoperability issues within the growing field of BAS wireless controls. As of last 2012, IEEE has adopted a new dedicated wireless protocol for emerging Smart Grid technologies commercially referred to as the wiSUN protocol, an open-source protocol based on IEEE 802.15.4g-2012, IEEE Standard for Local and Metropolitan Area Networks—Part 15.4: Low-Rate Wireless Personal Area Networks (LR-WPANs) Amendment 3: Physical Layer (PHY) Specifications for Low-Data-Rate, Wireless, Smart Metering Utility Networks, that operates in the 896-901 MHz, 901-202 MHz, 902–928 MHz, 928-960 MHz, 1427-1518 MHz, and 2,400–2,483.5 MHz bands within the U.S.
Integration of BAS with smart meters, power panels: To achieve a flexible power reduction scheme, it will be essential that HVAC and lighting controls are able to react to the Smart Grid’s AMI. This communication will allow selective shunting of segregated loads or partial reduction of targeted loads, depending on operational and life safety requirements. The nuances of the various categories in Table 1 and Figure 3 will require intimate communication between the AMI and not just the building level smart meter, but also with contractually defined specific power-consuming devices within a building under ADR schemes.
Without a solid understanding of these systems and hierarchy, there is great potential for abuse and unintended release of operation control for nonproportional compensation through utility incentives. Many of these instances of apparent utility takeover of private residences and commercial properties litter the typical Internet searches for the term “demand response.” In virtually every case, it was a situation where the building owner was uninformed about the agreements he or she was signing and what was expected in return for the financial incentives that were so gladly received.
Electrical and HVAC designers should be aware of standards that are being developed to establish an agreed-upon protocol for the communication of these systems with the technologies being developed within the AMI domain, which will intersect with the facility engineering domains at the smart meter. Of particular note will be ASHARAE Standard 201P (proposed)—Facility Smart Grid Information Model, which is currently under development in conjunction with NEMA to create uniformity in the communication between HVAC equipment, BAS, smart breakers and panels, lighting controls, and the AMI. This eventual standard, along with IEEE 802.15.4g, will enable the discrete control of virtually all energy consuming equipment to allow variable reduction in power consumption to meet negotiated power reduction targets of ADR agreements. By properly categorizing load centers and establishing a communication protocol between controlled equipment and the power source without and beyond the building envelope, all parties can benefit without surprises or sensational headlines in the media.
Locally produced renewables at the building level: Currently, an increasing number of large-scale renewable production facilities are being developed by the major power producers and their affiliates. Because they are developed with direct interaction with the power producers, they are directly connected to the power grid and integrated through the AMI. Point-of-use renewable energy technology—namely solar photovoltaic and wind power—is beginning to turn buildings into micro power generators. This brings opportunities for energy arbitrage through net metering while creating a more complex legal situation. The promise of a fully functional Smart Grid must also include a fairer and more interactive marketplace for locally produced renewable power at this micro scale of 10 MW or less. At present, customers may produce on-site wind or solar photovoltaic power to offset local building loads and back feed unused power to the local utility grid and reverse power usage charges. This activity is known in real time by the utility or the power producers to determine the magnitude of the aggregated regional load to establish a utility-level response back to the power producer whether or not additional power station resources are required for real-time loads. Similarly, weather predictive loads such as forecasted heat waves, high wind events, or similar meteorological forces can affect not only demand, but also local production capacity. However, utilities currently do not know the specific production at the individual building level unless smart meters are installed. Without that discrete knowledge, it is not possible to provide targeted incentives to individual customers.
IEEE has developed Standard 1547: Standard for Distributed Resources Interconnected with Electric Power Systems to help standardize the technologies and processes necessary to integrate these small organic producers into the overall AMI of utilities and power producers.
Electric vehicle technologies and the Smart Grid: Electric cars might become the grid’s first widespread energy storage system. Demand for building charging/discharging stations is increasing and along with other energy storage systems, they will need to be integrated into the AMI and DR agreements. To promote interoperability and standard design for plug-in electric vehicles (PEVs), NIST developed PAP (Priority Action Plan) 11: Common Object Models for Electric Transportation. PAP-11 will ensure that the grid can support the charging of the anticipated growing number of PEVs and optimize charging capabilities and vendor innovation. PAP-11 also supports energy storage integration with the local utility distribution grid, which is addressed separately under PAP-07: Energy Storage Interconnection Guidelines.
Opportunities on the horizon
The emerging Smart Grid offers tremendous promise for all levels of the power grid, but can also cause tremendous pain if not properly understood and implemented. Consider this introduction to some of the basic technology, developments, and pitfalls that owners, operators, and designers of the individual building should understand to position the building to take advantage of everything the emerging Smart Grid has to offer. By designing the power distribution system properly and understanding what operation controls owners are willing to cede to the power producers and utilities, the Smart Grid can offer significant financial incentives to building owners. The proactive owner who makes his or her buildings as smart as the grid is the one who will reap the rewards.
Smart panel and breaker implementation notes
1. The utility level smart meter is the gateway from the utility to the customer and is provided by the utility. Depending on the level of control that a customer is comfortable ceding to the utility in exchange for financial incentives, the gateway modem or other communication device can communicate with other smart controllers further down the distribution, either directly or indirectly through customer-initiated and directed BAS curtailment actions.
2. Lower level panelboard smart controllers are provided by the customer.
3. The designer must ensure that the communication protocols of the entire smart power system are compatible. Coordinate with the utility meter’s communication protocol.
4. The distribution level panelboards typically have RS-232 and/or dry contacts for local computer and/or BAS interfaces. Most manufacturers offer multiple channels to control a discrete number of breakers or groupings of breakers to allow zoning or variable levels of programmable control authority.
Sunondo Roy is vice president of CCJM Engineers. He is a cross-disciplinary engineer who has worked in educational, commercial, aviation, industrial, and institutional facilities for the past 25 years.
Joshua Polasky is an associate at CCJM Engineers, where he specializes in business process assessments and energy audits.
Blake Shanahan is an electrical engineering intern at CCJM Engineers who is pursuing his electrical engineering undergraduate degree at Northern Illinois University.
For further reading
The Smart Grid: An Introduction. Prepared for the U.S. Department of Energy by Litos Strategic Communication under contract No. DE-AC26-04NT41817, Subtask 560.01.04
Advanced Metering Infrastructure (AMI).Document # 1014793. Electric Power Research Institute, February 2007.