Plug-In Hybrid Electric Vehicles (PHEV)
Associated with buildings are the cars that are driven to and from the building, usually resulting in a significant portion of surface use or facilities for parking cars. Add to that the gradual penetration of hybrid and electric cars that need to be connected to the grid to be recharged that are also capable of storing electric power and providing it back to the grid. This is somewhat futuristic given the currently small number of PHEVs and the lack of advanced batteries but the potential over the next decade is huge. The general idea is that PHEVs could be recharged at off peak hours (middle of the night) and store energy that could be transferred to the grid during peak load times. It may not be as easy as it sounds. When the PHEV gets recharged will depend on when the driver wants to use the car, how much the batteries are discharged and what the time-of-day energy rate is. This area is much like distributed generation where the standards for bi-directional flows of energy and two-way communication and control capabilities are lacking.

Building Control Systems and Devices
A smart grid that simply provides energy information to home owners and building owners, and presumes that they will manually turn off lights and equipment and reset thermostats will flounder. To a large extent, the success of the smart grid will depend on the control systems within the buildings and the seamless and automated interaction between the building and the grid. Most buildings will need to integrate their control sub-systems, provide more sensors for the sub-systems and larger buildings will need to provide sub-metering. Proprietary building control systems will be unable to communicate and interact with the grid without some gateway or middleware. BACnet is identified in the first draft of operational standards as the preferred facility communication protocol for the meter interface. Here are some examples of how this may play out for residential, commercial and institutional buildings.

For residential the typical setup for a demand response program will be smart thermostats, control switches on the air conditioning and water heater and a display for providing energy information. Smart thermostats will allow a homeowner to set the temperature but outside of a certain range around the set point, the utility grid would control temperature. The same is true for switches on air conditioning and major equipment.

Larger commercial and institutional buildings will probably need to upgrade and integrate their building control systems, install metering systems with sufficient granularity, and potentially address the connection of wind, thermal and solar energy sources into the grid. Interestingly, one of the recent Smart Grid Investment Grants from the US government went to Honeywell ($11.4 million). They will provide automated peak pricing response for about 700 customers. Honeywell is planning a two step approach: first work with customers to develop a schedule of which equipment, banks of lights and power loads can be reduced during peak pricing and for how long; the second step utilizing their Tridium platform with the Open ADR standard to communicate with the grid and in turn control the building systems.

Standards and Protocols
The National Institute of Science and Technology (NIST) is responsible for coordinating the identification and development of the protocols and standards to achieve interoperability of Smart Grid devices and systems. After several iterations and public hearings for comment they released a draft report in September. NIST has identified applicable existing standards and also gaps where standards will need to be developed. The priority areas include: demand response, consumer energy efficiency, wide area situational awareness, electric storage, electric transportation, advanced metering infrastructure, distribution grid management, cyber security and network communications. They have identified 77 standards or specifications that can be used in the Smart Grid. Sixteen standards were initially identified as having strong consensus; that was expanded to 31 after public comment. An additional 46 standards were identified as potentially applicable. For those areas where gaps were identified, such as demand response, end-user energy information, time synchronization and so forth, draft standards are expected to be released in 2010.

What are the standards that have been identified that are most important for buildings? Out of the 77 here’s a list of the standards that could impact a building’s interaction with the Smart Grid:

For more information about smart buildings, technology design or to schedule a Continuing Education program, email me at jsinopoli@smart-buildings.com .

Jim Sinopoli, PE, LEED AP, RCDD
Managing Principal, Smart Buildings LLC