The electrical utility grid that Thomas Edison initiated over 100 years ago is long overdue for an overhaul. It will be a 180 degree change in the utility business model, going from selling more and more energy to consumers to putting everyone on a healthy energy “diet”.  The entire concept of the utility grid, buildings, vehicles, energy sources and energy storage all communicating with one another to enable the efficient use of energy is ambitious and breathtaking. It will be the details of implementation that will determine its success.

Much of the Smart Grid is obviously focused on utility grids, not necessarily buildings. However, some of the characteristics of the Smart Grid effort addresses the integration of distributed energy resources, demand response, demand-side resources, ‘‘smart’’ appliances and consumer devices, plug-in electric and hybrid electric vehicles, thermal-storage air conditioning, and timely information and control options for consumers. Intuitively we know that a smart grid without smart buildings would be a greatly diminished deployment and a very expensive lost opportunity.

The larger question is what are the attributes and characteristics of the connection between smart buildings and the smart grid? What are the applications? What is the communications interface? How will it be addressed technically? What could or will it mean for building owners and facility management? Buildings are being designed and upgraded to be energy efficient but that effort often is disconnected from the Smart Grid initiative- how do we get the two in sync? Let’s start with the possibilities of applications and then review the possible communications protocols.

© Electric Power Research Institute

Demand Response
One of the top priorities of the Smart Grid is demand response, an economic mechanism to have customers reduce or increase demand. When used to reduce demand, utilities reduce their peak demand and the additional need for plant and the related capital costs. Using demand response for increasing demand is intriguing. During periods of low demand and high production a utility may want to increase demand to users that can store the energy and make use of the energy later (much like charging a big battery at the customer’s site).

The communications between the grid and a building can be two-way with the grid initiating communications to the building and the building acknowledging the signal and letting the utility know of their capability to respond. The building owner’s response to a demand response notification can be manual or automated. Manual response means people go around and shut lights off or turn thermostats down, obviously an inefficient and somewhat ineffective action to a signal from a technology-laden utility grid.

Automated means the grid signals the building and the building systems automatically respond by turning off lights and equipment, adjusting set points, etc. How this communications between the grid and the building systems takes place is still being worked out. If the demand response is “anticipated” it is possible that typical building systems in non-residential buildings may be able to be scheduled to react. If it’s dynamic however, as utility rates are projected to be, the grid must communicate real time with the building systems. The basis of that communication appears to be open standards‐based technology such as XML, SOAP and Web services, as indicated in version one of an Open Automated Demand Response communications specification. The communications standards for pricing formats and time-of-day schedules need to be established. While that framework looks solid it would take some advanced or enhanced building management systems to accommodate that communication and in turn adjust the energy-related building systems. The number of existing buildings that are currently capable of doing so is very small.

Distributed Generation (DG)
As more alternative on-site energy sources (solar, wind, co-gen) are used, buildings will be seen as both energy consumer and potential energy provider. As an energy provider the building or campus could supply energy back to the grid. That integration of on-site energy generation into the grid will require much more than communication. It also needs to address the verifying of the quality of the energy provided, security and safety. The movement of energy back and forth from the grid is another important area where standards will need to be developed.

Energy Information to Consumers
Consumers will need information which can assist them in energy management. Some of the information and data may come from the grid and some may come from the building systems. For residential applications this data and information could include:

• Energy use – real-time and historic data on the amount used (KWH) , the cost, the rate schedule or purchasing terms for energy, the trends and the projected forecast of usage and costs
• Power sources  - the amount and cost of renewable energy sources that are used, the carbon content of the energy used, and the distance from energy source
• Weather forecasts
• The quality and reliability of the power

For larger commercial customers this information will need to be more granular, more technical and in line with the reporting requirements for cap-and-trade, LEED, Energy Star or government requirements. Any information from the grid will need to be supplemented with information from the building systems.

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