You’ve heard a lot of talk about the deployment of the Smart Grid. Most of the initial smart grid deployments are focused on the deployment of smart meters that enable utilities to gather usage information in near real time — or what they call Automated Meter Infrastructure (AMI). The use of AMI provides a number of benefits, including more accurate billing and improved service, easier provisioning (turning power on or off to a customer), accessibility of use data by customers, and use of time of day or real time rates.
The smart grid also opens up the potential for a series of new applications including the use of more distributed power and micro-grids that will result in improved grid resiliency. For commercial buildings, we should expect that the smart grid will provide a series of solutions that are loosely called “Building to Grid” or B2G. In short, these are solutions that will better balance commercial building loads with the capacity of the grid. It is important to understand what is coming so that you can design to accommodate systems that are B2G-ready.
Today, there are two primary B2G strategies that you can deploy, both of which are designed around the management of electrical demand. The first approach is the use of traditional demand limiting. This approach provides the ability to reduce monthly (and often recurring) demand charges by measuring peak demand and staying below preset levels by extending setpoints or turning off loads. Demand limiting is an effective strategy to reduce demand charges but works independently of the needs of the grid — so it would not truly be considered to be B2G.
The other common approach is the use of demand response (DR) where the building energy demand is reduced based upon a signal provided by the utility, grid operator, or a third-party aggregator. Building demand can be reduced through several different strategies including extending setpoints, turning off loads, switching to thermal storage or gas cooling, or utilizing co-generation or standby generation. Most DR programs provide payments to owners for participation as well as for each kW (or kW/h) reduced.
DR programs are utilized for a limited number of hours or events per year, and generally owners are only asked to participate during the hottest days of summer. A DR event can be deployed manually (based on a phone call, e-mail, or fax) or automatically using a signal that can be directly connected into a BAS. We would strongly encourage designing a new (or upgraded) system with the use of automated DR as part of the design. This would include points and sequences specifically focused on DR. It also requires some research as to available local programs and how they get triggered.
While automatic demand response is the current state of the art in B2G integration, expect future programs to take this even further, allowing for more dynamic and continued interactions to provide for a more dynamic balance between the demand for electric power and the varying capacity of the grid.
