BTL Mark: Resolve interoperability issues & increase buyer confidence
The Building Services Interface
In my smart grid work, I began describing each end node as a microgrid. A microgrid is a self-contained entity responsible for managing its own energy use, generation, storage, conversion, and as a last resort, market operations. This model eliminates direct grid control of buildings. Maximum grid incentives, all delivered to a single energy services interface (ESI), the locus of market bidding for the building.
The ESI is the external face of the participants in smart energy. The ESI facilitates the communications among the entities that produce and distribute electricity and the entities that manage the consumption of electricity. An ESI may be in front of one system or several, one building or several, or even in front of a microgrid. In keeping with service integration principles, there is no direct interaction across the ESI.
Today, an ESI is most often on the outside of a building system. The leaders in commercial energy management, companies like Target, put the business between the ESI and the building systems. Target evaluates energy use, and changes in energy use as normal business decisions, and building systems respond to business operations. Target though, is unusually aware of its decision processes, has many nearly identical buildings, and has strict commissioning standards. For the rest of us to be like Target, we need a Building Systems Interface (BSI).
The BSI must expose several services. New systems will certainly incorporate the market-oriented interfaces of smart energy, for use inside the building microgrid. Other services will interact with the business, linking corporate calendars to building operations. Another will request and consume weather information; if nothing else, a data center should take advantage of a cold winter such as this to limit cooling loads.
Systems must tie their information to the space that the enterprise inhabits. It is not enough for points to self-describe themselves as an air handler—that air handler must describe itself in terms of the service it provides to a particular space. Space is what the building systems support, space is what the tenants recognize.
There is an enterprise service that links between the occupants and their activities and the BAS and its performance. It communicates to support business activities while using the common schedule communications developed for smart grids. It is aware of the market conditions and deals made with the grid though the ESI. It knows whether the volatile energy of the renewables-based grid is scarce or abundant. It can report back to the enterprise how and where energy is being used right now.
Even live-load, or plug-load, must be able to describe itself in relation to space. Panel sub-metering and BIM-based circuit tracing (PLie – panel layout information exchange) put even the coffee pot and copier as part of the BIM model for energy use. Even home appliances must be participants.
To be enterprise ready, the BSI must include discovery. Building systems, virtual meters for plug-load, and appliances should be discoverable using WS-Device Discovery. Common system metadata, the same that describes a collection of points as an air handler, must be package-able into WS-Device Profiles. Each device must expose both a system profile and an energy use profile (based on EMIX).
Because system metadata and profiles create business objects, this work creates the rational basis for policy-based security as applied to building systems. It is meaningless to ask if a system is secure unless you define what security means to you. Are you looking for a locked door, or are you looking for business enablement? (http://www.newdaedalus.com/articles/bouncer-or-prison-guard.html). System profiles bring building systems into normal security.
So what are the essential building services? There is energy management, accessible for low integration re-hosting in the clouds. There is performance contracting, also in the clouds. There is energy auditing, which only exists as a business based on near-zero integration costs (because the metadata is already in the BSI). Energy auditing? Well what if we call it a live LEED rating, or perhaps 3rd party verification of the performance of the performance contractors… BIFER (BI for emergency responders) may even come from that mix.
And, of course, there are the enterprise interactions, based on WS-Calendar.
This needs some standards to fly, to be cheap enough to let these cloud-based services flourish. I think we must advance PLie to a standard, probably as an extension to COBie. oBIX trends for energy management must be accessible from self-metering systems and from switch panels, and be able to support the NAESB Energy Usage Information standards. There must be a light-weight BIM, my vote is for GBXML, able to act as the spatial lens through which to view energy use. I want definitions for building system metadata and for energy profiles. Perhaps Specifier’s Property Information Exchange (SPie) should incorporate energy profiles.
Several of us are already discussing meetings in Las Vegas, when at the AHR Expo and ASHRAE come together. There will be announcements, I’m sure. If you would like me to inform you when meetings are set, drop me a line.
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