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Why New Daedalus?

Daedalus was the mythical great architect and artificer of the classical world. Today, embedded intelligence is enabling the most profound changes in the way we create and use buildings since his day.

Building Intelligence meets the Intelligent Building. The Intelligent Building negotiates with the Intelligent Grid. How will this transform how we interact with the physical world?

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Smoke Signals from the Energy Architecture workshop

I am not at the smart grid high level architecture workshop this week as Southern California Edison. Its members may be sworn to secrecy, or exhausted from long work, but are letting nothing out. The mere fact they are meeting, though, has caused numerous others to discuss the interface between the building/home/industry and grid, what we are starting to call X2G.

Three of the most prominent pre-standard specifications are OpenADR (Automated Demand Response), OpenAMI (Automated Metering Infrastructure), and OpenHAN (Home Area Network). In discussions around the formation of the OASIS Entergy Interoperability, someone asked “does OpenHAN define a gateway to OpenADR?”

The key architectural principles of symmetry, composition, and discoverability make this an unhelpful question. Every interface is a gateway, from one realm to another. That realm my include security changes, ownership changes, technology changes, and protocol changes. There may be significant operating requirement changes as well. For example, the definition of Real Time Response changes markedly as one moves from core transmission (very fast) to distribution, to home and building (relatively slow).

It is not the within the functions of the interface to define processes past the interface. This is why BACnet and LON and other building protocols proprietary and public have no place in the smart grid standards. This is why the industrial control protocols OPC has no place in the smart grid standards. OpenHAN is a special case, as it is a an in-building protocol created to meet the needs of the smart grid, but it, too, is not part of the smart grid interfaces.

I imagine two Service Entry Points for each [facility]. One offers time-sensitive two-way metering and also acts as a SCADA end point to improve customer service and diagnostics. The other offers a suite of services that I am calling the Energy Management Service (EMS). The EMS can be collocated on “the meter” or use a separate appliance and data path. This possible separation frees up today’s AMI installations to continue.

The EMS offers up multiple services to the smart grid. It provides an OpenADR endpoint to the grid operators. It manages market negotiations for energy purchases, generation, and storage. It relays curtailment signals, by which I mean the fast emergency load shedding signals.

The customer side of the EMS supports a more diverse set of tasks.

If the customer side of an EMS is above a private distribution network, it relays the OpenADR request on and aggregates the response into its own OpenADR response to the grid. Examples of private distribution networks include college campuses, corporate campuses, and military bases. Future distribution networks could encompass building floors in an office environment or even include the green neighborhood microgrid in a new subdivision.

A more common profile of the EMS might have some sort of building services network below, which would include the HAN. The customer side of the EMS could then be on the HAN, and the EMS would be a gateway. At a minimum, such an EMS would need to be able to poll the devices on the HAN. Some visions have an agent living on the EMS/HAN gateway, able to coordinate response from the agent-based devices below. Other business models see the EMS registering devices up to the utility and thereafter relaying direct control messages. In either case, the devices on the HAN see the message and coordination coming to them from the EMS.

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Reader Comments (1)

Toby: Feel free to edit and include the diagram we've been sharing on separting meter interface from EMS of the premises. I've also been thinking about this from the point of view of the plug-in electric vehicle (PEV). It also has a meter and EMS. The ability of this paradigm to work directly w/ an energy service provider or w/in a facility EMS should both be supported.

May 7, 2009 | Unregistered CommenterSteve Widergren

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