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.

Update on 2009-05-07 21:35 by Toby Considine

As you can see in the comments, Steve has suggested that I share this diagram that, as I understand it,  arrived during a flight from China.

One detail to note is that the space outside the building is "Agregator Domain" - a term carefully chosen to avoid presupposing any existing business entities. For another take on this, see the comment left on my Cyborg Beetle article.

The Smart Grid is Not Faster RTUs

There is a growing awareness of cybersecurity for SCADA systems, one that has not, as of yet, brought anything like real security to SCADA in the power grid. SCADA (System Control And Data Acquisition) refers to the processes used for central control and operation of our biggest process systems. Process systems in this case include the distribution systems used for the electric grid and for water distribution systems: large not-very intelligent systems. I say not very intelligent because the often use a model in which each node is dumb as a thumb tack, and nearly as secure.

New business processes are demanding entrance. The utilities need DR (Demand-Response) to deal with their most pressing needs, but do not wish (for the most part) to share live metering data (“we think you should be happy with 15 minute intervals.”). We have a system architected so badly that “RTU interoperability” is considered some sort of holy grail. Perhaps this would be legitimate if RTU communications were some sort of high-performance wonder, but they are not.

New business models will break the old design philosophies. Distributed generation will mean that the substation operations you are monitoring will be controlled by someone else. Perhaps that someone else will include everyone with a zero net energy building. Perhaps that substation will be run by the Green HOA (Home Owners Association) set up by the large commodity builder complete with its own neighborhood generation.

This means you will have to assume that the substation is owned by someone else. This means that if you do have “one RTU incompatibility might take down the system” problems, then your system will be down. Failure to acknowledge this is just whistling past the graveyard.

The current power engineers run hierarchical end-to-end control systems than anyone. The question is, will this be like being one of the folks who understands SNA best, claiming to the end that only structured hierarchical controls can keep things afloat, while folks like NERC acknowledge greater instability every week.

Things will change. That change will involve embracing multi-party communications at the substation and at the end node. Thos multi-party communications will require something better than sealed end-to-end channels.

This is the way the tides are going. The choice is to promote the desirability of holding back the tide, or to acknowledge the rising damp.

Federated security. Multi-party communications. New market models.

Embrace them or become obsolete. The smart grid is more than just upping the speed of communications with your RTU.

Natural Gas and Perfect Power

We are misusing natural gas in our power plants. Guided by strong emotions and the search for the quick fix, we are reducing the long term reliability and sustainability of our energy infrastructure. When well meant but bad decisions reduce the common good, we call it the tragedy of the commons. Technology and modern public interest groups let us recreate the tragedy of the commons on a larger scale.

Perfect Power is what Kurt Yeager and the Galvin Electricity Initiative call their version of the smart grid. Perfect Power assumes that the national power grid will not and cannot be made reliable enough for the digital world. Attempts to make the grid reliable cost a lot of money and waste a lot of power. Attempts to make the grid reliable interfere with the grid being the most efficient market place of energy possible, and able to accept innovation, diversity, and change. Perfect power reliability starts in the home and building, which must be responsible for their own reliability and quality. Groups of homes and buildings can band together in microgrids to enhance that reliability and provide each other with robustness. These microgrids can then buy from the grid when their needs and desires warrant, and when the prices are good. The grid, freed from the mandate to do what it cannot, will become easier and less expensive to operate.

Net Zero Energy and Distributed Generation are different perspectives on the perfect power vision. Buildings that are able to store, generate, recycle, and convert energy, can buy when they want, can sell when they can, and are reliable whatever the grid provides. Microgrids expand the options for energy storage, recycling and re-use even we add distributed generation. Distributed generation can get us past the restrictions of the regulated “natural monopoly” of power.

I have written before that I wanted my home heating system to see gas as well as electrical prices. Regular readers know that I recently installed a hybrid system that switches from heat pump to gas furnace based upon outdoor air temperature. This automatic cut-over is based on computed heat-pump efficiency. The cut-over should be based upon the current price of each energy source, factored by each system’s internal performance diagnostics.

At my annual Caroling Party, conversations naturally turned to the new purchase, who installed it, and was I satisfied. One party-goer was concerned that the high efficiency furnace was still producing greenhouse gases. I mused that even if the power company was better than the 95% condensing furnace, the local fuel did not suffer from the inefficiencies of converting heat to electricity, and of then transmitting it for many miles, and then converting it back to heat. Local efficiency numbers, from local energy use, are simpler and easier to understand.

Another guest, a long time gas company engineer, pointed out that natural gas has its own Demand-Response system. Demand-Response refers to the approaches and technology used by the electrical providers to manage peak capacity by seasonal, daily, and emergency communications with its customers. During periods of peak use, the pressure in the natural gas distribution system can drop to low levels. If it drops too far, pressure valves automatically shut off in homes and businesses. These brown-outs are much more expensive to recover from than electrical black-outs. Utility employees must turn off each gas meter before a local loop can be restored lest appliances with pilot lights become explosion hazards. Gas companies handles these low pressure incidents by calling large industrial customers and negotiating reduced use.

All of the same AMI/AMR conversations of the power grid apply naturally to natural gas distribution. The costs savings and efficiencies of automated cut-off of service can offer even greater benefits, when needed, to the gas company than they do to the electrical company. Gas distribution can benefit from dynamic pricing for capacity management just as does electrical distribution. If I had dynamic pricing, then I could factor it automatically, along with electrical pricing, into my home heating operations.

All of the concepts above apply to generation as well. Perfect power and E-tech will include conventional generation as well as exotic technologies such as gas-based fuel cells. Natural Gas will need many of the same service interfaces as electricity.

Stability and robustness in ecosystems comes from diversity of species. Stability and robustness of energy in the home and office will come best from diversity of energy sources, including those from outside the building as well as those generated internally. There are few sources of energy that are easy to transmit to each site of final use. We should not waste them all in central generation plants. We should use them to expand the robustness and diversity of energy in each building and in each microgrid.

A pricing Service for Electricity

What price structures are necessary to enable fully symmetric negotiations over power purchase and sale? Over at the NIST TWIKI, Marty Burns, Bill Cox, and I ironed out the requirements for a pricing service for electricity. Comments are welcome.

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What are the requirements for communicating price across the smart grid? What pricing structures are in use or under development now? How do we move to a common information element, common whatever else needed for prices?

Note: It is important to emphasize that these are requirements for a solution set for pricing services. Therefore all the following requirements are not necessarily simultaneously applied to any particular single service based on the ensuing model.

Due to potentially [rapidly] changing roles, we use the terms supplier and consumer rather than utility and customer. With aggregators, these terms are still more general.

This page was created and modified by Marty Burns, Toby Considine, and William Cox, for discussion among the DEWGs.

Pricing Requirements

Dynamic pricing enables dynamic power management and includes both:

1) the realtime response of automation systems to "realtime" grid pricing and

2) the managed response of consumer management and planning systems to supplier/grid price forecasts.

1.1 Regulatory/Policy

• 1.1.1 Metering, Billing, and Collections are separate processes / services from power delivery.
• 1.1.2 Aggregation and Delegation should be explicitly permitted for all operations.
• 1.1.3 The pricing model is not explicitly tied to any particular regulatory environment.
• 1.1.4 Barriers to symmetric operations should be eliminated.
  • 1.1.4.1 Suppliers and consumers may exchange roles at frequent intervals.
• 1.1.5 Businesses willl handle traditional business processes as they do now.

1.2 Business Objectives

• 1.2.1 Suppliers are able to provide automated dynamic pricing information to consumers.
• 1.2.2 Pricing is able to support active power management and optimization.
  • 1.2.2.1 Price adjustments can be made in time in up near real time manner.
  • 1.2.2.2 Prices may include commitment enforcement in support of a variety of scenarios, including both minimum and maximum commitments.
• 1.2.3 Pricing should be available for a variety of deliverables.
  • 1.2.3.1 Power Consumption.
  • 1.2.3.2 Peak Availability.
  • 1.2.3.3 Relinquishment of prior right (Differential Behavior vs Absolute Consumption).
  • 1.2.3.4 Power Quality.
  • 1.2.3.5 Carbon Offsets.
  • 1.2.3.6 Transmission and Congestion.
• 1.2.4 Pricing should support the decommoditization of power.
  • 1.2.4.1 Wind, Distance, Carbon, Triple Bottom Line, and other attributes.
• 1.2.5 Pricing should be time sensitive.
  • 1.2.5.1 Time offer made.
  • 1.2.5.2 Window for offer.
  • 1.2.5.3 Time of acceptance.
  • 1.2.5.4 Scheduled Time of consumption.
  • 1.2.5.5 Actual Time of Aggregation.

1.3 Business Procedures

• 1.3.1 A set of core processes and transactions will be defined.
• 1.3.2 A service to support each core process will be defined.
• 1.3.3 A common service framework will be defined to support all services.
• 1.3.4 Market operations should support unidirectional price announcements.
• 1.3.5 Market operations should support bidirectional bidding.

1.4 Business Context

• 1.4.1 Legacy pricing models need not be supported by the new interfaces.
• 1.4.2 Legacy business processes need not flow through new interfaces.
• 1.4.3 Requirements to continue traditional business processes may be met outside of the new interface.

1.5 Semantic Understanding

• 1.5.1 Must accommodate wide range of Pricing Models.
• 1.5.2 All Pricing Models should contain a common set of properties.
• 1.5.3 Many Pricing Models may be in effect concurrently.
• 1.5.4 Pricing Models will change over time and must be discoverable.

1.6 Interaction Model.

• 1.6.1 All intereactions will be messaging based.
  • 1.6.1.1 synchronous request-response pull.
  • 1.6.1.2 asynchronous publish-subscribe push.
• 1.6.2 Symmetry should be supported at all interfaces.
• 1.6.3 Best Efforts message delivery shall be supported.
• 1.6.4 Security and Privacy must be designed into the model.
  • 1.6.4.1 Authentication is often required.
  • 1.6.4.2 Guaranteed message delivery shall be supported.
  • 1.6.4.3 Non-repudiated message delivery shall be supported.
  • 1.6.4.4 Private message delivery shall be supported.
• 1.6.5 Delegation of message handling shall be supported.