As I do periodically, I have been thinking about what standards we need for the smart grid. The smart grid is more than improved top-down control, it is a grid ready for unreliable energy sources (such as wind, waves, and sun), distributed generation, and net zero energy buildings. Net zero energy buildings are particularly troublesome because from minute to minute, they may be buy power or selling power. The smart grid will be transactional, with each purchase of energy at a market clearing price. The smart grid will be open and transparent, wherein consumers can choose what kind of power to buy, and providers can prove that they are selling the kind of power they promise.
Earlier this week, Alex Levinson referred to the suite of standards we will need for the smart grid as Smart Grid Information Exchange (SGIX). So what are the standards we need for SGIX?
- SG Pricing: Price is more than a number. If I ask you if prices are up or down at the store, the answer is not “7”. It is not “Tomatoes are $3.00.” The price is “$3.57 per pound for the organic vine-ripened greenhouse heritage Cherokee tomatoes.” Each buyer can choose which attributes affect their purchase decision. I may choose to buy the cheapest tomatoes. I may choose to buy only organic. I may grudgingly choose the most expensive because they are the only ones in the store. And I will be able to choose to run the fountain in front of my office only when wind power is available and below a certain price.
- SG Transaction: I buy what I buy at the time that I buy it. That transaction may be different because of my price decisions than what my neighbor is buying at the same time. I may owe for that purchase of solar power to my utility or to my neighbor.
- SG Market Operations: There is some bidding and exchange of information in advance. In my mind, this looks somewhat like commodity markets for those who want to participate. It includes elements of weather arbitrage. It includes time and reliability. It includes all of the elements of price. I am looking forward to GridEcon in March to begin the discussions on SG Market Operations.
- UnitsML: UnitsML offers an unambiguous way to describe all physical measurements, and an unambiguous ability for a computer to look up the translation of any units of measure to any other units. I think UnitsML will be part of pricing and market operations
- WS Calendar: We all use ICALENDAR to unambiguously exchange information about time intervals. You used it the last time you clicked on an email attachment and suddenly had a meeting on your personal calendar. We need the same functionality standardized for web services. We will use it as part of pricing, and weather predictions, and other decisions.
- WeatherML v2: I don’t actually know what version WeatherML is on – but it is not usable. Most forward looking energy markets are based on assumptions about weather. Most historical analysis of energy use includes recalling the weather environment. The most successful energy middleman base their business on understanding microclimates. We need a standard way to report weather information, in whatever detail is available, from forecasters, local weather stations, personal weather systems. Such a standard should include UnitsML (for internationalization) as well as time (WS-Calendar) and probabilities (for forecasts).
- SG Interoperation: I envision this as a short, light, exchange of the information we need to plug technologies together without knowing the details. I see it as smaller than, but perhaps derived from, ISO-61850. It includes some basic safety information. It includes estimates of reliability and capacity. It may include some of the “price attributes” (Am I a source of carbon-credit eligible power?).
- SG Metering: This is a simple standard of energy flows by time slice. It also includes direction, as power may flow one way for a time, and then the other in a distributed world.
- oBIX: The web service standard for technology-agnostic operation or distributed control systems could well have a place Remote Operation and Telemetry.
- SG Telemetry: What is going on on the grid, and where is it failing.
- WS DD and WS DP: Device discovery and device profiles have been used in computer networking for some time. Device Discovery lets you find all printers on the network,. Device profiles let you decide which printer to use when you want color duplexing. These functions are being standardized for the web. Schneider, one of the largest conglomerates providing systems for the grid and building is looking at providing WS DD and WS DP for all the equipment it sells. I think it will have a big role in the future world of distributed generation and net zero energy.
- SG Remote Operation: This one may be a literal transform from the ISO 61850 standard for substation communications.
Have I missed any partis of SGIX?
There is nothing like publishing to make your spelling errors and your ommissions come to light. Some things I left out:
- SG Curtailment. Sometimes, no matter how you plan, stuff happens. The daily temperature is 5 degrees warmer than expected. The tubine throws a spandrel. A truck drives into the tramission tower. Shed load NOW!
- SG QOS: Somehow we have to exchange information about Quality of Service, both as a promise, and as a result. I hear hints that we may be able to find QOS communication standards in another standard. Perhaps one of my readers can suggest a pointer...