This post is part of the continuing Paths to Transactive Energy series. You can find them all listed by clicking on the matching metatag at the bottom of each post.
One of the most influential insights into smart energy was defined by Robert Galvin in his vision for Perfect Power. Perfect Power turned the vision for the grid upside down, with each facility and each home responsible for its own power, acting as microgrids. These building-based microgrids would interact with their nearby peers, to gain resilience in operation and quality of supply across a neighborhood. Groups of neighborhoods would then interact at a larger scale. The Galvin Project promulgated the vision of Perfect Power, reliable, efficient, without single points of failure—and eventually the best way to incorporate distributed energy resources (DER) into the power supply.
The Galvin Perfect Power Model was abstracted into fractal microgrids, and demonstrated in the Camp Pendleton Fractal Microgrid Project. Fractal patterns are self-referential and self-similar.
A fractal system is one in which each part of has the same statistical character as the whole. Fractals are useful in modeling structures in which similar patterns recur at progressively smaller scales, and in describing partly random or chaotic phenomena such as crystal growth, fluid turbulence, and galaxy formation. In biological systems, simple genetic rules can create complex systems through re-application of simple genetic processes. There are no inherent limits to scaling fractal patterns up or scaling them down.
Transactive microgrids abstract complex components into self-similar systems that interact through common patterns of economic competition for resources. Whether the smallest system or the largest aggregate of systems that consumes, generates, or stores power, common interaction patterns define how each interacts with its peers.
Within each system of systems, these interaction patterns support efficient allocation and coordination of energy use within and among the smallest systems to create larger system or microgrid. These microgrids act as components that allocate and coordinate of energy use within and among their peers to operate still more complex systems. At each level, complexity and diversity, diversity of technology, of purpose, and of mission, is contained locally and managed locally.
Fractal system integration is inherently resilient. Systems command and control is managed locally, and only the information necessary to exchange services is shared. New systems can be integrated as components without increasing overall complexity. Larger systems can respond to degraded or damaged components by creating new spontaneous order.
Each node interacts with its peer nodes only in terms of the services, buying and supplying energy, consuming or curtailing use, and not in terms of process. Inside the box, which might be the BAS, is an algorithm or many that is outside the scope of the service interactions.
More than a decade ago, there was discussion on the smart toaster, the theoretical minimal system that could interact with the smart grid. Prices to devices was often discussed. The notion is that the grid does not need or want to understand a toaster, but only the toaster’s use or non-use of energy over a load curve. Transactive Energy, expressed as what we now call the common transactive services, defines the interaction patterns between systems that buy and sell power over time.
In this model, each integration, each customer gets to decide when transactive services stops and more traditional integration begins. So long as a system can participate in the containing grid with the common transactive services, the contents of the system are a black box; internal technology and algorithm are out of scope.
The Common Transactive Services (CTS) simplify define the interactions between and system and the microgrid it is participating in. CTS handles resources other than power, such as transport costs, congestion management, and ancillary services. Only the scale facto changes as we move up and down the fractal.