Eight Agents for Energy

The Energy Mashup Lab (The Lab) is developing open source software for agents that will enable systems that use, produce, or store energy to self-assemble into microgrids. These microgrids can be standalone or grid-attached. If grid-attached, they present a single market or OpenADR interface to the grid, and that interface reveals only the net market position of the microgrid.

The microgrid is operated by a micromarket, trading in availability over time. The Lab uses open standards to transact between agents. Each system or group of systems being represented by an autonomous merchant agent that buys or sells Power for those systems. The software for this agent is Open Source and can be freely downloaded for use in products.

While there is a simplicity in a single Agent, we think there are benefits to creating more than one type of agent. While a single agent running a single set of code could encompass all behaviors could be created, agents that are optimized for specific types of market behavior can be smaller and more secure. Naming similar market behaviors across systems makes it easier for the integrator to understand how introducing an additional system will affect an existing micromarket/microgrid. We name these the Agent Personalities.

The descriptions below refer to electric power for clarity and brevity. The agent behaviors apply to any resource micromarket.

The Simple Agent Personalities

Each Agent Personality denotes a common set of market behaviors.

Homeostasis Agent

A homeostasis agent represents a system that consumes power episodically to support it’s a purpose external to the resource market. A homeostatic agent schedules power purchases to support providing a service external to the grid.

Two examples of systems that would use a Homeostatic Agent are an air conditioning system and a refrigerator. Each of them buys power to support processes that support a service external to the grid. Neither wants to run unless it is able to buy the entire power curve it needs for its next cycle. Each could advance or delay its purchases to some, or even skip a cycle, without harming the service it provides.

Preconsumption Agent

A pre-consumption agent is similar to the homeostatic agent, but it provides an asynchronous server and therefore has a bias to buying only when the price is low. The system is able to increase consumption in the short term to enhance its ability to provide service at a future time. If the refrigerator is a homeostatic agent, the ice-maker may be a pre-consumption agent. There may be overrides to the behavior, i.e., fill up before the party, or high priority when less than a quarter full.

Base Consumer

Base Consumer uses power continuously when the system it represents is providing a service. An example is a light which is either lit and consuming power, or is unlit and not consuming power. An agent representing one or many lightbulbs on a circuit changes in scale only. A base consumer is almost always a high-priority purchaser in the market.

Tiered Consumer

A Tiered Consumer differs from a Base Consumer in that it may be able to reduce power consumption by providing a lower level of services. An example is a dimmable light. More power might provide a better service, or a different service. Using for example the dimmable light again, a low level of light might support movement, a high level of light support reading, and a higher level of light support personal grooming.

Base Supplier

A Base Supplier supplies power continuously. A Base Supplier might include any controllable generator with a long cycle time. Long cycle time is situationally defined.

Market-Driven Supplier

A Market Driven Supplier supplies power intermittently, based on interactions within the microgrid.

Intermittent Supplier

An Intermittent Market Supplier supplies power intermittently, based upon inputs external to the microgrid. An example is a photovoltaic system, which generates power when the sun shines.

Storage Agent

A Storage Agent is able to consume resources later supply the same resource. It stores power. This is similar to a system able to pre-consume, but it is able to bring some portion of its pre-consumption back to the market at a later time.

The Platform Agents

Any of the Agents Personalities named above can in principal interact with any other agent through bilateral transactions. Some markets might be set up with all tenders going to a single entity who manages all transactions.

Broker

The Broker acts as an agent by executing public orders. It may operate a double auction. The Broker does not itself have a position in any trade. (Transactions to power the broker are an exception). In the home, a home router may act as a broker.

Market Maker

A Market Maker acts as a Broker by executing public orders left. It Market Maker further maintains an orderly resource market with a responsibility to buy for its own account in the absence of public buy orders, and sell from its own account in the absence of public sell orders. The market Maker personality may be associated with Storage or with external market sales and purchases. External market sales and purchases are not part of the internal maker that operates the microgrid.

How to use the Agents

Each of the simple agent personalities could characterize a single node or a collection of nodes. Microgrids can be characterized just as nodes are characterized. This point is fundamental to considering interactions within aggregations of microgrids, as to considering the dis-aggregation if a node into smaller component systems.

A system or device developer will be able to select the personality that he desires to represent his technology, and download it.

A set of agents sufficient to support systems with each of these characteristics is able to support all systems potentially within a microgrid. Such a set does not rule out potential hybrid systems, in which two or more of these characteristics coexist within a single system—such a system is a natural outcome of a microgrid at one level being a node at a higher level.

Small Transactions and Smart Energy

The problem of smart energy is distributed intermittent generation laid across unmanageable power use and a fixed distribution grid. Central operators will never be able to keep pace with controlling new technologies that generate, store, and use power. Privacy demands that central operators not track and predict every activity in our homes and buildings. In economic terms, this is a knowledge problem

Markets are a proven means to balance supply and demand without central control. In 1992, Huberman & Clearwater demonstrated that a market in data center cooling better optimized allocation and reduced energy use than the best control strategies. The technique they used in data center at XEROX PARC was to add an agent to each server and have each agent bid for cooling.

The best place to manage the changing technology mix for power and changing demands on systems is locally, in a microgrid. Within a microgrid, each system can bid to buy or sell power over time, aligning demand with supply, smoothing load, and managing storage—each microgrid can be operated by a micromarket. Each system and application can be represented by a market agent. Each market agent represents the needs of its system and the preferences of tis owner. Smart energy is an emergent behavior of the IoT market.

Every microgrid can participate as a node in a containing grid. Each microgrid shares only its aggregate market position with the containing grid. Microgrids gain resilience through buying and selling power to and from their peers. This model is fractal, as the term microgrid can refer to the city, the neighborhood, the street, the building, or even to systems within a building.

Microgrid markets are markets based on time of delivery. Power is a resource whose value is determined by time of delivery. The information models for resource markets are already defined in OASIS. WS-Calendar defines a semantic model for M2M schedule negotiation services. EMIX (Energy Market Information Exchange) defines semantics for describing time-based products. (Energy Interoperation) defines eight services, each with just a few methods—the building blocks to construct markets in transactive energy.

Building markets is not enough without a means to create identities, to register contracts, and to settle transactions. The largest power markets, dealing with long-running purchases of centrally managed power, use traditional banking. Several projects are using expensive centrally authorized blockchain methods to operate microgrid-to-microgrid exchanges (see Brooklyn Microgrid Project, or the company Grid Singularity)

But to actually operate a microgrid, to balance power in real time, requires thousands of small transactions. To operate off-grid, or after grid failure, requires cryptocurrency that does not rely on permission from a server in the cloud. It must be local, and permissionless, and free. At the edges, transactive energy requires technology like the tangle-based IoTa. Individual transactions will be for a half cent or less. Systems must be able to establish identity and record contracts.

The Energy Mashup Lab is an open source project to create the software infrastructure for smart energy. The first step is to complete definition of the Common Transactive Services of smart energy. We are updating reference implementations of software to wrap a physical system and abstract its operation into power services. System developers will then be able to choose from the transactive agent personalities to match how their system acquires or disposes of power. All software will be available for download under an Apache 2.0 License.

Working, interoperable sets of code will be periodically donated to the various IoT framework consortia. For example, the AllSeen Alliance will want to modify code to support its own message formats and security profiles. Specific implementations will include ledger integration, i.e., IoTa or other cryptocurrency. Eventually, working profiles will move to microcode, and from microcode to ASICs. A system or application that supports a given framework and ledger will be able to discover the local micromarket, and self-integrate into the local microgrid.

The End of Net Metering

Net metering can never be more than a fantasy that dissolves once the level of distributed power generation rises beyond the level of noise. This is as true as water is wet.

If any neighborhood were all generating, all houses would produce more than they need at the same time. The only “target” for the power would be a use different than the houses, which means somewhere else. The distribution infrastructure must be in place to get there.

Assuming you could solve the physical problem of power transport, you are still left with the market problem. Each house wants to sell power at the same time as all the others do. In any realistic scenario that must reduce price.

This problem is dealt with today by enabling the [Utility] to disable the inverter to support system stability. This means that as the owner of home solar, a third party can decide whether you come to market, and what price you must take. By any economic definition, this means you do not own your solar power system.

Distribution itself brings other problems. Maintenance of the network is expensive. An actual net zero house is free-riding on all others. Middle income power hobbyists are subsidized by the poor. Transporting power is like driving a pickup truck filled with water, there is always splashing (line loss) and the further you travel, the less is left at the end.

The best place to use distributed generation is where you generate it, with no line loss, and no restriction on your use. The second best use is to store it, for later use on site. The third best use is to sell it when it fits your needs and you receive a price you accept. Perhaps the price you receive is from your neighbor. Perhaps you must discount your price because your customer is far away and much of your “product” is lost.  Home (and business) storage is an essential part of this.

It is inevitable that charges for the distribution network will eventually be unbundled from power. Per-kWh prices will drop. We must continue to innovate so that distributed generation and distributed storage fit within those future prices when the time is ripe.

For widely deployed distributed energy to work, we must adopt business models that encourage full use of all the power generated at the edges. To use power at the edges, we must manage power at the edges, and this includes power storage at the edges. It will require shared signals of scarcity and abundance within homes and commercial buildings, and between those homes and commercial buildings.

The supply of distributed energy varies over time and that supply is always local. Local usage is inherently more volatile than usage combined and averaged over a wide area. Local supply and local demand for power must be solved locally, with local transactive integration of systems.