Node¶

Virtual balance points enforcing power conservation (Kirchhoff's law).

Configuration¶

Name¶

Unique identifier for this node within your HAEO configuration. Used to identify the node in connection endpoints.

Choose descriptive names based on electrical location: "Main Node", "AC Panel", "DC Bus", "Home Circuit"

Is Source¶

Whether this node can produce power (act as a power source). When true, the node can generate power that flows out through connections.

Default: false (node cannot produce power)

Available only when Advanced Mode is enabled.

Is Sink¶

Whether this node can consume power (act as a power sink). When true, the node can accept power that flows in through connections.

Default: false (node cannot consume power)

Available only when Advanced Mode is enabled.

Source and Sink Combinations¶

The combination of is_source and is_sink determines the node's behavior:

Pure Junction (is_source=false, is_sink=false - default):

• Power must balance: all power flowing in equals all power flowing out
• No power generation or consumption at the node itself
• Most common configuration for standard nodes
• Available in standard mode (Advanced Mode not required)

Source Only (is_source=true, is_sink=false):

• Node can produce power that flows out through connections
• Cannot accept power from connections
• Useful for modeling power sources without using dedicated generation or grid elements

Sink Only (is_source=false, is_sink=true):

• Node can accept power that flows in through connections
• Cannot produce power
• Useful for modeling power sinks without using dedicated consumption elements

Bidirectional (is_source=true, is_sink=true):

• Node can both produce and consume power
• Useful for modeling bidirectional power sources or flexible power exchange points
• Similar to bidirectional grid elements but without automatic connection creation

Purpose¶

Nodes are connection hubs where power balance is enforced:

Nodes are not physical devices - they represent electrical junctions where Kirchhoff's current law applies.

Use Cases¶

Single node (simple): Central hub for all elements.

graph LR
    Source1[Source] <--> Node[Switchboard]
    Source2[Source] --> Node
    Storage[Storage] <--> Node
    Node --> Sink[Sink]

    class Node emphasis

Most residential systems use the automatic switchboard node only. Additional nodes are not needed unless you have complex multi-bus topologies.

Multiple nodes (complex): Separate AC/DC or hierarchical distribution.

graph LR
    Source[Source] --> DC[DC Node]
    Storage[Storage] <--> DC
    DC<-->|Inverter|AC[AC Node]
    Bidirectional[Bidirectional] <--> AC
    AC-->Sink[Sink]

    class DC dc
    class AC ac

Hybrid inverter systems with separate buses.

Configuration Example¶

Simple node for connecting elements:

Then connect elements to "Main Node" via connections.

Input Entities¶

Each configuration option creates a corresponding input entity in Home Assistant. Input entities appear as Switch entities with the config entity category.

These switch inputs are only created when Advanced Mode is enabled. Input entities include a forecast attribute showing values for each optimization period. See the Input Entities developer guide for details on input entity behavior.

Sensors Created¶

Sensor Summary¶

A Node element creates 1 device in Home Assistant with the following sensors.

Power Balance¶

The marginal cost or value of power at this specific node in the network. See the Shadow Prices modeling guide for general shadow price concepts.

This shadow price represents the "local spot price" for energy at this connection point. It shows how much the total system cost would change if you could inject or extract 1 kW of power at this node.

Interpretation:

• Positive value: Represents the cost of power at this node
  • Higher values indicate expensive power (e.g., importing during peak prices)
  • Shows what you would save by reducing consumption or adding generation at this node
• Negative value: Represents surplus power at this node (uncommon)
  • Indicates more generation than consumption
  • Shows the value that could be captured by adding loads or storage at this node
• Differences between nodes: Reveal the economic value of power transfer between network locations
  • Larger differences indicate stronger incentive for power flow between nodes
  • Help identify valuable connection points in the network

Example: A value of 0.22 means power at this node costs $0.22 per kW at this time period, reflecting the marginal cost to supply this location in the network.

Note: For physical power measurements, monitor connected entity sensors instead. Nodes only provide shadow prices, not physical power flow data.

All sensors include a forecast attribute containing future optimized values for upcoming periods.

Troubleshooting¶

Infeasible optimization: Check all elements connected, sufficient sources exist, connection directions correct, limits not too restrictive.

Unexpected power flows: Verify connection endpoints, review node names unique, check connection min/max power limits.

Multiple Nodes¶

Use when:

• Physical separation (AC/DC buses in hybrid inverter systems)
• Intermediate limits (inverter capacity, feeder constraints)
• Hierarchical distribution (main panel and sub-panels)

Configuration: Enable Advanced Mode on your hub, then create additional node elements and link them with connections.

Complexity: Requires more configuration and adds more constraints, but accurately models real system architecture.

Hybrid Inverter Example¶

For hybrid (AC/DC) inverter systems, use separate AC and DC nodes with a connection between them:

graph LR
    Storage[Storage] <--> DC[DC Node]
    Source[Source] --> DC
    DC <-->|Inverter| AC[AC Node]
    Bidirectional[Bidirectional] <--> AC
    AC --> Sink[Sink]

The connection between DC and AC nodes represents the inverter. Set connection power limits to match the inverter rating.

See Connections for detailed configuration guidance.

Next Steps¶