Domain Categories

Overview

In Bazefield, Domain Categories provide a high-level classification that groups asset types based on their role within a renewable power system. These categories describe the technological domain or system function an asset belongs to — such as energy generation, energy storage, grid integration, or meteorological measurement. They are specifically used to help organize asset types by generalized use case.

Bazefield Domain Categories

The table below summarizes the majority of the key domain categories used for power plant modelling and asset type classification.

Domain Category	Description
Wind	Covers everything related to wind turbines — including towers, blades, nacelles, and the systems that convert wind into electrical energy.
PV Solar	Includes all components in a solar plant that process sunlight into electricity, such as PV inverters, DC combiners, and string monitoring systems.
Hydro	Equipment used in hydroelectric generation — including turbines, penstocks, gates, valves, and flow control systems.
Energy Storage	Represents battery systems and related infrastructure used to store and discharge energy, including battery racks, PCS units, and BMS devices.
Balance of Plant	Shared infrastructure that supports generation and operations — like feeders, transformers, switchgear, and plant controllers. Not specific to one generation type.
Grid	Assets that interface with the external grid — such as point-of-interconnection meters, switchyards, and revenue metering equipment.
Meteorological	Weather and environmental monitoring equipment — including wind met towers, solar weather stations, and non-obstructive measurement assets such as SODAR, LIDAR, and Weather Forecast virtual assets.

Organization of Asset Types within Domain Categories

The image below illustrates how assets across multiple domain categories (Energy Storage, PV Solar, Wind, and Hydro) contribute to various power functions in a renewable plant — grouped into logical functional layers:

1. Resource Layer

Each generation domain is driven by a unique fuel or natural resource:

Wind and Water: Kinetic energy from air or fluid flow
PV Solar: Irradiance (sunlight)
Energy Storage: Stored electrical energy, originally derived from other sources

These resources are foundational to how assets are classified in Bazefield. Asset types related to the resource are typically classified in the Meteorological domain category, as they are responsible for measuring ambient and weather conditions that drive the amount of natural resource available for conversion.

Energy Storage	PV Solar	Wind	Hydro
N/A	Weather Station A collection of measurement equipment co-located and placed in different portions of the plant to directly measure the ambient conditions that directly affect the DC generation of the PV arrays. Weather Satellite A virtual asset type to organize satellite-driven data of irradiance (current, past, and future). This can help augment physical weather station telemetry or replace it altogether for resource assessments. Soiling Station A measurement station with 2 identical PV modules (one clean, one soiled) to quantify how much performance is being lost due to soiling.	Met Mast Collection of measurement equipment mounted on a common tower to measure the ambient conditions at different heights that govern turbine power production. SODAR Remote, non-intrusive measurement technology to measure wind speed, direction, and turbulence inside or near wind plants. Uses the reflection of sound waves of moving air particles for measurement purposes. LIDAR Remote, non-intrusive measurement technology to measure wind speed, direction, and turbulence. Uses the principle of light scattering from air particles and can be ground-mounted or turbine-mounted.	N/A

Energy Storage

PV Solar

Wind

Hydro

N/A

Weather Station

A collection of measurement equipment co-located and placed in different portions of the plant to directly measure the ambient conditions that directly affect the DC generation of the PV arrays.

Weather Satellite

A virtual asset type to organize satellite-driven data of irradiance (current, past, and future). This can help augment physical weather station telemetry or replace it altogether for resource assessments.

Soiling Station

A measurement station with 2 identical PV modules (one clean, one soiled) to quantify how much performance is being lost due to soiling.

Met Mast

Collection of measurement equipment mounted on a common tower to measure the ambient conditions at different heights that govern turbine power production.

SODAR

Remote, non-intrusive measurement technology to measure wind speed, direction, and turbulence inside or near wind plants. Uses the reflection of sound waves of moving air particles for measurement purposes.

LIDAR

Remote, non-intrusive measurement technology to measure wind speed, direction, and turbulence. Uses the principle of light scattering from air particles and can be ground-mounted or turbine-mounted.

N/A

2. DC Power Layer

Some domains (e.g., PV and Storage) begin with DC electricity, requiring:

DC Power Generation: Inverters, batteries, or solar panels that generate DC energy
DC Power Collection: Aggregates and routes DC output to conversion systems
DC Control: Manages the flow and performance of DC systems

This layer is most relevant for PV Solar and Energy Storage domains. Generic electrical equipment in the DC Power Collection subgroup, however, is most readily modelled in the Balance of Plant category

	Energy Storage	PV Solar	Wind	Hydro
DC Power Generation and Storage	Battery Module Pre-assembled collection of battery cells packaged together with mechanical support for mounting. Battery Rack Physical structure that organizes and supports several battery modules (typically 8–24). Battery Container Enclosure (10–40ft) that houses battery racks and auxiliary systems.	Photovoltaic (PV) Module* Pre-assembled collection of PV cells packaged with mechanical support for mounting (e.g., a solar panel). Photovoltaic (PV) Array or String* Panels connected in series to reach target voltage, on same rack and tied to tracker hardware.	N/A	N/A
DC Power Collection	DC String Logical/physical grouping of modules connected in series/parallel to form a high-voltage DC circuit. DC Bus Node that aggregates the output of one or more strings before the AC power conversion unit.	DC Combiner Aggregates multiple strings (typically 8–32) into a single DC output. DC Bus** Aggregates combiner output before feeding into the inverter or conversion unit.	N/A	N/A
DC Control	While Battery Management Systems exist for DC control, they are typically integrated through the AC Layer. DC Level data should be associated with the physical asset types above instead of any control asset directly.	Tracker Control Unit Control group of several individual motorized tracker units for closed loop feedback control of the angular positioning of a PV array Tracker Unit Individually motor-controlled unit which controls the angular positioning of a strin gof PV modules	N/A	N/A

Energy Storage

PV Solar

Wind

Hydro

DC Power Generation and Storage

Battery Module

Pre-assembled collection of battery cells packaged together with mechanical support for mounting.

Battery Rack

Physical structure that organizes and supports several battery modules (typically 8–24).

Battery Container

Enclosure (10–40ft) that houses battery racks and auxiliary systems.

Photovoltaic (PV) Module*

Pre-assembled collection of PV cells packaged with mechanical support for mounting (e.g., a solar panel).

Photovoltaic (PV) Array or String*

Panels connected in series to reach target voltage, on same rack and tied to tracker hardware.

N/A

DC Power Collection

DC String**

Logical/physical grouping of modules connected in series/parallel to form a high-voltage DC circuit.

DC Bus**

Node that aggregates the output of one or more strings before the AC power conversion unit.

DC Combiner

Aggregates multiple strings (typically 8–32) into a single DC output.

DC Bus**

Aggregates combiner output before feeding into the inverter or conversion unit.

N/A

DC Control

While Battery Management Systems exist for DC control, they are typically integrated through the AC Layer. DC Level data should be associated with the physical asset types above instead of any control asset directly.

Tracker Control Unit

Control group of several individual motorized tracker units for closed loop feedback control of the angular positioning of a PV array

Tracker Unit

Individually motor-controlled unit which controls the angular positioning of a strin gof PV modules

N/A

*While these asset types exist in reality, utility scale PV typically only provides DC aggregated level data on a DC recombiner or inverter level. Therefore these are not directly supported as asset types in the system.

**Modelled as part of the Balance of Plant Category for simplicity, and available for storage or PV sites

3. AC Power Layer

The AC Power Layer represents the infrastructure and systems that handle AC electrical power within a power plant—either by generating it directly or by converting it from DC power. This layer also includes the components that collect, manage, and control the flow of AC power to the grid.

AC Power Conversion
The primary unit responsible for either directly generating AC electrical power or converting previously generated DC power to AC power for integration with the grid.
AC Power Collection
Auxiliary electrical equipment that receives, aggregates, manages, and delivers AC electrical power from the AC power conversion units to the centralized plant substation in a safe and reliable manner. A chief process of the AC collection system is the step up (or down for storage sites) of electrical power from medium to high voltage or vice-versa. These all contribute to the Balance of Plant domain category.
Energy Management
A centralized supervisory control system which receives real-time conditions of all or most underlying power conversion units, and constraints from the local grid or electricity market to optimally manage the electrical output of all power conversion units in the plant.
Interconnection
High-voltage electrical infrastructure, and metering in the plant substation that aid in the final transmission of AC power to the external electric grid.

	Energy Storage	PV Solar	Wind	Hydro
AC Power Conversion	Battery Inverter Module A sub-component of an inverter that performs partial DC to AC conversion, often stacked in parallel with 2–4 other modules to allow for redundancy and scalability. Power Conversion System An electrical system that converts AC power to DC power during charging cycles, and vice-versa for discharging cycles. This can be a single inverter hooked up to DC side assets, or an integrated, enclosed system (e.g., Tesla Megapack).	PV Inverter Module A sub-component of an inverter that performs partial DC to AC conversion, stacked in parallel with others to scale. PV Inverter A central device that converts DC into AC to allow the power to be compatible with the grid. Inverters are typically fed by combiner boxes or DC strings. PV Inverter Station A larger containerized solution including one or more inverters and an associated transformer for step-up.	Wind Turbine Integrated electromechanical structure capable of directly converting the kinetic energy of the wind resource into AC power through a spinning rotor and synchronous generator.	Hydropower Generator Converts the kinetic energy of falling or flowing water into AC electricity using a turbine and generator system.
AC Power Collection	Power Transformer A piece of electrical equipment that steps up or down voltage levels during the power transmission process. Medium voltage transformers are typically co-located with the AC conversion units themselves to step up voltage for transmission to the substation (or vice-versa for storage systems). High voltage transformers perform the same function at the substation level. Collection Feeder A medium-voltage AC circuit that combines power from multiple distributed AC generators such as wind turbines, solar inverters, or ESS Units. Breaker An electromechanical switch that can interrupt current flow in a fault, overload, or manual disconnection event. Often upstream of collection feeders, but also in high voltage substation applications for plant protection. Disconnect Switch A manually or motor-operated device used to isolate sets of electrical equipment (e.g., AC Power conversion units) for maintenance, safety, or other purposes. AC Bus Shared electrical node that aggregates the output of several circuits or collection feeders and routes them between various other substation components, like transformers, breakers, and transmission lines Meter A device that measures and records electrical quantities such as energy (kWh), Power (kW), voltage, and current. Meters are typically both internal prior to the point of grid interconnection (e.g., an internal “check” meter), and at the point of interconnection itself for final utility billing and settlement data (a “revenue” meter) Capacitor Bank A passive group of capacitors connected to provide reactive power compensation to a power plant, which in turn improves the power factor and helps regulate voltage levels. Reactor Bank Group of inductors that control current flow or manage voltage levels, in part to absorb reactive power (opposite of a capacitor bank) Static Var Compensator An active, real-time voltage balancer in a high voltage system to dynamically control reactive power, regulate voltage and improve power factor. Control Building Secure building adjacent to the substation that houses critical SCADA systems for reliable operation of the plant.
Energy Management	Power Plant Controller A centralized system that monitors, coordinates, and commands multiple generation assets (e.g., AC Power Conversion units) based on real-time grid requirements, with focus on power production and voltage levels. It ensures regulatory compliance, optimizes performance, and responds to curtailment and dispatch signals.
Interconnection	Substation A facility at a power plant that serves as the primary interface between the internal electrical systems (e.g., the balance of plant) and the external grid. The substation houses all high-voltage electrical components to step up voltage, manage protection and switching, and enable safe, reliable interconnection with the external grid. A substation itself is typically the “parent” of all the underlying balance of plant assets described in the AC Power Collection functional class. Point of Interconnection (POI) The electrical boundary point where the power plant connects to the utility grid, located at the substation’s edge (sometimes the “switchyard”) on the high voltage side of the main power transformer(s). The actual asset that serves as the point of interconnection could be the high voltage bus connected to a utility transmission line, a grid-facing breaker, or the revenue meter. In general, the point of interconnection serves as a virtual reference point associated with revenue metering, grid compliance measurements (e.g. voltage, power factor), curtailment commands, and protection coordination. Scheduling Entity An organization responsible for submitting generation and consumption schedules to the grid operator or market authority. It often represents several power plants in a local region and ensures production aligns with grid requirements. The scheduling entity could be the plant owner and operator itself for merchant plants, a 3rd party organization, or the utility itself (for utility owned sites). In SCADA, it is often used to configure scheduling related data within the context of the scheduling entity. Switchyard The location at the high-voltage edge of the substation which connects or disconnects a power plant from the transmission system. Sometimes the Switchyard sits outside the substation and exists simply to route/switch power between transmission lines. Transmission Line High voltage power line that transmits large amounts of electrical energy long distances from power plants.