Solar Power System

This document provides an orientation to the solar power system. It explains the system’s major components, where they are located, and how they work together to generate electricity.

System Facts

• Total panels: 36
  • 24 panels — eastern end of the south-facing roof plane
  • 12 panels — east-facing roof plane above the garages
• Microinverters: Enphase (one per panel)
• Primary system hub: Enphase Gateway
• Controller location: exterior wall behind the Unit B garage
• Connectivity
  • Primary: local WiFi via nearby UniFi access point
  • Secondary / backup: built-in Cellular modem
• Local network segment: The Internet of Things (IOT) Virtual LAN (VLAN)
• Installer: ProTech Solar
• Utility provider: Duke Energy Service
• Utility meter type: bidirectional net meter used for Net-Zero Metering metering.

System Overview

The solar power system converts sunlight’s energy into electrical power for the home and, when excess power is generated, exports it to the electrical grid. Our account is credited for that power at the same per-kilowatt-hour rate as we pay for power coming into the home, hence “net zero”. If the solar power system produces more power in a month than we consume, we are charged nothing. If we produce less, we are charged for only the difference. In either case, we are charged $30/month for the connection to “the grid”, plus, of course, taxes, fees, service fees, and so on.

The system operates as a coordinated set of components:

1. Solar panels capture energy from sunlight.
2. Microinverters, one per panel, convert a panels Direct Current (DC) output into grid-compatible Alternating Current (AC) electricity.
3. Electricity flows into the home’s electrical system and through the Duke Energy Service electric meter.
4. If production exceeds demand, excess electricity flows outward through the utility meter and into the grid; we pay only for the difference.
5. System status and production data are reported through the Enphase monitoring platform. Our Home Assistant server captures that data so we can monitor the health of the system.

As mentioned, The system is interconnected with the electrical grid through a Duke Energy Service bidirectional power meter, which records both imported and exported electricity as part of a Net-Zero metering agreement.

Physical Installation

The solar power system consists of solar panels and inverters distributed across two roof planes, a controller box, and, of course, the wires and conduits that connect them.

• 24 panels are installed on the eastern section of the south-facing roof plane
• 12 panels are installed on the east-facing roof plane above the garages
• The Enphase Gateway/Controller is mounted outside on the wall behind the Unit B garage

Straw‑Man Physical Layout Diagram

flowchart TB

SouthRoof["East end of South-facing roof plane (24 panels)"]

EastRoof["East-facing garage roof plane (12 panels)"]

SouthRoof --> Gateway
EastRoof --> Gateway

Gateway["Enphase IQ Gateway
Exterior wall behind the unit B Garage"]

Major Components

Solar Panels

The system includes 36 photovoltaic panels mounted across two roof planes.

South-Facing Roof Plane

• 24 panels
• Located on the eastern portion of the south-facing roof

East-Facing Garage Roof Plane

• 12 panels
• Located on the roof above the garages

Microinverters

Each solar panel has an Enphase microinverter mounted beneath it.

The microinverter performs two primary functions:

• Converts electricity from DC to AC
• Reports production and operational status to the system Controller

Because every panel has its own microinverter, the system can measure the performance of individual panels.

Enphase Gateway/Controller

The central communications device for the system is the Enphase IQ Gateway.

Location

Mounted outside on the wall behind the Unit B garage.

Purpose

The controller:

• Collects production data from microinverters
• Communicates with the Enphase monitoring platform
• Enables diagnostics and alerts
• Allows installer support when needed

Power generation continues even if the controller is temporarily offline.

Utility Interconnection

The solar system is interconnected with the local electrical grid operated by Duke Energy Service.

Electricity produced by the solar panels flows first into the home’s electrical system.
If production exceeds consumption, excess electricity flows through the utility meter into the grid.

The system operates under Net-Zero Metering.

• Exported electricity is recorded by the meter.
• Imported electricity is also recorded.
• Billing reflects the net difference between the two.

Connectivity

The Controller maintains two communication paths.

Cellular Connection

Built‑in Cellular modem used for monitoring and service diagnostics.

Local Network Connection

Controller → nearby UniFi access point → home network

System Relationship Diagram

---
config:
  layout: fixed
---
flowchart TB
 subgraph Roof["Roof / Physical Installation"]
        A["A. South-facing roof plane 24 panels"]
        B["B. East-facing garage roof plane 12 panels"]
        C["C. Enphase Microinverters, One per panel"]
  end
 subgraph EG["Enphase IQ Gateway"]
        H["H. Cellular Radio"]
        I["I. WiFi IOT11449"]
  end
 subgraph Garage_back_wall["Garage B outside back wall"]
        E["E. Duke Energy Meter"]
        PVD["PV System Disconnect"]
        EG
  end
 subgraph Unit_A_Garage["Unit A Garage (inside)"]
        CBA["CBA. Unit A Circuit Breaker Panel"]
  end
 subgraph Unit_B_Garage["Unit B Garage (inside)"]
        CBB["CBB. Unit B Circuit Breaker Panel"]
  end
 subgraph HN["Home Network"]
        AP["WiFi Access Point (Unit A Garage)"]
        HA["Home Assistant"]
  end
 subgraph s1["Internet"]
        n1["ProTech Installer"]
        L["L. Enphase Monitoring Platform"]
  end
    HA -.-> L
    A --> C
    B --> C
    EG --> PVD
    E --> CBA & CBB
    I --> AP
    C --> EG
    PVD --> E
    n1 --> L
    H -.-> L
    HN --> s1

Orientation Summary

The solar power system is composed of equipment on the roof, electrical integration with the home and utility grid, and a controller that supports monitoring and diagnostics.

In simplified terms:

• Solar panels generate electricity.
• Microinverters convert panel output to usable AC power.
• Power flows into the home electrical system and through the Duke Energy Service net meter.
• Excess electricity is exported under Net-Zero.
• The Enphase Controller / Gateway supports monitoring and diagnostics.