Appalachian Power Solar Interconnection in Virginia
Appalachian Power Company (APCo), a subsidiary of American Electric Power (AEP), serves approximately 520,000 customers across southwestern Virginia, operating a distinct interconnection framework that differs in meaningful ways from Dominion Energy's process in the eastern part of the state. This page covers how APCo's solar interconnection process works, the regulatory bodies that govern it, the common project scenarios applicants encounter, and the technical and procedural boundaries that determine which pathway a given system must follow. Understanding APCo's requirements is essential for any residential, commercial, or agricultural solar project in Virginia's APCo service territory.
Definition and scope
Appalachian Power's solar interconnection process is the formal technical and administrative procedure by which a customer-owned generation system — such as a rooftop photovoltaic array or ground-mounted solar installation — is evaluated, approved, and physically connected to APCo's distribution grid. The process is governed at the federal level by FERC Order 2003 for larger generators and at the state level by the Virginia State Corporation Commission (SCC), which oversees retail interconnection standards under Virginia Code §56-594 and related SCC rulings.
APCo administers its interconnection rules under its filed tariff, which is publicly available through AEP's service territory documentation and the FERC electronic tariff database. The SCC's net metering rules, codified under 20 VAC 20-315, establish the baseline interconnection rights for systems up to 1 megawatt (MW) for residential and small commercial customers, and up to 3 MW for other customer classes under 2020 amendments tied to the Virginia Clean Economy Act.
Scope of this page: This page applies exclusively to projects within APCo's Virginia service territory, which covers primarily the southwestern counties including Montgomery, Roanoke, Pulaski, Wythe, Smyth, and adjacent areas. Projects in Dominion Energy Virginia's service territory follow a separate interconnection framework covered at Dominion Energy Solar Interconnection in Virginia. Federal-jurisdiction projects (those connecting at transmission voltage above distribution level) fall under FERC jurisdiction and are not covered here. Out-of-state portions of APCo's service area (West Virginia, Tennessee) are outside the scope of Virginia SCC authority and are not addressed.
How it works
APCo's interconnection process for distributed solar follows a structured sequence of phases aligned with SCC and FERC requirements. The process differs by system size and complexity, with two primary tracks:
Level 1 (Simplified/Expedited) — Systems ≤25 kW AC
Residential rooftop and small ground-mount systems below 25 kilowatts alternating current (kW AC) typically qualify for an expedited review.
Level 2 (Standard Review) — Systems 25 kW to 500 kW AC
Mid-scale commercial, agricultural, and community solar projects in this range require a standard interconnection study, which includes a detailed technical review of impact on the local distribution circuit.
Level 3 and above — Systems >500 kW AC
Larger projects trigger full interconnection studies, including potentially a system impact study and facilities study, with timelines negotiated under tariff provisions.
The numbered phases common to all tracks are:
- Pre-application inquiry — Applicant requests available hosting capacity data for the relevant distribution feeder.
- Application submission — Applicant files APCo's interconnection application form, single-line diagram, and site plan, along with the applicable fee.
- Completeness review — APCo has 10 business days to determine whether the application is complete.
- Technical feasibility study — APCo evaluates whether the system can interconnect without adverse impact on power quality, voltage regulation, or protection coordination.
- Interconnection agreement execution — Upon study approval, both parties execute a formal interconnection agreement specifying metering, protection relay requirements, and inspection obligations.
- Inspection and permission to operate — APCo conducts or coordinates a physical inspection, and the local authority having jurisdiction (AHJ) must also approve the installation under the Virginia Uniform Statewide Building Code (USBC). Permission to operate (PTO) is issued only after both APCo and the AHJ have signed off.
For a broader understanding of how solar systems interface with Virginia's grid infrastructure, the conceptual overview of Virginia solar energy systems provides foundational context.
Common scenarios
Residential rooftop systems (5–12 kW AC): The most common application in APCo territory. These systems almost always qualify for Level 1 review. The primary technical requirement is an inverter that meets UL 1741 and IEEE 1547-2018 anti-islanding standards.
Agricultural and ground-mount systems (50–250 kW AC): Common in southwestern Virginia's rural counties. These typically enter Level 2 review and may require APCo to upgrade or reconfigure protection equipment on the feeder, with upgrade costs allocated to the interconnecting customer under tariff rules.
Community solar projects: Virginia's community solar framework, expanded under Code of Virginia §56-585.1:11, allows aggregated subscriber participation. APCo community solar projects in the 500 kW–5 MW range require full interconnection studies. More detail on community solar structures is available at community solar programs in Virginia.
Battery storage additions: When solar energy storage is added to an existing interconnected solar system, APCo requires a modification to the existing interconnection agreement and a supplemental technical review for combined AC output capacity.
Decision boundaries
The central technical decision point in APCo's process is whether a proposed system triggers an adverse impact on the distribution circuit — specifically voltage deviation beyond ±5% of nominal, protection miscoordination, or reverse power flow that exceeds feeder capacity.
Key boundary thresholds to understand:
| System Size | Review Track | Typical Timeline | Study Fee Required |
|---|---|---|---|
| ≤25 kW AC | Level 1 (Expedited) | 15 business days | Minimal or none |
| 25–500 kW AC | Level 2 (Standard) | 45–90 business days | Yes |
| >500 kW AC | Level 3+ (Full Study) | 6–18 months | Yes, escalating |
Grid-tied vs. export-limited systems: A system configured to export zero net power to the grid (export-limited via inverter programming or external disconnect) may qualify for a simplified interconnection path even at larger sizes. This distinction — between export-limited and full-export configurations — is one of the most significant design-phase decisions affecting APCo interconnection timelines and cost.
Net metering eligibility boundary: As of SCC Order PUR-2021-00142, APCo customers in Virginia are eligible for net metering up to the system size caps established by SCC rules. Systems exceeding the applicable cap may interconnect but cannot receive net metering credits at full retail rate. The regulatory context for Virginia solar energy systems page details the SCC orders governing these caps.
Permitting parallel track: APCo's interconnection approval and local building permit approval run on parallel, not sequential, tracks. A project cannot receive APCo's permission to operate without both the APCo interconnection agreement execution and the local AHJ electrical inspection passing. In Montgomery County and Roanoke County — two of APCo's most active Virginia solar markets — local building departments follow the USBC 2021 edition, which incorporates NFPA 70 (National Electrical Code) 2023 requirements including NEC Article 690 for photovoltaic systems.
The Virginia solar authority home provides entry-point orientation to all major topics across the state's solar regulatory and technical landscape.
References
- Virginia State Corporation Commission (SCC) — Net Metering
- 20 VAC 20-315 — Virginia SCC Net Metering Rules
- Code of Virginia §56-594 — Net Energy Metering
- Code of Virginia §56-585.1:11 — Community Solar
- FERC Order 2003 — Small Generator Interconnection Procedures
- AEP / Appalachian Power — Distributed Generation Interconnection
- Virginia Department of Housing and Community Development — Uniform Statewide Building Code (USBC)
- [IEEE 1