Ohio’s solar market benefits from a statewide net metering mandate and a functional SREC market tied to the RPS. AEP Ohio (Columbus) and FirstEnergy (Cleveland) are the two largest utilities, each with established residential solar interconnection processes.
Ohio Solar Snapshot
NEC Edition: 2020 | Primary Utilities: AEP Ohio (Columbus), FirstEnergy (Cleveland/NE Ohio), DP&L/AES Ohio (Dayton) | Net Metering: Mandatory (retail rate, 10 kW residential cap) | SREC Market: Open market via PJM-GATS | Federal ITC: 30% residential / up to 50% commercial
SurgePV’s solar design suite helps automate compliance documentation.
NEC 2020 in Ohio
Ohio adopted NEC 2020 statewide. Key compliance points for Ohio solar:
| NEC Section | Requirement | Ohio Notes |
|---|---|---|
| 690.7 | 600V residential / 1000V commercial | Standard |
| 690.8 | 125% conductor sizing + temp derating | Cleveland: effective 56°C (0.76 factor); Columbus: 58°C (0.71 factor) |
| 690.9 | DC-rated OCPDs | Standard |
| 690.12 | Rapid shutdown | Required statewide |
| 690.31 | PV Wire/USE-2 or conduit | Standard |
| 690.41 | Grounding | Standard |
Ohio Climate — Conductor Derating
Ohio cities have moderate summer temperatures requiring standard derating:
| City | Max Air Temp | Effective Temp | THWN-2 Factor |
|---|---|---|---|
| Columbus | 36°C | 58°C | 0.71 |
| Cleveland | 34°C | 56°C | 0.76 |
| Cincinnati | 36°C | 58°C | 0.71 |
| Toledo | 34°C | 56°C | 0.76 |
Cold-Climate String Voltage (NEC 690.7)
Ohio has cold winters requiring NEC 690.7 minimum temperature correction:
| City | ASHRAE T_min | Voc Correction Factor (β = -0.30%/°C) |
|---|---|---|
| Cleveland | -18°C | 1.129 |
| Columbus | -18°C | 1.129 |
| Cincinnati | -15°C | 1.120 |
For a module with Voc = 45.0V in Columbus:
Factor = 1 + (-18 - 25) × (-0.003) = 1.129
Corrected Voc = 45.0 × 1.129 = 50.8V
Max modules (600V) = 600 ÷ 50.8 = 11.8 → 11 modulesAEP Ohio Interconnection
AEP Ohio serves Columbus, Chillicothe, Marietta, and most of central/southeastern Ohio:
| System Size | Process | Timeline |
|---|---|---|
| Under 10 kW | Small Generator Facility | 15–30 business days |
| 10 kW–5 MW | Level 1 study | 45–90 days |
| Over 5 MW | Level 2 study | 6–18 months |
Application requirements:
- Online application through AEP Ohio portal
- One-line diagram, site plan
- Equipment specifications
- Interconnection application fee (~$50–100 residential)
FirstEnergy Interconnection
FirstEnergy serves Cleveland, Akron, Youngstown, Sandusky, and northeastern Ohio (Ohio Edison subsidiary):
| System Size | Process | Timeline |
|---|---|---|
| Under 20 kW | Simplified | 15–25 business days |
| 20 kW–2 MW | Level 1 study | 45–90 days |
FirstEnergy’s simplified interconnection process uses the PJM Interconnection standards framework.
Ohio SREC Market
Ohio’s SREC market operates through PJM-GATS (the regional grid operator’s attribute tracking system):
How Ohio SRECs Work
- Solar system registered with PJM-GATS
- System generates electricity → GATS issues SRECs (1 SREC per MWh)
- SRECs listed on open market through brokers (SRECTrade, FlexiblePower, Sol Systems)
- Ohio utilities purchase SRECs to meet the Renewable Portfolio Standard solar carve-out
- Spot market prices fluctuate based on supply and RPS compliance deadlines
Current Market Context
Ohio’s SREC market has historically been less valuable than NJ or MA due to:
- RPS solar carve-out is a smaller percentage of total electricity
- More flexible compliance mechanisms for utilities
- Prices typically range from $3–$20/SREC vs. $200+ in New Jersey
For Ohio solar projects, SRECs provide incremental revenue but are not the primary financial driver — the federal ITC and net metering economics are more significant.
Ohio SREC Aggregation
For residential and small commercial systems generating a few SRECs per year, direct market access may not be efficient. SREC aggregators (SRECTrade, Flett Exchange) consolidate SRECs from multiple small systems and manage the sale process, paying the system owner a portion of the market price. This is often the practical choice for Ohio residential solar owners.
Ohio Net Metering
| Parameter | Details |
|---|---|
| Eligible size | Residential: up to 10 kW; Commercial: up to 100 kW |
| Credit rate | Full retail rate |
| Monthly carryover | Yes |
| Annual excess | Paid at wholesale market rate |
| Utilities covered | Investor-owned utilities (AEP Ohio, FirstEnergy, AES Ohio, DP&L) |
Ohio’s 10 kW residential cap is lower than many states. Systems between 10 kW and 100 kW can use net metering under the commercial category.
Municipal utilities (AMP Ohio members) may have different net metering policies — contact the specific municipal utility.
Columbus AHJ
Columbus Building and Zoning Services
- Building permit required for all solar installations
- SolarAPP+ participating for residential under 15 kW
- Electrical inspections through Columbus Division of Fire (CFD)
Cleveland
- City of Cleveland Building and Housing Department
- Electrical permit through Cleveland Building Department
- SolarAPP+ participation: confirm current status
Generate Ohio Solar Permit Packages
SurgePV generates NEC 2020-compliant permit packages for Ohio — formatted for AEP Ohio and FirstEnergy interconnection, with NEC 690 calculations and SolarAPP+-compatible documentation for Columbus and Cleveland.
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Frequently Asked Questions
What NEC edition does Ohio use?
NEC 2020 statewide. Some local Ohio jurisdictions may have locally adopted different editions — confirm with the specific building department.
How does the Ohio SREC market work?
Ohio SRECs are issued by PJM-GATS (one SREC per MWh). Systems sell SRECs on the open market through brokers. Ohio SREC prices are historically lower and more volatile than NJ or MA due to a less stringent RPS solar carve-out.
What is Ohio’s net metering residential cap?
10 kW for residential systems. Commercial systems up to 100 kW. Annual excess credits are paid at the wholesale rate — not forfeited.
