New Castle County Solar Permit Guide
Delmarva Power (an Exelon company) territory · New Castle County
Overview
GridPermit collects Delaware residential solar and permitting facts directly from official sources (city, county, and state government sites, utilities, and public utilities commissions) and shows only what we can verify, with a confidence score and a link to where it came from. Nothing here is estimated or inferred beyond what's stated below. See our methodology for the rules this page follows.
Permit timeline
Not yet verified.
Delmarva Power's own 'Connecting Your System to the Grid' page states: 'This complete interconnection process takes approximately 77 business days.' This figure covers Delmarva Power's own interconnection process end-to-end (application, installation, inspection, net meter installation) — it is a utility interconnection timeline, not the County's own building-permit review timeline, which was not separately found this session.
Battery/solar incentive program on record
No battery/storage incentive program is on record for this locality.
Permit fees
Not yet verified.
Rebates
Green Energy Program (GEP) — Residential Photovoltaic Grant
Statewide Delaware rebate open only to Delmarva Power and Light (DPL) customers, funded via a public benefits fund charge ($0.000356/kWh consumed): $0.80/watt for residential PV systems up to 50,000 watts, maximum grant $10,000, per DNREC's own rate table effective July 1, 2026. No grant may exceed 50% of total project cost, and total project cost must be $6.00/watt or less to qualify (cost cap). A Solar Shade Analysis with a Total Solar Resource Fraction (TSRF) of 70% or greater is required. Applications must be submitted within 12 months of installation completion. Applicants must sign over their Solar Renewable Energy Credits (SRECs) to the Delaware Sustainable Energy Utility as part of the grant application. Delaware's other utilities (Delaware Electric Cooperative, Delaware Municipal Electric Corporation) run separate, similar programs not detailed here since this record is scoped to Delmarva territory.
Status on file: active. Verify current status before relying on this.
Utility and generation supplier
Utility
Delmarva Power (an Exelon company)
Generation supplier
Delmarva Power (an Exelon company) (utility)
No Community Choice Aggregator was found serving Delaware this session; Delmarva Power is recorded as both the distribution and default generation utility.
Interconnection
Delmarva Power's own interconnection page, directly verified this session. For Level 1 (10kW AC inverter nameplate capacity or less — the typical residential rooftop solar case), the interconnection application fee is explicitly stated as 'No fee.' This is a statewide, utility-wide fact applicable to every Delmarva Power-territory Delaware locality, not county-specific.
Required documents
Not yet verified.
Inspection steps
- Within five days of starting work under a Delaware Homeowners electrical permit, contact one of the Delaware-licensed Inspection Agencies to have the electrical work inspected
- Before installing drywall, contact a Delaware-licensed Inspection Agency for a 'rough-in' inspection
New Castle County itself does not permit or inspect electrical work — per the County's own site, 'State of Delaware licensed electricians are required to have their electrical work inspected by a licensed Inspection Agency,' a state-level (not county-level) system. This describes the statewide homeowner-permit electrical inspection process (Delaware Division of Professional Regulation), not a County-specific building-permit inspection sequence, which was not separately confirmed this session.
Eligibility constraints
- Property types: residential
- Max system size (AC): 10 kW
- Max system size (DC): Not yet verified.
- Max thermal capacity: Not yet verified.
- Program/pathway: Delmarva Power Level 1 Interconnection (inverter-based, 10kW AC nameplate capacity or less)
- Other conditions:
- Level 1 is for lab-certified inverter-based small generator facilities of 10kW AC or less — the typical single-family residential rooftop solar case
- Larger or non-inverter-based systems require a higher interconnection level (2, 3, or 4) with an associated application fee
Official contacts
- New Castle County Department of Land Use, Permits & Inspections, official website
Need a solar installer who handles permits in New Castle County?
EnergySage is an independent solar marketplace where you can request property-specific pricing from installers familiar with local permitting.
Compare quotes from solar installers →You'll continue on EnergySage's website. GridPermit has a partner relationship with EnergySage; this link is not currently tracked, and whether the partnership results in compensation to GridPermit has not yet been confirmed.
Sources
- Connecting Your System to the Grid, Delmarva Power (an Exelon company) (utility). Accessed 2026-08-12.
- Permits & Inspections, New Castle County, Delaware (government). Accessed 2026-08-12.
- Green Energy Program Incentives (rate sheet, effective July 1, 2026), Delaware DNREC, Division of Climate, Coastal and Energy (program_administrator). Accessed 2026-08-13.
- Homeowner Electrical Permit, Delaware Division of Professional Regulation (government). Accessed 2026-08-14.
Frequently Asked Questions
What utility serves solar customers in New Castle County, Delaware?
Delmarva Power (an Exelon company) is the interconnection and distribution utility for New Castle County. The default electricity generation supplier is Delmarva Power (an Exelon company), a utility, separate from Delmarva Power (an Exelon company).
How long does a residential solar permit take in New Castle County?
Delmarva Power's own 'Connecting Your System to the Grid' page states: 'This complete interconnection process takes approximately 77 business days.' This figure covers Delmarva Power's own interconnection process end-to-end (application, installation, inspection, net meter installation) — it is a utility interconnection timeline, not the County's own building-permit review timeline, which was not separately found this session.
Who do I contact about solar permits in New Castle County?
New Castle County Department of Land Use, Permits & Inspections.