Washington, DC has one of the strongest solar economics environments in the United States, driven by very high SREC prices in the DC market, aggressive city renewable energy policies, and a compact permit jurisdiction that keeps regulatory complexity relatively contained compared to sprawling metropolitan areas. But DC solar design has specific considerations: the DC Department of Buildings permit process, Pepco interconnection, DC's Solar for All program, historic preservation across large portions of the district, and unique jurisdictional considerations for federal properties within the city. This deep dive walks through each element for solar EPCs and installers.
Washington DC solar at a glance
- Permit authority: DC Department of Buildings (DOB) — issues construction and electrical permits for DC
- State/district building code: DC Construction Codes (based on ICC codes with DC amendments)
- Electrical code: NEC as adopted by DC; verify current enforced edition with DC DOB
- Utility: Pepco (Potomac Electric Power Company), an Exelon subsidiary
- SREC market: DC has one of the highest-value SREC markets in the US; SRECs are traded through PJM-EIS GATS
- DC solar policy: the DC Renewable Portfolio Standard drives strong SREC demand; the Solar for All program supports low-income solar deployment
- Historic preservation: extensive historic districts including Georgetown, Capitol Hill, Dupont Circle, Anacostia, and many others
DC's SREC market — the biggest economic driver
DC's Solar Renewable Energy Credit market has historically been one of the highest-value SREC markets in the United States, driven by the district's ambitious solar carve-out in its Renewable Portfolio Standard. For solar EPCs and installers:
- DC SREC prices meaningfully improve project economics compared to most other US markets
- SREC contracts (long-term commitments to sell SRECs at set prices) are a standard part of DC solar project financing
- DC SRECs are traded through PJM Environmental Information Services GATS platform
Solar EPCs new to DC need to build SREC contracting and registration into their project workflow from day one.
DC Department of Buildings permit process
The DC Department of Buildings handles construction and electrical permits for solar installations in DC. Solar projects typically require:
- A building permit for structural, roof loading, and attachment
- An electrical permit for the electrical scope
- PE stamping where required
- Fire department coordination where required
- Historic Preservation Review Board (HPRB) or Office of Planning historic preservation review for regulated buildings
DC DOB has evolved online permit filing systems. Always confirm the current filing workflow and forms with DC DOB before submitting.
Pepco interconnection process
Pepco is the electric distribution company for DC. Pepco's interconnection process for solar follows standardized workflows:
- Interconnection application submission with plan set, equipment specifications, and single-line diagram
- Pepco engineering technical review
- Interconnection agreement execution
- Installation
- Utility witness test and meter installation
- Permission to operate (PTO)
DC's net metering framework provides for retail-rate credit for exported solar, though specific mechanics should be verified with Pepco for the current tariff structure.
DC historic preservation review
DC has extensive historic preservation coverage, including designated historic districts and individually designated buildings across the district. Solar installations on regulated buildings require historic preservation review before DOB permits can be issued. Review evaluates:
- Visibility from the public way
- Impact on historic character and features
- Compatibility of installation approach with preservation guidelines
Plan sets for regulated buildings should be designed for the acceptable visibility envelope. Early engagement with preservation staff helps prevent extended review cycles. Georgetown, Capitol Hill, and other visible historic districts have particularly rigorous review.
Federal property jurisdictional considerations
Portions of DC contain federal properties (National Mall area buildings, federal facilities, etc.) with jurisdictional considerations that differ from standard DC permit processes. Solar work on federal properties may involve GSA (General Services Administration) processes, agency-specific requirements, and federal contracting rules. This is typically outside standard commercial solar EPC scope.
Common DC solar permit rejection reasons
- Historic preservation review not initiated for regulated buildings
- Structural analysis inadequate for older DC building stock
- Pepco SLD format not matching utility conventions
- PE stamping missing where required
- Fire code pathway and setback requirements not clearly documented
- SREC registration and contract documentation missing or misaligned
- Rapid shutdown boundary and initiation devices not correctly documented
DC solar timeline expectations (general)
- Design and PE stamping: 1-3 weeks for straightforward residential
- Historic preservation review (if applicable): weeks to several months depending on visibility
- DC DOB permit review: variable, weeks depending on complexity
- Pepco interconnection (residential): variable; verify current timelines with Pepco
- Commercial projects: extended timelines depending on system size and interconnection studies
Where outsourced solar design fits into the DC market
DC's combination of very strong solar economics, compact but complex permit environment, extensive historic preservation coverage, and Pepco interconnection creates a market where local expertise materially improves permit success and project economics. Solar EPCs and installers benefit from outsourced design partners who understand DC codes, Pepco formats, historic preservation coordination, and SREC contracting workflows.
RIH Engineering provides outsourced solar PV design for EPCs, installers, and developers operating in Washington, DC and the greater DMV metro. Our plan sets are prepared for DC DOB review, Pepco interconnection, and coordinated with historic preservation and SREC documentation requirements. If you want to talk through how outsourced design fits your DC pipeline, get in touch.
Frequently asked questions
Who issues solar permits in Washington, DC?
The DC Department of Buildings (DOB) issues construction and electrical permits for solar installations in the District of Columbia. Solar projects typically require both a building permit and an electrical permit, with PE stamping where required and historic preservation review for regulated buildings.
Which utility serves Washington, DC for solar interconnection?
Pepco (Potomac Electric Power Company), an Exelon subsidiary, is the electric distribution company for Washington, DC. All DC solar projects interconnect through Pepco's standardized interconnection process.
Why is the DC SREC market so valuable for solar?
DC's Solar Renewable Energy Credit market has historically been one of the highest-value SREC markets in the US, driven by the District's ambitious solar carve-out in its Renewable Portfolio Standard. DC SRECs meaningfully improve project economics and are typically contracted long-term as part of project financing.
How does historic preservation affect solar in DC?
DC has extensive historic preservation coverage including districts like Georgetown, Capitol Hill, and Dupont Circle plus individually designated buildings. Solar on regulated buildings requires historic preservation review before DOB permits are issued. Review evaluates visibility from the public way and impact on historic character.
Do DC solar projects require PE stamping?
Commercial and larger residential solar projects in DC generally require PE stamping. Smaller residential projects may not require PE stamping depending on system size. Always verify with DC DOB for the specific project size and building type.