Delaware PSC Net Metering and Delmarva Power: Interconnection Guide

Key Takeaways

• Residential solar systems connected to Delmarva Power (DP&L) are capped at 25 kW per meter (August 2026).
• Non-residential systems have a higher cap of 2 MW per meter (August 2026).
• Systems must be sized to produce no more than 110% of historical electrical consumption (August 2026).
• Excess kWh credits are valued at the sum of supply and distribution service charges (effective January 1, 2024).

What are the Delaware Net Metering Rules for Delmarva Power Customers?

Delaware's net energy metering regulations, primarily found in 26 DE Admin. Code 3012, govern how solar systems interconnect with Delmarva Power (DP&L) and how excess generation is handled. These rules define system sizing limits, credit valuation for surplus energy, and provisions for meter aggregation. Understanding these regulations is crucial for any solar project in the state.

The Delaware Public Service Commission (PSC) sets specific capacity limits for different customer types. Residential systems, for instance, must not exceed 25 kW per DP&L meter (August 2026). Non-residential systems have a cap of 2 MW per DP&L meter (August 2026), while farm customers are limited to 150 kW per DP&L meter (August 2026). These rules ensure that systems are appropriately sized for their intended use and do not overwhelm local grid infrastructure.

How Large Can Your Solar System Be in Delaware?

Delaware regulations impose strict limits on the size of solar systems eligible for net metering. These limits vary by customer type and are designed to align system generation with historical energy consumption.

For residential customers, a solar system "will not exceed 25 kW per DP&L meter" (August 2026). Non-residential customers can install larger systems, with a cap that "will not exceed 2 MW per DP&L meter" (August 2026). Farm customers, as defined in 3 Del.C. §902(3), face an intermediate limit, where their systems "will not exceed 150 kW per DP&L meter" (August 2026).

Beyond these absolute capacity limits, all net-metered systems in Delaware must adhere to a sizing limit based on historical usage. A system "is designed to produce no more than 110% of the host customer's expected aggregate electrical consumption" (August 2026). This calculation relies on "the average of the 2 previous 12-month periods of actual electrical usage" (August 2026). This ensures that systems are primarily for self-consumption rather than primarily for selling power back to the grid.

To estimate your potential system size based on your energy needs, you can use a solar sizing tool.

How Does Delmarva Power Credit Excess Solar Energy?

When your solar system generates more electricity than you consume, the excess energy is sent back to the grid and credited to your account. Delaware's regulations specify how these excess kilowatt-hour (kWh) credits are valued.

"Effective January 1, 2024, for both residential and non-residential customers, the monthly excess kWh credit shall be valued at the sum of the volumetric (kWh) components of the supply service charges and distribution service charges, not including the charges for societal benefits programs" (August 2026). This means you receive credit for both the energy itself and the cost of delivering it, excluding certain public program charges.

A significant provision mandates that "On or before December 1, 2026, excess kWh Credits at the end of an annualized billing period shall carry over to subsequent annualized billing periods" (August 2026). This ensures that any unused credits do not expire at the end of a year, providing long-term value for customer-generators.

Furthermore, the "customer shall retain ownership of all RECs associated with electric energy produced from all eligible energy resources of the customer-generator facility and consumed by the customer unless the customer has relinquished such ownership by contractual agreement" (August 2026). This means you generally keep the Renewable Energy Credits (RECs) generated by your system, which can have additional financial value.

Can You Aggregate Multiple Meters for Net Metering?

Delaware's regulations allow for meter aggregation under specific conditions, which can be beneficial for customers with multiple meters or accounts on contiguous properties. This is referred to as "Condition 2 Meter Aggregation."

Under this provision, "Customers with multiple meters or accounts may aggregate meters provided the facility produces no more than 110% of aggregate consumption" (August 2026). To utilize this, customers must file "a ranked meter list with DP&L at least 90 days before construction" (August 2026). This process allows a single solar system to offset consumption across several meters, optimizing the benefits of net metering for larger properties or complexes.

What About Grid-Integrated Electric Vehicles and Meter Costs?

Delaware's net metering framework also addresses emerging technologies like grid-integrated electric vehicles (EVs) and sets limits on customer costs for metering equipment.

For EVs, "A retail electric customer having on its premises 1 or more grid-integrated electric vehicles shall be credited in kilowatt-hours (kWh) for energy discharged to the grid from the grid-integrated electric vehicle's battery at the same kWh rate that customer pays to charge the battery from the grid" (August 2026). This provision supports vehicle-to-grid (V2G) technology by ensuring fair compensation for energy supplied back to the grid from an EV.

Regarding metering equipment, "Residential customers shall not be responsible for paying more than $200 toward the reasonable cost of any new, replacement, or modified meter or meters installed for net-metering purposes" (August 2026). This cap protects residential customers from excessive charges for necessary meter upgrades. Additionally, "EDCs must evaluate and approve qualifying meter collar adapter models within 90 days for supply-side PV, BESS, and EV charger interconnection" (August 2026), streamlining the approval process for new interconnection technologies.

How We Verified Delaware's Net Metering Regulations

We reviewed the official Delaware Public Service Commission (PSC) regulations under 26 DE Admin. Code 3012 on August 23, 2026. All figures and provisions cited in this guide are directly sourced from the official state administrative code, accessed via the provided URL. We do not extrapolate or invent any details beyond what is explicitly stated in the regulatory document.

Understanding Delmarva Power Interconnection: What You Need to Know

Navigating the regulatory landscape for solar interconnection in Delaware requires careful attention to detail. While the rules provide a clear framework, certain aspects and limitations are important to recognize.

The state's net metering program has an aggregate cap: "If the total generating capacity, measured in megawatts (MW) of alternating current (AC), of all customer-generation using net metering systems served by an electric utility exceeds 8.0% of the capacity necessary to meet the EDC's average Delaware transmission peak demand for the preceding 3 years, the EDC may elect not to provide net metering services to additional customers" (August 2026). This means there is a theoretical limit to how much net-metered solar can be deployed before the utility can refuse new applications. While this cap is typically far off, it represents a long-term consideration for the program's availability.

It is also important to note what these regulations do not cover. For instance, "Standalone commercial community solar projects are governed under separate 26 DE Admin. Code 3013 regulations" (August 2026). This guide focuses specifically on customer-generator net metering under 3012. Additionally, "Systems exceeding 2 MW require PJM wholesale queue interconnection" (August 2026), indicating that very large projects fall under a different set of wholesale market rules rather than the retail net metering framework.

Understanding these specific provisions and their limitations is key to a successful solar project in Delaware. For context on similar regulatory environments, you may find our guides on Maryland PSC net metering rules, Pennsylvania PUC Chapter 75 net metering, and New Jersey BPU Solar Act helpful.