Solar Panel Cost in Delaware (2026 Estimate)

BySunMetricLab Editorial Team·Independent solar research and calculators

Data last updated September 10, 2026 · ranks #29 of 50 states for modeled payback

Delaware averages about 4.4 peak sun hours a day (below the national average) with an approximate residential electricity rate near 15¢/kWh, in the mid-range nationally. In the model used here, an 8 kW system in Delaware produces roughly 10,280 kWh a year and trims about $1,500 off annual electricity costs, paying back its net cost in about 10.9 years. That is a middle-of-the-pack payback, so whether solar is worth it in Delaware often comes down to your specific rate, roof, and any state or utility incentives.

Estimated system cost and payback in Delaware

Costs assume roughly $3.00/watt installed for Delaware; the net column applies a 30% federal credit for comparison with quotes that include it. Savings and payback use the state's sun hours and rate above.

The 30% federal Residential Clean Energy Credit ended for systems paid for after December 31, 2025 under the 2025 federal budget law. Net-after-credit figures apply only if you still qualify (for example a 2025 expenditure, or a leased system where the installer passes a credit through). Confirm with a tax professional.

What moves the numbers in Delaware

Two inputs drive most of the difference between states: how much sun a system sees and what each offset kilowatt-hour is worth. Delaware's 4.4 sun hours set production, and its roughly 15¢/kWh rate sets what that production saves. The bigger unknowns are your roof, shading, and how your utility compensates exported power, since a lower export rate can pull real savings below the retail-rate figure above.

Net metering and export credits in Delaware

Delaware law requires Delmarva Power, the Delaware Electric Cooperative and the municipal utilities to offer retail-rate net metering to residential customers. Surplus kilowatt-hours in a given month carry forward as a credit on the next bill, and after twelve months a customer can ask to be paid out for any remaining balance at the utility's supply rate. Systems can be sized up to roughly 110 percent of the home's expected annual use, which leaves a little room for growth in consumption.

The three utility types handle the details differently, particularly around how the supply and delivery portions of the bill are credited and how excess is cashed out. The cooperative in particular has revised its policies for new solar members over the years, so anyone in Kent or Sussex County should ask for the current interconnection terms before signing.

Delaware solar incentives beyond the federal credit

Delaware's Green Energy Program, administered through the Department of Natural Resources and Environmental Control and funded by utility ratepayers, offers upfront grants for residential solar in Delmarva Power territory, with the cooperative and municipal utilities running their own smaller versions. Grant levels are set per watt with a per-project cap and have been adjusted downward as installation costs fell, so check the current schedule and whether funds are available for the year. Delaware has no sales tax and no state income tax credit for solar.

Solar renewable energy certificates are a second income stream: Delmarva runs an annual SREC procurement in which homeowners can bid to sell their certificates under long-term fixed-price contracts, and certificates can otherwise be sold on the PJM market. DNREC has also piloted low-income solar programs, and the Delaware Sustainable Energy Utility offers energy loans that can cover solar.

Utilities and rate plans in Delaware

Delmarva Power, an Exelon company, serves New Castle County and parts of Kent and Sussex, making it the state's largest provider; the Delaware Electric Cooperative serves most of the rural south, and nine municipal utilities including Dover, Newark, Milford and Lewes serve their own cities through the Delaware Municipal Electric Corporation. Delmarva's residential rate is a flat energy charge plus a customer charge, with generation supplied at a standard offer price that changes periodically. Retail prices sit somewhat above the national average, and with retail net metering intact the savings per kilowatt-hour are straightforward to estimate.