Solar in Delaware

Delaware's net metering is established under Public Service Commission rules and codified in state law, crediting exported energy from systems up to 25 kW at the full retail rate with an annual true-up. This statutory foundation makes it more durable than a pure commission-rule framework. Delmarva Power, the dominant investor-owned utility, applies the structure across most of the state, with Delaware Electric Cooperative and the Newark and Dover municipal utilities implementing their own versions.

The Delaware SREC market is the second pillar. The state's Renewable Portfolio Standard creates a solar carve-out obligating utilities to purchase Solar Renewable Energy Credits; a residential system earns one SREC per megawatt-hour produced, whether consumed on-site or exported, and sells those credits through PJM-GATS brokers at a floating price (recently around $35/SREC). This is genuine additional income on top of the net-metering offset.

Delaware offers no state income tax credit for solar (its earlier green energy credit expired) and no sales tax exemption, but it does exempt solar systems from property tax on the added value (DE Code Title 25, Chapter 7). The federal Section 25D residential credit expired December 31, 2025; leased and PPA systems may still access Section 48E for projects that began construction before July 6, 2026.

Delaware's 4.5 peak sun hours place it in the mid-Atlantic norm — productive summers offset by shorter, cloudier winter days. The flat Coastal Plain from Wilmington south through Dover to the beaches is remarkably uniform solar-resource-wise, with only marginal variation between the northern tip and the southern Sussex County shore. The main production drag is coastal cloud cover and the occasional nor'easter that can cloud the region for days in winter.

Because Delaware retains full retail net metering with an annual true-up, the optimal strategy is to maximize annual production and bank the summer surplus against winter consumption. A south-facing array tilted near latitude (~38°) captures the most annual kilowatt-hours, and there is no avoided-cost penalty for overproduction. The SREC stream adds a mild incentive to maximize raw output, since every kilowatt-hour produced — consumed or exported — contributes to credit generation at roughly $35/SREC.

Rooftop constraints in older Wilmington and Dover housing stock and tree canopy in established suburbs can push some homeowners toward higher-efficiency panels or ground mounts. The uniformity of the resource across the state means the production equation is governed mostly by the roof, not the region.

Delaware's $3.20/W installed cost sits modestly above the national average, with a typical 8 kW system around $25,600 before incentives. The 30% federal residential credit (Section 25D) ended December 31, 2025, and Delaware offers no state income tax credit, so the structural offsets are limited to the property tax exemption and the SREC income stream. The state does not exempt solar from sales tax.

Payback near 15.8 years on the 8 kW model is held back by the combination of middling retail rates (~$0.16/kWh) and the absence of a state tax credit. The SREC income — roughly $245 a year for an 8 kW system at current $35/SREC pricing — shortens the timeline modestly, as does the property tax exemption. Households with high consumption in Delmarva Power territory see faster payback than the average because each offset kilowatt-hour displaces more spending.

The SREC contract terms (price and term length with the chosen aggregator) are the variable most worth confirming at installation, since that income stream is a meaningful piece of the long-run return.