Solar Panels in Delaware (DE)
Last updated: February 24, 2026
Everything you need to know about going solar in Delaware (DE) — costs, savings, incentives, and the best equipment for your climate.
Federal Residential Solar Tax Credit Repealed
The 30% residential solar tax credit (Section 25D) was repealed in early 2026. Homeowners who installed solar before the repeal can still claim the credit. Commercial projects retain the 30% ITC under Section 48/48E. Delaware state incentives remain available.
Sun Hours/Day
4 hrs
Fair Solar Irradiance
8 kW System Cost
$26,400
$3.30/watt installed
Federal Residential ITC
Repealed
Section 25D (early 2026)
Annual Savings
$1,518
11,680 kWh/year
Payback Period
17.4 yrs
then free electricity for 15-20+ yrs
Solar Irradiance in Delaware (2026)
Delaware receives an average of 4 peak sun hours per day annually, equivalent to roughly 1460 kWh/m² per year of global horizontal irradiance (GHI). Summer peaks reach about 5.2 h/day, while winter lows drop to around 2.4 h/day.
This places Delaware in the fair solar irradiance band compared with other US states. At 4 kWh/m²/day, each 1 kW of rooftop solar in Delaware generates approximately 1,139 kWh/year (assuming 78% system performance after inverter, soiling, and temperature losses), which makes an 8 kW system produce around 11,680 kWh per year.
Data source: NREL National Solar Radiation Database (NSRDB), 1998-2020 typical meteorological year averages. Delaware (DE) values reflect the statewide average; coastal, mountain, and desert microclimates can vary by ±15% from this figure.
Delaware Solar Incentives (2026)
Federal residential tax credit was repealed in early 2026. Delaware continues to offer the following state and utility-level programs:
| Incentive | Value | Eligibility | Deadline | Source |
|---|---|---|---|---|
| Federal Section 25D ITC | 0% (Repealed Q1 2026) | N/A | Was 12/31/2025 | IRS |
| Green Energy Program grant | — | — | Verify with state agency | DSIRE |
| Net metering 1:1 | — | — | Verify with state agency | DSIRE |
| SREC market | — | — | Verify with state agency | DSIRE |
⚠ Always verify state incentive deadlines, caps, and eligibility before signing a solar contract — programs change annually and many have annual funding caps that exhaust mid-year.
Major utility companies in Delaware
Check your utility's net metering policy, interconnection requirements, and rate structure before installing — rules vary significantly within Delaware:
- • Delmarva Power (Exelon)
- • Delaware Electric Cooperative
Each utility has different rate structures, net metering caps, and time-of-use schedules. Visit your utility's website for current solar interconnection requirements and queue times.
Net metering in Delaware
Status: Net metering 1:1
Export rate: Full retail rate credit
System size cap: 25 kW residential
⚠ NEM rules can be amended by state public utility commissions and individual utilities — verify with your utility before committing. Caps and rates shown reflect the most common residential tariff as of 2026.
Solar Incentives in Delaware
Federal Residential ITC (Section 25D) -- Repealed
The 30% federal residential solar tax credit (Section 25D) was repealed in early 2026. Homeowners who installed solar before the repeal may still claim the credit for that tax year. Commercial solar projects continue to receive the 30% ITC under Section 48/48E.
State Incentives Available
Delaware offers state-level solar incentives that remain available despite the federal ITC repeal. Check with your local utility and the DSIRE database for current programs.
Top 3 Recommended Solar Panels for Delaware
Delaware's 4 peak sun hours/day provides solid solar potential. These panels deliver the best performance:
| Panel | Wattage | Efficiency | Temp Coeff | Warranty |
|---|---|---|---|---|
| LONGi Hi-MO 7 620W | 620W | 23% | -0.28%/°C | 12/30 yr |
| LONGi Hi-MO 7 590W | 590W | 22.8% | -0.28%/°C | 12/30 yr |
| Trina Solar Vertex N+ 600W | 600W | 22.8% | -0.28%/°C | 15/30 yr |
Top 3 Recommended Batteries for Delaware
Pairing solar with battery storage provides backup power during outages and can optimize savings with time-of-use rates:
| Battery | Capacity | Power | Chemistry | Warranty |
|---|---|---|---|---|
| HomeGrid Stack'd Series 38.4kWh | 38.4 kWh | 34.4 kW | LFP (Lithium Iron Phosphate) | 10 yr |
| HomeGrid Stack'd Series 28.8kWh | 28.8 kWh | 25.8 kW | LFP (Lithium Iron Phosphate) | 10 yr |
| BYD Battery-Box Premium HVM 22.1 | 22.08 kWh | 22.08 kW | LFP (Lithium Iron Phosphate) | 10 yr |
Frequently Asked Questions
How much do solar panels cost in Delaware in 2026?
The average cost of an 8 kW solar system in Delaware is approximately $26,400 ($3.30/watt installed). Note: The federal residential solar tax credit (Section 25D) was repealed in early 2026, so the full system cost applies unless state incentives are available. State-level incentives may reduce your out-of-pocket cost. Get 3-5 quotes from local installers for accurate pricing.
Is the federal solar tax credit available in Delaware?
The federal residential solar tax credit (Section 25D) was repealed in early 2026. Homeowners who installed solar before the repeal can still claim the credit for that tax year. Commercial solar projects continue to receive the 30% ITC under Section 48/48E. Delaware still offers state-level incentives that can reduce your solar costs. Consult a tax professional for the latest guidance.
Is solar a good investment in Delaware?
With 4 peak sun hours/day, Delaware has good solar potential. An 8 kW system costs approximately $26,400 and can pay for itself in about 17.4 years through electricity savings. After payback, you enjoy 15-20+ years of essentially free electricity.
How much can I save with solar in Delaware?
An 8 kW solar system in Delaware produces approximately 11,680 kWh/year, saving about $1,518 annually. The estimated payback period is 17.4 years. Over 25 years, total savings can reach $37,950.
Does Delaware have net metering?
Net metering policies vary by utility in Delaware. Most states offer some form of net metering or net billing that credits solar homeowners for excess electricity sent back to the grid. Contact your local utility or check the DSIRE database for current Delaware net metering policies.
What is the best solar panel for Delaware?
For Delaware with 4 sun hours/day, high-efficiency panels are the best choice to maximize energy production. Look for panels with efficiency ratings above 21%.
What is the payback period for solar in Delaware?
The estimated payback period for an 8 kW solar system in Delaware is 17.4 years. This is calculated as: system cost ($26,400) divided by annual savings ($1,518/year). After payback, solar generates essentially free electricity for 15-20+ more years. State incentives may shorten this further.
Do I need a battery for solar in Delaware?
A battery is not required for grid-tied solar in Delaware, but it provides backup power during outages and can increase savings with time-of-use rate optimization. Delaware's incentive programs may include battery storage rebates.
Does Delaware have solar incentives?
Yes, Delaware offers state-level solar incentives. These may include state tax credits, rebates, property tax exemptions, sales tax exemptions, or SRECs. The federal residential ITC (Section 25D) was repealed in early 2026. Check the DSIRE database for current programs.
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