How Much Does Solar Installation Cost in Delaware?

The average Delaware solar installation cost for a residential system that meets the energy needs of an average household (around 7 kW) ranges from $18,900 to $22,400 before incentives, or roughly $2.70 to $3.20 per watt. After applying the 30% federal Investment Tax Credit (ITC), most homeowners can expect to pay around $13,200 to $15,700 out of pocket. Delaware also offers additional savings through property-tax exemptions and local utility rebates, which further lower the total cost of going solar.

These figures represent the turnkey cost, which includes hardware (solar panels, inverters, mounting, batteries) and soft costs (labor, permitting, inspections, and overhead). The table below summarizes the breakdown of a typical Delaware solar installation in 2025:

The Delaware solar market benefits from relatively low permitting fees and supportive interconnection policies, which help reduce soft costs compared with neighboring states. Most homeowners choose Tier 1 monocrystalline panels, which have higher efficiency (19 – 22%) and longer warranties, up to 25 years on performance and equipment.

Homeowners in Delaware can also combine the federal ITC with state-level benefits such as:

• Delaware Green Energy Program rebates, available through utilities like Delmarva Power, offering rebates of $500 to $1,000 per kW (capped at around $6,000 to $8,000)
• Property-tax exemptions on the added home value from solar energy systems
• Net-metering credits, allowing customers to earn bill credits for excess power sent to the grid at retail rates

With these combined incentives, Delaware homeowners often achieve system payback in 7 to 9 years, with an average lifetime savings exceeding $30,000 over 25 years.

Finding the Right Solar Installer in Delaware

Choosing the right solar installer is one of the most important decisions for ensuring a high-quality and long-lasting system. Delaware residents should evaluate solar installation companies based on technical expertise, reputation, and transparency.

The state has several certified solar panel installers who handle residential and commercial systems under the Delaware Renewable Energy Task Force’s guidelines. Here are key qualities to look for when selecting a contractor:

• Experience and Certification: Verify that the solar installation company holds relevant licenses and North American Board of Certified Energy Practitioners (NABCEP) certification. Installers with at least five years of experience typically offer smoother project management and fewer delays
• Local Knowledge: A solar installer familiar with Delaware’s climate, roof types, and permitting process can better navigate local utility requirements and zoning regulations
• Comprehensive Warranties: Choose installers offering at least 10 years workmanship warranty in addition to panel and inverter warranties
• Transparent Pricing: Reputable solar installation companies provide detailed cost breakdowns, specify equipment brands, and include estimated payback periods in their proposals
• Customer Reviews and References: Past customer feedback can reveal how well the company handles service requests, post-installation maintenance, and warranty claims

It is advisable to request three or more solar installation proposals before signing a contract. Comparing bids helps identify realistic pricing, appropriate equipment, and fair terms. A reliable solar installer should also help homeowners navigate available incentives and assist with solar permits and interconnection paperwork.

What Permits Do You Need to Install Solar Panels in Delaware?

Yes, homeowners in Delaware are required to obtain solar permits before installation begins. The process typically involves building, electrical, and sometimes zoning permits, depending on the municipality.

• State and Local Permits: Each county, New Castle, Kent, and Sussex, has its own permitting requirements. Generally, a building permit is required to ensure roof structural safety, and an electrical permit verifies compliance with the National Electrical Code (NEC)
• Utility Interconnection Approval: Delaware utilities such as Delmarva Power, Delaware Electric Cooperative (DEC), and Delaware Municipal Electric Corporation (DEMEC) require interconnection applications before system activation. This ensures that the system meets grid safety and performance standards
• HOA and Community Rules: While Delaware does not have a statewide solar access law, many communities governed by Homeowners’ Associations (HOAs) have internal guidelines for solar panel placement. HOAs cannot outright prohibit solar energy systems under Delaware’s Renewable Energy Portfolio Standards (REPS), but they can regulate aesthetics or installation methods, provided these rules do not unreasonably restrict efficiency
• Inspection: After the solar installation is complete, local inspectors must approve the electrical and structural work before the utility grants permission to operate (PTO)

A licensed solar installer typically handles the full permitting process, ensuring compliance with local and state regulations while minimizing delays.

How to Evaluate a Delaware Solar Proposal

A solar installation proposal is a preliminary document prepared by a solar panel installer outlining the design, costs, equipment, production estimates, and incentives for a solar system. It differs from a solar installation contract, which is a legally binding agreement finalized once a homeowner decides to proceed with the project.

Before signing, homeowners should request and compare multiple proposals from reputable solar installation companies. Evaluating several offers helps ensure competitive pricing, proper system sizing, and accurate savings projections.

A standard Delaware solar proposal should include:

• System Size and Layout: Proposed capacity (in kW), number of panels, roof layout, and orientation
• Equipment Details: Panel brand and model, inverter type (string, microinverter, or hybrid), racking, and optional battery systems
• Cost Breakdown: Itemized list of materials, labor, and permitting fees
• Production Estimates: Annual and lifetime energy generation projections, usually modeled using software like PVWatts or HelioScope
• Financial Analysis: Cash price, financing options, incentives, and projected payback period
• Warranty Coverage: Details on product, performance, and workmanship warranties
• Timeline: Estimated start and completion dates for the solar installation process

Well-prepared proposals are typically accompanied by satellite imagery, shade analysis, and a performance guarantee from the solar installation company.

What to Look for in Delaware Solar Installation Contracts

A solar installation contract is the legally binding document that finalizes the purchase or lease of a solar energy system. In Delaware, written contracts are required for all residential installations to protect consumers and clarify expectations between homeowners and solar installation companies.

Scope of Work and Equipment

This section of the solar contract outlines the full scope of services: design, permitting, installation, inspection, and interconnection. It should list all equipment (panels, inverters, racking systems, batteries) and specify model numbers, warranties, and efficiency ratings.

Homeowners should verify that the listed equipment matches what was presented in the solar installation proposal. Substitutions or “equivalent models” should be pre-approved in writing.

Payment Terms and Schedule

Delaware regulations require clear disclosure of all charges, including deposits, milestone payments, and any financing arrangements. Most solar installation contracts follow this payment structure:

• 10 to 20% deposit upon signing the contract
• 40 to 50% upon equipment delivery or mid-installation
• Final payment after system inspection and PTO approval

Contracts should also include clauses addressing delays, change orders, and refund terms.

Warranties and Guarantees

Warranties protect the homeowner’s investment and are critical to understanding system reliability. Typical Delaware solar installation contracts include:

• Performance Warranty: Guarantees 80 to 85% production capacity for at least 25 years
• Equipment Warranty: Covers defects for 20 to 25 years for panels and 10 to 12 years for inverters
• Workmanship Warranty: Usually 10 years, ensuring the quality of labor and installation

Maintenance and Monitoring

A good solar contract defines who is responsible for routine maintenance, software updates, and monitoring. Many solar installation companies offer online monitoring portals that allow homeowners to track system output in real-time.

Transferability and Ownership

If the homeowner sells the property, the solar installation contract should clarify transfer procedures. For owned systems, ownership typically passes with the home; for financed or leased systems, the buyer must qualify under the same terms or assume the agreement.

How to Read Delaware Solar Leases

A solar lease, also known as a power purchase agreement (PPA), allows homeowners to use solar energy without purchasing the equipment outright. Instead, they agree to pay either a fixed monthly rate or a per-kilowatt-hour charge for the power the system generates.

When reviewing a Delaware solar lease, pay close attention to the following contract terms:

• Contract Length: Most solar leases and PPAs run 15 to 25 years, though shorter terms are emerging as solar prices decline
• Option to Buy: Many agreements allow homeowners to purchase the system after a certain period, often at fair market value after 5 to 10 years
• Escalation Clause: This clause outlines the annual rate increase (typically 1 to 3%) applied to payments over time. Verify that it aligns with or stays below expected utility rate inflation
• Maintenance and Insurance: The leasing company usually handles system upkeep and insurance, ensuring the homeowner bears minimal responsibility
• System Removal or Renewal: The solar lease should define what happens at the end of the term, whether the system is removed, renewed, or transferred to a new owner
• Performance Guarantee: Some solar installation companies include energy-output guarantees, compensating homeowners if the system produces less than projected