Comparing solar installation quotes in Washington, DC, Maryland, and Northern Virginia
Solar quotes can look similar at first glance but vary significantly in equipment, warranties, financing, and what's actually included. This checklist helps you compare apples to apples.
System specifications to compare
System size (kW): Total panel wattage divided by 1,000. A 10 kW system with 400W panels uses 25 panels.
Estimated annual production (kWh): How much electricity the system is expected to generate in year one. Compare this to your actual usage from utility bills.
Production estimate methodology: Is it based on site-specific shading analysis or a generic assumption? Site-specific is more accurate.
Equipment list: Specific panel manufacturer, model, and wattage. Specific inverter manufacturer and model. Battery if applicable.
Design layout: Where will panels be placed? Which roof facets will be used? How will conduit be routed?
Financial terms to compare
Total gross cost: Before incentives. This is the number to compare across quotes.
Cost per watt: Gross cost divided by system size in watts. In the DMV, $2.50–$4.00 per watt is typical depending on equipment and complexity.
Incentive-adjusted cost: Subtract only incentives for which you have verified eligibility and a current program source. The gross cost should remain visible so competing quotes are compared on the same basis.
Financing terms: If using a loan, compare interest rate, loan term, monthly payment, and total interest paid. Some solar loans have dealer fees that increase the effective interest rate.
Escalator clauses (leases/PPAs): If the payment increases over time, what is the annual escalator percentage?
What's included
Permits and inspections: Who handles permits? Which jurisdictions?
Interconnection application: Who submits the utility interconnection request?
Monitoring: Is production monitoring included? For how long?
Warranty and service
Equipment warranties: Panel performance warranty (typically 25 years), panel product warranty (10–25 years), inverter warranty (10–25 years).
Workmanship warranty: Installer's warranty on labor and roof penetrations. 5–10 years is typical; 10–25 years from premium installers.
Production guarantee: Some installers guarantee a minimum production level and compensate you if the system underperforms.
Response time for service calls: What happens if something breaks? How quickly will they respond?
Red flags to watch for
- Pressure to sign immediately
- Quotes significantly lower than others (may indicate corners cut or equipment differences)
- Vague equipment descriptions ("premium panels" without naming the brand)
- No mention of permits or interconnection
- Lease/PPA presented as clearly better without explaining ownership trade-offs
- Installer cannot provide proof of insurance or license
DMV-specific verification
Verify the installer holds a valid Virginia, Maryland, or DC contractor license as applicable. Check for:
- MHIC license (Maryland)
- Class A, B, or C contractor license (Virginia)
- Basic Business License (DC)
Confirm the installer has experience with your jurisdiction's permitting and interconnection processes.
How Renovessa helps
When you use Renovessa to request solar quotes, we help organize proposals from multiple installers in a standardized format. This makes equipment, pricing, and warranty comparisons straightforward.