Understanding Solar Quotes

System size is measured in kilowatts (kW) and determines how much electricity your panels will generate. A typical residential system is 5–10 kW.

Make sure the proposed size matches your actual energy usage. An oversized system wastes money; an undersized one will not cover your bill.

Ask your installer to show the production estimate in kilowatt-hours (kWh) per year and compare it to your annual electricity consumption from your utility bills.

Not all solar panels are equal. Look for the panel brand, model, wattage per panel, and efficiency rating. Premium panels (like SunPower or REC) cost more but produce more power per square foot.

Inverters convert DC power from panels to AC for your home. String inverters are cheapest, microinverters (Enphase) offer panel-level optimization, and power optimizers (SolarEdge) are a middle ground.

Ask about the degradation rate — how much output the panels lose per year. Top panels degrade at 0.25–0.3% annually, while budget panels may degrade at 0.5–0.7%.

A solar proposal should include three types of warranty: product warranty (panels and inverter hardware), production warranty (guaranteed output over time), and workmanship warranty (installation quality).

Top-tier panels offer 25-year product and production warranties. Microinverters typically have 25-year warranties; string inverters are usually 12–15 years.

The workmanship warranty covers the installation itself — look for at least 10 years. Some premium installers offer 25-year roof penetration warranties.

Compare proposals on a cost-per-watt basis (total price divided by system size in watts). In 2026, expect $2.50–$3.50/watt before incentives for a quality installation.

The proposal should clearly show gross cost, applicable tax credits and rebates, and your net out-of-pocket cost.

Be wary of quotes significantly below market rate — they may use low-quality equipment or have hidden fees. Equally, quotes far above average do not always mean better quality.

Cash purchase gives you the best long-term savings and full ownership of the tax credit. Solar loans let you finance with $0 down while still owning the system and claiming the ITC.

Leases and Power Purchase Agreements (PPAs) mean a third party owns your panels. You pay a monthly fee or per-kWh rate, typically lower than your utility. However, you do not get the tax credit.

If financing, compare the total cost over the loan term — not just the monthly payment. A 25-year loan with low payments can cost significantly more than a 10-year loan with higher payments.

High-pressure sales tactics or "today only" pricing. Legitimate solar savings do not expire overnight.

Unrealistic savings projections. If the estimate assumes your electricity rates will double, the numbers are inflated. Ask what rate escalation they used — 2–3% annually is reasonable.

No site assessment before quoting. A reputable installer will assess your roof condition, orientation, shading, and electrical panel before providing a final quote.

Vague or missing warranty terms. If the proposal does not clearly spell out product, production, and workmanship warranties, ask before signing.

Dealers who refuse to provide a written, itemized breakdown of equipment, labor, permitting, and interconnection costs.