The biggest mistake homeowners make when planning a solar installation is treating the roof as an afterthought. Solar arrays last 25 to 30 years. If your asphalt shingles are already 15 years old, replace the roof before installation, not after. Removing and reinstalling a solar array later costs between $2,500 and $5,000, easily erasing the savings of postponing a re-roof. Have a roofing contractor evaluate condition independently of the solar installer's assessment; the two have different incentives.
Pull 12 months of electricity bills and total your annual kilowatt-hour consumption. Most well-designed residential systems are sized to offset 80 to 100 percent of historical usage, taking into account roof orientation and shading. Going larger sounds appealing but rarely pencils out because most utilities now compensate excess production at wholesale rates, not retail. If you plan to add an electric vehicle, a heat pump, or a heat pump water heater within the next five years, size the system to anticipated future load rather than current use.
Adding battery storage during the original installation is significantly cheaper than retrofitting later. Even a small 5 to 10 kilowatt-hour battery provides resilience during grid outages and enables time-of-use arbitrage in markets where it is permitted. The federal residential clean energy credit continues through 2032 at 30 percent for both solar and storage when installed together, which materially improves the math.
A real proposal includes panel model and wattage, inverter brand, mounting hardware, conduit routing, production estimate based on a shade analysis, total system cost, financing details, and the company's roof penetration warranty. Beware proposals that quote only monthly payments or that promise unrealistic production. Cross-check production estimates against the National Renewable Energy Laboratory's PVWatts calculator using your address.
A typical solar project requires a structural review, an electrical permit, and an interconnection agreement with the utility. The structural review confirms the roof can carry the panel load. The electrical permit verifies the main service panel and breaker capacity. The interconnection agreement establishes how power flows back to the grid and what metering equipment is required. Each step has its own timeline, and most projects take 60 to 120 days from contract signing to power-on.
Even the best installations end with a punch list: conduit that needs to be re-routed for cleaner aesthetics, missing warranty paperwork, or inspection items the city wants addressed. Hold a meaningful final payment, typically 10 percent, until the system is producing, the monitoring portal is active, and you have copies of all permits, inspection sign-offs, and manufacturer warranties in hand.
Connect with verified professionals through Buildingconnection.com — backed by the RealtyChain trust network.
Get a Free Quote →