Why quotes for a 1,500 sq ft house can look very different
Size alone doesn’t determine cost. Two houses with the same square footage can have very different energy needs, roof layouts, and shading. A one-bedroom home with low usage may need a much smaller system than a family that runs electric HVAC or a shop. Local electricity rates and available incentives also affect how big a system makes sense. Expect estimates to vary because installers size systems differently, use different equipment, and make different assumptions about production.
What to compare on solar quotes
When you get quotes, compare the same basic items so you’re not comparing apples to oranges. Key things to line up: system size in kilowatts, estimated annual production, panel brand and efficiency, inverter type, equipment warranties (what they cover), installer warranty and company reputation, and how the price is presented (cash price, lease, or loan). Ask for the estimate on the same expected production target so you can see price per expected kWh. If a company lists brands like Sunrun, SunPower, or Tesla Energy Solar, note that equipment choice affects long-term performance and service.
Roof, site, and permit factors that change the price
Roof condition and slope: older or damaged roofs often need repair or replacement before panels go on, which raises cost. Orientation and tilt: south-facing, unshaded roofs produce more energy for the same number of panels. Shading: mature trees or nearby buildings can lower production and push installers to alter layouts or add microinverters/optimizers. Access and complexity: steep roofs, multiple roof angles, solar on ground-mounted racks, or difficult electrical runs increase labor. Local permitting, inspection fees, and interconnection rules also vary by city or utility and add to the final price.
How the installer and equipment affect what you pay
Installers price differently for labor, overhead, and service. National firms and local companies both have pros and cons: national brands may offer standardized processes and financing relationships; local crews may provide more personalized service and faster response. Equipment brands matter too — higher-efficiency panels cost more per panel but might need fewer panels for the same production. Inverters and panel-level electronics add to system cost but can improve output on shaded roofs. Ask each installer about performance expectations and the warranties they back, then balance price with track record and responsiveness.