Solar Panels Q&A

The inverter type is one of the most important decisions in a solar installation. String inverters are a single unit that connects all panels in series — they cost $800-$1,200 less than microinverter systems. However, if one panel is shaded, it reduces output for the entire string. Microinverters attach to each individual panel, allowing each to operate independently, delivering 5-25% higher energy production in partially shaded conditions. Microinverters also offer panel-level monitoring through a mobile app. The downside: microinverters cost 15-20% more upfront and are more complex to replace if they fail. Both typically carry 25-year warranties. Most installers recommend microinverters for roofs with shading issues or complex angles, while string inverters are cost-effective for simple south-facing roofs with full sun.

The ideal roof for solar is less than 10 years old, asphalt shingle or metal, and south-facing with a pitch between 15-40 degrees. If your roof needs replacement within 5-7 years, replace it before installing solar — removing and reinstalling panels costs $3,000-$6,000. An engineer evaluation typically costs $200-$500. Solar-integrated roofing like Tesla Solar Roof replaces actual roofing material, eliminating the timing issue entirely.

Solar installations require building permits ($200-$800), HOA approval in some cases, and a net metering agreement with your utility. The full process takes 1-3 months from contract signing to system activation. After installation, the system must pass municipal inspection, then the utility grants permission to operate before you can turn it on. Some states now offer automated permitting that reduces approval times from weeks to days.

A standard lithium-ion battery adds $10,000-$18,000 installed. The 30% federal tax credit reduces net cost to $7,000-$12,600. Whole-home backup needs 2-3 batteries ($15,000-$35,000 after credits). Battery lifespan is 10-15 years with capacity degrading to 70% after 10 years. Time-of-use arbitrage can save $50-$150 monthly in areas with significant peak rate differentials.

Look for NABCEP certified installers on staff. Get three detailed quotes with exact panel make, inverter type, estimated annual production, and warranty terms. Equipment should have 25-year warranty, workmanship should be 5-10 years. Never pay the full amount upfront — standard is 10-30% deposit with balance due after inspection and permission to operate. Verify the installer handles all permits and interconnection paperwork.

Net energy metering determines how much your utility credits you for excess solar power. Full retail-rate NEM gives maximum savings, but many states have moved to reduced rates. California's NEM 3.0 credits exported power at roughly 75% less than retail, making battery storage more important. Ask your installer to model savings under your specific utility's policy, not national averages.

South-facing roofs at 30-40 degrees produce maximum energy. East/west-facing roofs produce 15-25% less but can align better with morning/afternoon usage. North-facing roofs lose 30-40% and are generally not recommended. Modern high-efficiency panels and microinverters make non-ideal orientations more viable. A professional solar design should include production projections for your specific roof.

Solar panels are remarkably low-maintenance — rainfall is usually sufficient for cleaning. In dry areas, occasional hose cleaning ($150-$300 professional) once or twice a year helps. Monitor system performance monthly through your inverter's app. The most common major expense is inverter replacement ($1,000-$2,000 after 10-15 years). Panels degrade at less than 0.5% per year and typically last 25-30 years.

Standard efficiency panels (18-20%) need 18-22 panels for a typical 7 kW system. High-efficiency panels (22-24%) need only 14-17 panels — important for limited roof space. High-efficiency panels cost 20-40% more per watt. For homes with ample roof space, standard efficiency delivers better value. Tier 1 manufacturers guarantee 80-92% output after 25 years.

Technically possible but not practical — removal and reinstallation costs $5,000-$10,000 with risk of panel damage. Far better to include the system in the home sale. Homes with owned solar sell for 4-6% more. Leased systems complicate resale as buyers must qualify to take over the lease, which is why buying is strongly recommended over leasing for long-term homeowners.