What to Know Before Installing Solar Panels

How Many Solar Panels Do You Need?

Your Solar System Estimate

Assumes 400W panels, 80% system efficiency. The federal 30% tax credit expired Dec 31, 2025 and is not applied here — check dsireusa.org for any state/utility incentives in your area. Annual savings based on 100% offset at your electricity rate.

Going solar is one of the most impactful financial and environmental decisions a homeowner can make. But the solar market is complex, full of sales pressure, and easy to get wrong. Here's everything you need to know before signing anything.

How Much Do Solar Panels Cost?

The average U.S. residential solar installation costs $15,000–$25,000 installed, depending on system size, location, and installer. A typical 6kW system runs about $18,000.

Important 2026 update: the 30% federal Residential Clean Energy Credit expired for systems placed in service after December 31, 2025 — a $18,000 system now costs the full $18,000 out of pocket (before any state or utility rebates), not the $12,600 it would have cost in 2025 with the credit. Check dsireusa.org for state and utility incentives that may still apply in your area.

What Happened to the 30% Federal Tax Credit

The Inflation Reduction Act originally extended the solar Residential Clean Energy Credit (Section 25D) at 30% through 2032. The One Big Beautiful Bill Act (OBBBA), signed July 4, 2025, accelerated its termination to December 31, 2025 — so it no longer applies to systems placed in service in 2026 or later. If your system was installed and operational by the end of 2025, you can still claim the credit on that year's return; new 2026 installations get no federal credit at all.

Some state, local, and utility incentives are unaffected by this change and may still meaningfully reduce your cost — check dsireusa.org for what's available where you live.

How Much Can You Save?

The average 6kW system in the U.S. generates about 7,000–9,000 kWh per year, offsetting 60–100% of a typical home's electricity use. At the national average electricity rate of ~18¢/kWh, that's $1,300–1,600/year in savings — more in high-rate states like California ($0.25+/kWh) or Hawaii.

Use our Solar Panel Savings Calculator to estimate your specific savings based on location and system size.

Is Your Roof Ready?

Before getting quotes, check your roof's age, condition, and orientation:

  • Age: If your roof is over 15 years old, consider replacing it before going solar. Removing and reinstalling panels for a roof replacement can cost $3,000–5,000 extra.
  • Orientation: South-facing roofs at a 30° pitch are optimal. East/west-facing panels produce 10–20% less; north-facing is not recommended.
  • Shading: Even partial shading from trees or chimneys significantly reduces output. Microinverters or power optimizers mitigate this.
  • Structural integrity: Your roof must be able to support ~3–4 lbs per sq ft of additional load.

Choosing an Installer

This is where most homeowners make mistakes. The solar industry has a significant number of aggressive or unscrupulous installers. Here's how to choose well:

  • Get at least 3 quotes — prices can vary by 20–30% for the same system
  • Check for NABCEP certification (the gold standard for solar installers)
  • Read Google and BBB reviews carefully
  • Avoid high-pressure tactics or "today only" deals
  • Ask whether they subcontract the installation (many large companies do)

Buying vs Leasing vs PPA

Buying outright (cash or loan) gives you full ownership and maximum long-term savings once the system is paid off. Solar leases and PPAs (power purchase agreements) let you go solar with no upfront cost. Since the federal buyer's tax credit expired for 2026 installs, buying no longer has the automatic "capture the credit" advantage it used to — some lease/PPA providers, as system owners, may still access a separate commercial credit and structure payments accordingly. Compare actual quotes rather than assuming buying wins by default.

If you can't afford to buy, a solar loan is usually better than a lease. Look for low-interest green energy loans through your bank, credit union, or state clean energy programs.

What Payback Period Should You Expect?

Without the expired federal tax credit, the average solar payback period in the U.S. is now roughly 9–14 years. In high-sun, high-rate states (CA, AZ, HI, MA), it can still be 6–9 years thanks to higher electricity rates and any remaining state incentives. In low-sun states with lower rates (PNW, Midwest), 13–16 years is more typical now.

Given that quality solar panels come with 25-year performance warranties, even a 14-year payback leaves you with over a decade of pure profit. Use our Solar ROI Calculator to model your specific scenario.

Bottom line: Solar can still be a good investment for many homeowners, but the math changed in 2026 now that the 30% federal tax credit has expired. Get multiple quotes, check your roof first, and look into any state or utility incentives before assuming the old numbers still apply.

Understanding Your Solar Quote

When you receive a solar quote, you'll typically see the system size in kilowatts (kW), the estimated annual production in kilowatt-hours (kWh), and the total installed cost. As of 2026 there's no federal tax credit to subtract, so scrutinize the gross price carefully:

  • Price per watt: Divide the gross system cost by the system size in watts. A fair price is $2.50–$3.50/watt before incentives in most markets. Significantly higher suggests markup; significantly lower might indicate low-quality components.
  • Production estimate: The quote should include a production estimate based on your roof's orientation, tilt, and shading. Ask what software they used (PVWatts, Aurora, or Helioscope are industry standards) and what assumptions they made.
  • Panel brand and warranty: Tier 1 panels (Jinko, LONGi, Canadian Solar, REC, Panasonic) come with 25-year product and performance warranties. Ask specifically about the performance warranty — it should guarantee at least 80% of rated output after 25 years.
  • Inverter type: String inverters are cheaper but suffer from whole-system performance drops if one panel is shaded. Microinverters or power optimizers cost more but optimize each panel independently — worth it for roofs with any shading.

Grid-Tied vs Off-Grid Solar

The vast majority of residential solar installations are grid-tied — your panels produce electricity during the day, excess goes to the grid, and you draw from the grid at night. You remain connected to your utility and benefit from net metering credits. This is the right choice for most homeowners: lower cost, no battery required, and no risk of running out of power.

Off-grid solar makes sense for remote properties without utility access, or for homeowners who want energy independence at any cost. It requires a significantly larger battery bank and a backup generator, adding substantially to system cost. For most suburban and urban homeowners, adding battery storage to a grid-tied system gives the resilience benefits of off-grid without the full cost.

Solar and Home Resale Value

Multiple studies, including Zillow research and Lawrence Berkeley National Laboratory data, have found that solar panels increase home resale value. The premium averages roughly $4 per watt of installed capacity — meaning a 6kW system could add about $24,000 to your home's value. This premium varies by market: it's stronger in states with high electricity rates and established solar markets (California, Massachusetts, New Jersey) and weaker in low-rate states with less solar adoption.

Importantly, this value premium generally applies only to owned systems, not leased systems or PPAs. Buyers can be hesitant to take on a solar lease, and it can complicate the sale process.

How Much CO2 Does Going Solar Actually Save?

Beyond the financial case, solar is one of the highest-impact carbon reduction actions a homeowner can take. A typical 6kW system offsets approximately 4.5–6 metric tons of CO2 per year — equivalent to planting about 230 trees annually, or taking one gas car off the road entirely.

The exact carbon offset depends on your grid region: homes in coal-heavy states like Indiana or Ohio offset 6–7 tons/year, while homes on the cleaner West Coast grid offset 2.5–4 tons/year. Over a 25-year system lifespan, even in a cleaner-grid state, a 6kW system accumulates 60–145 metric tons of net CO2 offset. Use our Solar CO2 Offset Calculator to see your specific numbers — and how many equivalent trees that represents.

Common Mistakes to Avoid

  • Not getting multiple quotes: Solar prices vary 20–30% between installers for the same system. Always get at least three quotes.
  • Choosing a lease or PPA without understanding the terms: Read the escalator clause — some agreements increase your payments by 2–3% per year.
  • Oversizing the system: If your utility doesn't offer full retail net metering, excess production above your usage may be credited at a lower rate. Size your system to your actual usage — our net metering calculator shows exactly what that costs you.
  • Not asking about permits and interconnection: A reputable installer handles all permits and utility interconnection. Ask upfront how long this process takes — it can add weeks to the timeline.
  • Ignoring the roof condition: If your roof needs replacement within 10 years, do it before installing solar. Removing and reinstalling panels for a roof job costs $3,000–5,000.

Related Calculators

Solar Panel Savings → Solar ROI Calculator → Solar CO2 Offset → Green Upgrade ROI →

Frequently Asked Questions

How many solar panels do I need for my home?

Most U.S. homes need 15–22 panels to cover 100% of electricity use. A home using 900 kWh/month typically needs a 6–7 kW system (15–18 panels at 400W). Use the calculator above with your actual monthly usage for a personalized estimate.

How much do solar panels cost in 2026?

Installed cost runs $2.50–$3.50 per watt, or $15,000–$25,000 for a typical home system. The federal 30% tax credit expired for systems installed after December 31, 2025, so most 2026 buyers pay the full price minus any state or utility rebates.

Is the 30% solar tax credit still available in 2026?

No. The federal solar Investment Tax Credit (Residential Clean Energy Credit, Section 25D) at 30% was eliminated by the One Big Beautiful Bill Act for systems placed in service after December 31, 2025. It does not apply to 2026 installations. Check dsireusa.org for any state or utility incentives still available where you live.

How long does solar payback take?

Without the expired federal credit, the U.S. average is now roughly 9–14 years. In high-rate states (California, Hawaii, Massachusetts), payback can still be 6–9 years. In low-rate states, it may reach 13–16 years. The calculator above shows your specific payback based on your electricity rate.

What direction should my solar panels face?

South-facing at 30° is optimal. East or west-facing produces 10–20% less but is still worthwhile. North-facing is not recommended. Shading from trees or chimneys can reduce output by 20–40% — microinverters mitigate shading losses.

Should I buy or lease solar panels?

This is a closer call than it used to be. With the federal buyer's tax credit gone for 2026 installs, buying no longer has that automatic advantage, while some lease and PPA providers (as system owners) may still access a separate commercial credit (Section 48E, available through 2027) and pass part of the savings to you through the payment structure. Run the numbers on your specific quotes — including current financing rates — rather than assuming buying wins by default.

How much CO2 do solar panels offset?

A typical 6kW residential solar system offsets approximately 4.5–6 metric tons of CO2 per year, depending on your grid region. Over a 25-year lifespan, that's roughly 110–145 metric tons — equivalent to planting about 230 trees every year. Use our Solar CO2 Offset Calculator for your specific numbers.

Does going solar increase home value?

Yes. Studies including Lawrence Berkeley National Laboratory data show that owned solar systems add roughly $4 per watt of installed capacity to home resale value — about $24,000 for a typical 6kW system. This premium is strongest in high-rate states like California, Massachusetts, and New Jersey. It generally applies only to owned systems, not leased ones.