☀️ Solar Panel Calculator

Estimate your solar panel system size, energy production, cost savings, and return on investment. Go green and save money!

Size Your Solar System

Average Monthly Electric Bill

Electricity Rate

$/kWh

Peak Sun Hours (Daily Average)

Energy Offset Goal

Panel Wattage

Recommended System

8.5 kW

System Size

Monthly Usage

1,071 kWh

Panels Needed

22 panels

Roof Space Needed

~385 sq ft

Annual Production

12,410 kWh

4 peak hrs/day ? 34 kWh/day

Calculate Your Savings

System Size (kW)

Peak Sun Hours

hrs/day

Your Electricity Rate

$/kWh

Annual Rate Increase (Estimate)

Your Savings Potential

$1,738

First Year Savings

Monthly Savings

$145

Annual Production

12,410 kWh

25-Year Savings

$63,500

CO2 Avoided/Year

8.7 tons

?? That's equivalent to planting 140 trees per year!

ROI & Payback Period

System Size (kW)

Installation Cost (per Watt)

Federal Tax Credit (ITC)

State/Local Incentives

Estimated Annual Savings

Your Investment

9.4 yrs

Payback Period

Gross System Cost

$23,375

Federal Tax Credit

-$7,013

Net System Cost

$16,363

25-Year ROI

288%

?? Net profit over 25 years: $47,137

Understanding Solar Panel Systems

Solar photovoltaic (PV) systems convert sunlight into electricity using semiconductor cells. A residential solar installation can significantly reduce or eliminate your electricity bills while reducing your carbon footprint.

How Solar Panels Work

Sunlight hits the panels: Photovoltaic cells absorb photons from sunlight
DC electricity generated: The solar cells produce direct current (DC) electricity
Inverter converts power: An inverter converts DC to alternating current (AC)
Power your home: AC electricity flows to your home's electrical panel
Net metering: Excess energy goes to the grid, spinning your meter backward

Average Solar Costs by System Size

System Size	Avg. Panels	Gross Cost	After 30% ITC
4 kW	10-12	$11,000 - $14,000	$7,700 - $9,800
6 kW	15-18	$16,500 - $21,000	$11,550 - $14,700
8 kW	20-24	$22,000 - $28,000	$15,400 - $19,600
10 kW	25-30	$27,500 - $35,000	$19,250 - $24,500
12 kW	30-36	$33,000 - $42,000	$23,100 - $29,400

Peak Sun Hours Matter!

Peak sun hours vary greatly by location. Phoenix averages 6.5 hours while Seattle averages 3.5 hours. Your system size needs to account for your local solar resource. Use the NREL PVWatts Calculator for precise local data.

Benefits of Going Solar

Lower Electric Bills

Reduce or eliminate your monthly electricity costs. Net metering lets you sell excess power back to the grid.

Increase Home Value

Studies show solar panels can increase home values by 3-4%. Buyers pay premium for solar-equipped homes.

Environmental Impact

A typical system offsets 3-4 tons of carbon annually×equivalent to planting 100+ trees each year.

Energy Independence

Protect yourself from rising utility rates. Lock in your energy costs for 25+ years.

Tax Incentives

The 30% federal tax credit (ITC) through 2032, plus many state and local incentives.

Low Maintenance

Solar panels have no moving parts and require minimal maintenance. Most systems last 25-30+ years.

Solar Panel ROI & Payback Period Reference (2026)

Solar economics vary significantly by electricity rate, sunlight hours, and state incentives. The federal ITC (Investment Tax Credit) provides a 30% tax credit through 2032. These figures use average US electricity cost of 16.2×/kWh:

System Size	Gross Cost	After 30% ITC	Annual Savings	Payback Period
4 kW (small home)	$11,000×$14,000	$7,700×$9,800	$700×$900/yr	9×12 years
6 kW (medium home)	$15,000×$19,000	$10,500×$13,300	$1,000×$1,350/yr	8×11 years
8 kW (large home)	$19,000×$24,000	$13,300×$16,800	$1,300×$1,800/yr	8×11 years
10 kW (high usage)	$23,000×$29,000	$16,100×$20,300	$1,600×$2,200/yr	8×11 years

Solar Savings by State (Key Markets)

State	Electricity Rate	Annual Sun Hours	6kW System Saves
California	24.1×	2,000+	$2,900/yr
Texas	13.6×	1,850	$1,520/yr
Florida	15.1×	1,800	$1,630/yr
Massachusetts	24.6×	1,400	$2,060/yr

? Frequently Asked Questions

How many solar panels do I need for my home? +

The number of panels depends on your energy usage, roof space, panel efficiency, and local sun hours. A typical US home uses about 900 kWh/month and needs a 6-8 kW system (15-20 panels). Use our calculator above with your actual electric bill for a personalized estimate.

How long do solar panels last? +

Modern solar panels are designed to last 25-30+ years. Most manufacturers guarantee at least 80% production at 25 years. Panels don't suddenly stop working×they gradually produce slightly less power over time (about 0.5% degradation per year). Many systems from the 1980s are still producing power today.

What's the federal solar tax credit? +

The Investment Tax Credit (ITC) allows you to deduct 30% of your solar installation cost from your federal taxes. For a $20,000 system, that's a $6,000 tax credit. This rate applies through 2032, then drops to 26% in 2033 and 22% in 2034. It's a credit, not a deduction, meaning it directly reduces your tax bill dollar-for-dollar.

Do solar panels work on cloudy days? +

Yes! Solar panels still produce electricity on cloudy days, though at reduced capacity (typically 10-25% of their rated output). Panels use diffuse light, not just direct sunlight. Germany, which is cloudier than most US states, is one of the world's leading solar markets. That said, cloudier climates will need larger systems to offset the same usage.

Should I add a battery backup system? +

Batteries (like Tesla Powerwall) add $10,000-$15,000 but provide backup power during outages and can store excess solar for nighttime use. They make most sense if: you experience frequent power outages, have time-of-use rates with expensive evening electricity, or want energy independence. Without batteries, standard grid-tied systems turn off during outages for safety.