Solar Panel Calculator — Free Savings, Payback Period & 25-Year ROI Tool 2026
Your electricity bill is $150/month. You’ve heard solar could eliminate it. But before you call an installer, you need to know three things: how much will a system actually cost, when does it pay for itself, and what’s the total savings over the life of the panels. Most solar company calculators are lead-generation tools — they give you optimistic numbers and route you to a sales call.
This calculator gives you the honest math. Enter your monthly electricity bill, system size, sun hours, cost, and electricity rate. It shows annual savings, exact payback year, 25-year total ROI, how many panels you need, your federal tax credit dollar amount, net metering estimate, and CO2 offset — for the US, UK, Australia, and Canada. No signup. No sales call.
Solar Panel Calculator
Bill savings, appliances, roof angle, incentives, net metering and battery payback
Bill-Based Solar Estimate
Use your monthly bill, system size, sun hours and rate to estimate savings, incentives and payback.
Appliance Load Calculator
Enter appliance quantity and hours per day. This tab can auto-fill the main system size.
Roof Angle & Direction
Change latitude or roof direction to see the tilt recommendation and adjusted annual output.
Battery Storage Add-On
Estimate battery net cost, usable stored energy, annual value and combined payback.
Export rate varies by utility. This estimate uses a country-level default export rate.
What This Solar Panel Calculator Shows
Annual Savings and Monthly Savings
Your annual solar savings = system’s annual energy production (kWh) × your electricity rate per kWh. A 9.5kW system in a location with 5 peak sun hours generates approximately 9.5 × 5 × 365 = 17,338 kWh/year. At $0.14/kWh: $2,427/year in savings, or $202/month. At $0.28/kWh (California average): $4,855/year, $405/month.
Payback Period — The Exact Year Your System Pays for Itself
Payback Period = Net System Cost (after incentives) ÷ Annual Savings.
A $24,000 system with 30% ITC: net cost = $16,800. Annual savings at $0.14/kWh: $2,427. Payback = 6.9 years — your system pays itself off in Year 7. After that, every kWh your panels generate is pure profit for the remaining 18 years of panel life.
25-Year Savings Projection
The 25-year projection compounds your savings at your entered annual electricity rate increase (default 3%/year — the US historical average). Year 1 savings: $2,427. Year 10 savings: $3,261 (rates increased 34%). Year 25 savings: $5,079. Cumulative 25-year savings: approximately $86,000 on a 9.5kW system at $0.14/kWh, 3% rate increase.
How Many Solar Panels Do I Need
Panel count = System size (kW) × 1,000 ÷ Panel wattage (standard 400W panel). 9.5kW system ÷ 400W per panel = 24 panels. The output shows panel count prominently alongside roof space required (each 400W panel needs approximately 18 sq ft — 24 panels require approximately 432 sq ft of usable roof space).
Federal Tax Credit — Your Exact Dollar Amount
The US 30% Investment Tax Credit (ITC) applies to the full installed cost of your system including equipment, labor, and permitting through 2032. On a $24,000 system: $7,200 tax credit. This reduces your net cost to $16,800 before any state incentives. The calculator shows the exact ITC dollar amount for your entered system cost.
Country-specific incentives:
- US: 30% ITC (Section 25D) through 2032
- UK: 0% VAT on installation (saved from 20% — effectively 16.7% discount on install labor)
- AUS: Small-scale Technology Certificates (STCs) — approximately $2,500–$4,500 rebate on typical systems
- CAN: Canada Greener Homes Grant (up to $5,000) + provincial programs vary
Net Metering Estimate
When your panels produce more electricity than you use, the surplus goes back to the grid. Net metering calculates credits from this surplus export. Estimated annual export value = (Annual production − Annual consumption) × electricity rate. The net metering section shows your estimated export credit and flags states/regions with favorable full-retail net metering versus those with reduced compensation rates.
CO2 Offset and Trees Equivalent
A 9.5kW system producing 17,338 kWh/year offsets approximately 12.2 metric tons of CO2 annually (based on EPA’s average US grid emission factor of 0.386 kg CO2 per kWh). Equivalent to planting approximately 565 trees per year, or taking 2.6 cars off the road.
Solar Panel Calculator — How the Numbers Are Calculated
How Solar Savings Are Calculated
Step 1: System annual output (kWh) Annual kWh = System size (kW) × Daily sun hours × 365 × System efficiency factor (0.80 — accounts for inverter losses, panel degradation, temperature, shading)
9.5kW × 5 hours × 365 × 0.80 = 13,870 kWh/year (conservative estimate)
Step 2: Annual bill offset Annual savings = Annual kWh × Electricity rate per kWh 13,870 × $0.14 = $1,942/year at US average rate 13,870 × $0.28 = $3,884/year at California rate
Step 3: Compound savings over 25 years Year N savings = Year 1 savings × (1 + rate increase)^N At 3% annual rate increase: Year 7 savings = $1,942 × 1.23 = $2,389
Step 4: Payback Net system cost ÷ Year 1 annual savings = Payback in years ($24,000 − $7,200 ITC) ÷ $1,942 = 8.65 years at US average rate ($24,000 − $7,200 ITC) ÷ $3,884 = 4.33 years at California rate
Why This Calculator Uses 0.80 System Efficiency
Most competitor calculators use theoretical peak output — every kW of installed capacity producing 1kWh per peak sun hour. Real-world systems produce 15%–25% less due to:
- Inverter losses: DC-to-AC conversion loses 4%–8%
- Panel degradation: Panels lose 0.5%–0.7% efficiency per year
- Temperature effects: Panels lose efficiency above 25°C — 0.3%–0.5% per degree Celsius above optimal
- Shading and soiling: Even partial shade from chimneys or leaves reduces output
- Wiring losses: DC wiring resistance losses of 1%–3%
Using 0.80 efficiency (80% of peak) produces conservative, realistic estimates. Most competitor tools overstate savings by 15%–25% by ignoring these factors.
Solar Panel Cost Calculator — 2026 Installation Costs
How Much Do Solar Panels Cost in 2026?
The national average solar panel installation cost in the US is approximately $2.75–$3.25 per watt before incentives. For common system sizes:
| System Size | Best For | Cost Range (Before ITC) | Cost After 30% ITC |
|---|---|---|---|
| 4–5 kW | Small home (1–2 bed) | $11,000–$16,250 | $7,700–$11,375 |
| 6–8 kW | Medium home (3 bed) | $16,500–$26,000 | $11,550–$18,200 |
| 9–12 kW | Large home (4–5 bed) | $24,750–$39,000 | $17,325–$27,300 |
| 13–15 kW | Very large / EV charging | $35,750–$48,750 | $25,025–$34,125 |
US average: $24,000 for an 8kW system ($3.00/watt) before incentives. After 30% ITC: $16,800.
Solar Panel Installation Cost Calculator — What Drives the Price
Equipment: Panels (35%–40%), inverter (10%–15%), racking and hardware (5%–10%), wiring and electrical (5%–8%).
Labor: Installation labor (15%–20%), electrical work (5%–10%).
Soft costs: Permits and inspections (5%–8%), design and engineering (3%–5%), sales and overhead (8%–12%).
Regional variation: Solar installation costs vary by up to 40% depending on location. California and Hawaii have higher labor costs ($3.50–$4.50/watt installed). Midwest and Southeast markets are more competitive ($2.50–$3.00/watt). The solar panel installation cost calculator uses your entered system cost — enter your installer’s quote for the most accurate results.
PV Solar Panel Calculator — System Sizing Guide
Correct system sizing prevents the two most common mistakes: undersizing (still paying significant electricity bills) and oversizing (producing more than you can use or export at good rates).
Step 1: Find your annual kWh usage Check your utility bill — most show last 12 months’ usage. National average: 10,500 kWh/year.
Step 2: Calculate required system size System size (kW) = Annual kWh ÷ (Daily sun hours × 365 × 0.80) 10,500 ÷ (5 × 365 × 0.80) = 7.19kW system for average US home at 5 sun hours
Step 3: Adjust for sun hours in your location
| Region | Average Daily Sun Hours |
|---|---|
| Southwest US (AZ, NV, NM) | 6.0–7.5 hrs |
| Southeast US (FL, TX, GA) | 5.0–6.0 hrs |
| Midwest US (IL, OH, MO) | 4.0–5.0 hrs |
| Northeast US (NY, MA, PA) | 3.5–4.5 hrs |
| Pacific Northwest (WA, OR) | 3.0–4.0 hrs |
| UK average | 2.5–3.5 hrs |
| Australia average | 4.5–6.5 hrs |
| Canada average | 3.0–5.0 hrs |
A Northeast home using 10,500 kWh/year at 4 sun hours needs: 10,500 ÷ (4 × 365 × 0.80) = 8.99kW system — larger than the same home in Arizona because less sun means lower production per kW.
How Many Solar Panels Do I Need Calculator
Panel Count Formula
Number of panels = System size in watts ÷ Panel wattage
Standard residential panels in 2026 range from 370W–430W. The market standard is moving toward 400W–420W panels.
9.5kW system ÷ 400W per panel = 23.75 → 24 panels 7kW system ÷ 400W per panel = 17.5 → 18 panels
Roof Space Required
Each standard 400W panel measures approximately 6.5 ft × 3.3 ft = 21.5 sq ft of mounting area. With standard racking spacing, allow approximately 22–25 sq ft per panel.
| Panel Count | Approximate Roof Space Needed |
|---|---|
| 12 panels | 264–300 sq ft |
| 18 panels | 396–450 sq ft |
| 24 panels | 528–600 sq ft |
| 30 panels | 660–750 sq ft |
Most suburban homes have 1,000–2,000 sq ft of total roof area. Usable south-facing area (in the northern hemisphere) is typically 30%–60% of total roof area after accounting for chimneys, vents, skylights, and shading.
When Your Roof Isn’t Big Enough
If roof space is limited, the solution is higher-efficiency panels (430W–450W now available) — fewer panels for the same system output at higher cost per panel. Alternatively, ground-mounted systems eliminate roof constraints entirely but require open land and typically cost 10%–20% more to install.
Are Solar Panels Worth It? — The Honest Answer by Situation
Best States for Solar ROI in 2026
The best states for solar ROI include Hawaii (highest electricity rates at 40+ cents/kWh), California, Massachusetts (SMART program plus high rates), New York (NY-Sun incentives plus high rates), and New Jersey (SREC market). For these states, payback periods of 4–7 years are common with lifetime savings exceeding $50,000.
Challenging states: Washington, Oregon, and Louisiana have low electricity rates from hydroelectric and fossil fuel sources — solar ROI is marginal without aggressive state incentives. In low-rate states, solar is now borderline without the federal credit, though state incentives like Massachusetts SMART, New York NY-Sun, and New Jersey TRECs survive.
Solar Panels Worth It — Break-Even by Electricity Rate
| Electricity Rate | 8kW System Payback | 25-Year Net Savings |
|---|---|---|
| $0.10/kWh (low, e.g. Louisiana) | 12–14 years | $8,000–$15,000 |
| $0.14/kWh (US average) | 8–10 years | $25,000–$40,000 |
| $0.20/kWh (moderate, e.g. Colorado) | 6–8 years | $45,000–$65,000 |
| $0.28/kWh (high, e.g. California) | 4–6 years | $70,000–$90,000 |
| $0.40/kWh (Hawaii) | 3–4 years | $100,000+ |
When Solar Is NOT Worth It
Solar is a poor financial decision when: your roof has less than 15 years of remaining life (re-roofing after installation costs $3,000–$8,000 in removal and reinstallation); your home is heavily shaded by large trees or adjacent buildings; you’re planning to sell within 3–4 years (you recoup value in the sale price, but not the full investment); your electricity rate is below $0.08/kWh; or your utility’s net metering policy pays only wholesale rates (2–4 cents/kWh) for excess generation.
The calculator’s payback period output makes this decision clear — if payback exceeds 15 years on a 25-year warranted system, the financial case is weak regardless of environmental benefits.
Solar Panel Tax Credit Calculator — Federal and International Incentives
US Federal Solar Tax Credit (ITC) — 2026 Status
The Section 25D residential solar Investment Tax Credit is 30% of total system cost through 2032, then steps down to 26% in 2033, 22% in 2034, and 0% for residential in 2035. This credit applies to the full installed cost including panels, inverter, racking, wiring, labor, and permits.
Key ITC rules:
- You must have federal tax liability to claim it — it’s a tax credit, not a refund
- Unused credit carries forward to future tax years
- Applies to primary and secondary residences
- Battery storage systems (with solar) also qualify for the 30% credit
- The credit is claimed on IRS Form 5695
On a $24,000 system: $7,200 credit. On a $36,000 system (larger home or with battery): $10,800 credit.
State Solar Incentives — Layered on Top of Federal ITC
Many states add their own incentives on top of the 30% federal credit:
New York: 25% state tax credit (up to $5,000) + NYSERDA rebates through NY-Sun program. Combined with federal ITC: effectively 50%+ of system cost offset.
Massachusetts: 15% state tax credit (up to $1,000) + SMART program performance incentives ($0.03–$0.10/kWh produced for 10 years). SMART alone can add $3,000–$8,000 in value on a typical system.
New Jersey: TRECs (Transition Renewable Energy Certificates) pay quarterly for 15 years. SRECs (Solar Renewable Energy Certificates) add additional revenue by selling solar production credits to utilities.
California: No state income tax credit, but the SGIP (Self-Generation Incentive Program) offers battery storage rebates up to $1,000/kWh.
Texas: No state income tax — ITC credit is relevant but the mechanism differs. Property tax exemption for solar: the added home value from solar installation is exempt from property tax assessment.
Check dsireusa.org for your specific state’s current programs — this database is maintained by NC State University and updated in real time.
UK Solar Incentives 2026
The UK removed the Feed-in Tariff (FiT) in 2019. Current UK incentives:
0% VAT on solar installation: Effectively reduces installation cost by 16.7% versus the previous 20% VAT rate. On a £8,000 system: £1,600 saved.
Smart Export Guarantee (SEG): UK homeowners with solar can sell surplus electricity to their energy supplier. Rates vary by supplier — Octopus Energy offers some of the highest SEG rates at 15p/kWh. Annual SEG income on a 4kW system: approximately £200–£400/year.
ECO4 Scheme: Low-income households may qualify for free or subsidized solar installation through the government’s Energy Company Obligation scheme.
AUS Solar Incentives 2026
Australia’s Small-scale Renewable Energy Scheme (SRES) creates Small-scale Technology Certificates (STCs) for solar installations. The number of STCs depends on system size, location (solar zone), and years remaining until the scheme ends (2030).
Typical STC value for a 6.6kW system in 2026: approximately A$2,500–A$4,500, typically claimed as an upfront discount from the installer. The calculator applies an estimated A$3,000 STC rebate by default for AUS systems — editable for your installer’s actual quote.
Canada Solar Incentives 2026
Canada Greener Homes Grant: Up to C$5,000 for solar PV systems ($1,000/kW up to 5kW, then $600/kW above 5kW). Requires a pre-installation EnerGuide home assessment.
Provincial programs: British Columbia offers the BC Hydro Net Metering program with full retail rate credit for surplus generation. Alberta’s ENMAX and other utilities offer net metering. Ontario’s Net Metering program allows rollover of credits for 12 months.
Solar Panel Savings Calculator — 25-Year Projection by Country
US — National Average Scenario
System: 8kW. Cost: $24,000. ITC: $7,200. Net cost: $16,800. Sun hours: 5/day. Rate: $0.14/kWh. Rate increase: 3%/year. Year 1 savings: $1,942. Payback: Year 9. 25-year total savings: $67,000. Net 25-year profit: $50,200.
High-rate scenario (California): Same system. Rate: $0.28/kWh. Year 1 savings: $3,884. Payback: Year 5. 25-year savings: $134,000. Net profit: $117,200.
UK — Typical Scenario
System: 4kW. Cost: £7,200 (after 0% VAT). Sun hours: 3/day. Rate: £0.28/kWh (2026 Ofgem cap average). Year 1 savings: £1,008. Payback: Year 8. SEG income: £250/year. Total 25-year value: £31,000.
AUS — Typical Scenario
System: 6.6kW. Cost: A$8,500 (after A$3,000 STC rebate). Sun hours: 5.5/day. Rate: A$0.32/kWh. Year 1 savings: A$3,297. Payback: Year 3. 25-year savings: A$115,000. Net profit: A$106,500. Australia has some of the fastest solar payback periods in the world — high electricity rates combined with excellent sun hours.
CAN — Typical Scenario
System: 7kW. Cost: C$22,000 (after C$5,000 Greener Homes Grant). Sun hours: 4/day. Rate: C$0.17/kWh. Year 1 savings: C$2,174. Payback: Year 8. 25-year savings: C$75,000. Net profit: C$58,000.
Solar Panel Angle Calculator — Optimizing Your System Output
What Is the Optimal Solar Panel Tilt Angle?
The optimal tilt angle for solar panels equals your latitude for maximum annual energy production. A home at 35° latitude (Dallas, TX) should tilt panels at approximately 35° from horizontal. At this angle, panels face the sun most directly during the year’s average sun position.
Tilt angle by location:
| Location | Latitude | Optimal Tilt |
|---|---|---|
| Miami, FL | 25.8° | 25°–26° |
| Dallas, TX | 32.8° | 33°–34° |
| Denver, CO | 39.7° | 40°–41° |
| Chicago, IL | 41.9° | 42°–43° |
| Seattle, WA | 47.6° | 48°–49° |
| London, UK | 51.5° | 51°–52° |
| Sydney, AUS | 33.9°S | 34° (facing north) |
| Toronto, CAN | 43.7° | 44°–45° |
In the southern hemisphere (Australia): panels face north (not south) to maximize sun exposure.
When Your Roof Angle Isn’t Optimal
Most residential roofs have a pitch of 20°–40°. Panels mounted flush to a south-facing 30° roof in Denver (optimal: 40°) lose approximately 1%–3% of annual output versus the optimal angle — a minimal difference that doesn’t justify costly racking adjustments. Adjustable racking that sets panels at the exact optimal angle adds cost but recovers efficiency primarily for flat-roof installations.
Azimuth (compass direction): South-facing is optimal in the northern hemisphere. Southwest or southeast-facing installations lose 10%–20% annual output compared to due south. East or west-facing installations lose 15%–25%.
Load-Based Solar Calculator — Size Your System From Appliances
Calculate System Size From Your Appliances
Rather than starting with your electricity bill, you can calculate required system size from the appliances you want to power. This is especially useful for new homes, off-grid systems, or EV charging additions.
How it works: Select each appliance, enter quantity and daily hours of use. The calculator sums your total daily watt-hour load and recommends the system size needed to cover it.
Common appliance loads:
| Appliance | Typical Wattage | Daily Hours | Daily kWh |
|---|---|---|---|
| Central AC (3 ton) | 3,500W | 6 hrs | 21.0 kWh |
| Central AC (2 ton) | 2,400W | 6 hrs | 14.4 kWh |
| Refrigerator | 150W | 24 hrs | 3.6 kWh |
| Electric water heater | 4,500W | 3 hrs | 13.5 kWh |
| Electric vehicle (Level 2) | 7,200W | 2 hrs | 14.4 kWh |
| Washer + dryer | 1,500W + 5,000W | 1 hr each | 6.5 kWh |
| LED lighting (home) | 300W | 6 hrs | 1.8 kWh |
| Pool pump | 1,500W | 6 hrs | 9.0 kWh |
A home with central AC, refrigerator, water heater, and basic lighting: approximately 40–50 kWh/day. At 5 sun hours and 80% efficiency: 40 kWh ÷ (5 × 0.80) = 10kW system required.
EV Charging and Solar — Sizing for Electric Vehicle Ownership
Adding an EV charging requirement is one of the most common reasons homeowners find their existing system undersized. A Tesla Model 3 driven 12,000 miles/year consumes approximately 4,320 kWh/year (36 kWh/100 miles). This requires an additional 1.5–2kW of solar capacity to offset completely.
If you’re sizing a new solar system with EV charging in mind, add 1.5kW–2kW to the system size that covers your home electricity use.
Battery Storage Add-On Calculator — Solar + Battery Economics
Why Add Battery Storage
Battery storage lets you use solar electricity you generate during the day at night — when your panels aren’t producing. Without battery storage, most homeowners export surplus midday production to the grid and buy electricity back in the evening.
In states with full retail net metering (credit for exports at the same rate as what you pay to import), battery storage has less financial benefit — the grid effectively acts as free storage. In states with reduced net metering compensation (NEM 3.0 in California pays approximately 5 cents/kWh for exports versus 28+ cents/kWh retail), battery storage dramatically improves economics.
Battery Storage Economics
A 10kWh home battery (Tesla Powerwall, Enphase IQ, Franklin WH) costs approximately $8,000–$12,000 installed before incentives. With the 30% federal ITC (batteries qualify when installed with solar): net cost $5,600–$8,400.
Annual value of battery storage in California (NEM 3.0) — storing 3,650 kWh annually that would otherwise be exported at 5 cents but is now used at retail 28 cents: savings = 3,650 × ($0.28 − $0.05) = $840/year in additional value. Payback on battery: $7,000 ÷ $840 = 8.3 years in addition to the solar payback.
For whole-home backup during outages: battery value is insurance beyond pure financial return — relevant in areas with frequent grid outages (Texas, California, Florida).
Real Solar Savings Scenarios With Actual Numbers
Scenario 1: Texas Homeowner — Average Sun, Average Rate
Home: 2,400 sq ft, $195/month electricity bill, Dallas TX (5.5 sun hours, $0.12/kWh). System: 8kW. Cost: $24,000. After 30% ITC: $16,800. Year 1 savings: $1,814. Payback: Year 10. 25-year savings: $62,000. Net profit: $45,200. CO2 offset: 10.5 tons/year. Panels needed: 20 × 400W panels. Roof space: 440 sq ft.
Texas electricity rates are below the national average — but rate volatility (February 2021 grid failure drove $16,000+ electricity bills for some customers) makes energy independence valuable beyond the financial math.
Scenario 2: California Homeowner — High Rate, High Sun
Home: 1,800 sq ft, $320/month electricity bill, San Jose CA (5.5 sun hours, $0.29/kWh). System: 9.5kW. Cost: $28,500. After 30% ITC: $19,950. Year 1 savings: $5,218 (NEM 3.0 reduces this — net approximately $3,800 with export at reduced rate). Payback: Year 6. 25-year savings: $132,000. Net profit: $112,000. Recommendation: Add 10kWh battery ($8,400 after ITC) to maximize self-consumption under NEM 3.0. Battery payback: approximately 7 years. Combined system net 25-year profit with battery: $119,000.
Scenario 3: UK Homeowner — Lower Sun, High Rate
Home: 3-bed semi-detached, £135/month electricity bill, Manchester UK (3 sun hours, £0.25/kWh). System: 4kW. Cost: £7,200 (after 0% VAT savings). Sun hours: 3/day. Year 1 savings: £876. SEG export income: £180. Total Year 1 value: £1,056. Payback: Year 8. 25-year total value: £36,500.
Scenario 4: Australian Homeowner — Excellent ROI
Home: 4-bed house, A$220/month electricity bill, Brisbane AUS (6 sun hours, A$0.30/kWh). System: 6.6kW. Cost: A$8,500 (after A$3,000 STC rebate). Sun hours: 6/day. Year 1 savings: A$4,277. Payback: Year 2. 25-year savings: A$148,000. Net profit: A$139,500. Australia has among the best solar economics globally — high sunshine, high electricity rates, and government rebates combine for payback periods as short as 2–3 years in Queensland and South Australia.
Frequently Asked Questions
What is a solar panel calculator?
A solar panel calculator estimates your annual savings, payback period, 25-year ROI, required panel count, and federal tax credit amount based on your system size, electricity bill, sun hours, and location. A complete solar panel calculator also shows CO2 offset, net metering value, and the exact year your system pays for itself.
How do I calculate solar panel savings?
Annual savings = Annual solar production (kWh) × Electricity rate per kWh. Annual production = System size (kW) × Daily sun hours × 365 × 0.80 (efficiency factor). On a 9.5kW system at 5 sun hours and $0.14/kWh: 9.5 × 5 × 365 × 0.80 × $0.14 = $1,942/year. At California’s $0.28/kWh: $3,884/year.
How many solar panels do I need for my home?
System size = Annual kWh usage ÷ (Daily sun hours × 365 × 0.80). The average US home uses 10,500 kWh/year. At 5 sun hours: 10,500 ÷ (5 × 365 × 0.80) = 7.2kW system. At 400W per panel: 18 panels. Homes in low-sun regions (Northeast, UK, Pacific Northwest) need proportionally larger systems for the same output.
What is the solar panel federal tax credit in 2026?
The US Section 25D Investment Tax Credit is 30% of the total installed system cost through 2032. On a $24,000 system: $7,200 credit against your federal income tax liability. The credit applies to panels, inverter, racking, wiring, labor, permits, and battery storage when installed with solar.
How long is the payback period for solar panels?
The average solar panel payback period in the US is 7–10 years on a national basis. In high-electricity-rate states (California, Hawaii, Massachusetts): 4–7 years. In low-rate states (Washington, Louisiana): 10–14 years. In Australia: 2–4 years. In the UK: 7–10 years. After payback, every kWh produced is pure savings for the remaining panel life.
Are solar panels worth it in 2026?
For most homeowners in the US, UK, Australia, and Canada — yes. An 8kW system costs about $24,800 installed, saves $1,500–$4,500 per year depending on your electricity rate, and pays for itself in 6–13 years. After payback, you get 12–19 years of essentially free electricity. Over 25 years, net savings range from $12,000 in low-rate states to $75,000+ in Hawaii. The annual return on investment of 8%–20% outperforms most traditional investments.
What is net metering and how does it affect solar savings?
Net metering allows solar homeowners to export surplus electricity to the grid and receive credits against their bill. Full retail net metering (most US states) means you get credited at the same rate you pay — effectively using the grid as free battery storage. California’s NEM 3.0 (2023+) reduced export credits to approximately 5 cents/kWh — significantly reducing the value of daytime surplus generation and making battery storage more attractive.
How much CO2 does a solar system offset?
A 9.5kW solar system producing approximately 13,870 kWh/year offsets approximately 5.4 metric tons of CO2 annually (using EPA’s 2026 US average grid emission factor of 0.386 kg CO2 per kWh). This is equivalent to planting approximately 250 trees per year or removing 1.2 cars from the road. The offset varies by location — solar in coal-heavy grid regions (Ohio, Indiana) offsets more CO2 per kWh than solar in clean-grid states (Washington, Vermont).
Data Sources
Accuracy & Verification
US solar installation costs ($2.75–$3.25/watt) from NREL (National Renewable Energy Laboratory) Q3 2025 Solar Cost Benchmark. US average electricity rate ($0.144/kWh) from EIA Electric Power Monthly, April 2026. Federal ITC (30% through 2032) from IRS Notice 2023-29 and IRC Section 25D. State incentive programs from DSIRE (Database of State Incentives for Renewables and Efficiency), April 2026. Panel degradation rate (0.5%/year) from Jordan & Kurtz (2013) NREL meta-analysis, validated against NREL PVDAQ field data. UK electricity rates and SEG data from Ofgem 2026 Q1 price cap. AUS STC values from Australian Clean Energy Regulator 2026. CAN Greener Homes Grant from Natural Resources Canada program documentation. CO2 emission factors from EPA eGRID 2023 Summary. Last verified: April 2026.
This tool provides estimates for planning and comparison purposes only. Actual solar system performance, cost, and savings depend on your specific roof characteristics, shading, local utility rates and billing structure, equipment selection, installer pricing, and applicable incentives at time of installation. Consult a licensed solar installer for site-specific analysis.
Related Calculators
Tools That Connect to This One
Understanding solar savings is one part of the home energy financial picture. The mortgage calculator shows how adding solar financing to a home purchase affects your total monthly payment. For homeowners using home equity to finance solar installation, the HELOC calculator models the borrowing cost versus direct loan financing. And to see the full financial impact of solar on your property’s net worth, the net worth calculator maps the system as an asset against all liabilities.