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Rooftop solar has never been more affordable. Here's everything you need to know about going solar in 2025.
SOLAR COSTS 2025
Average system (6kW): Before incentives: $15,000-$18,000 After 30% federal tax credit: $10,500-$12,600 Cost per watt: $2.50-$3.00
Cost factors: System size (kW) Panel quality/efficiency Roof complexity Location (permitting costs vary) Installer (local vs. national)
FEDERAL TAX CREDIT
30% of total system cost (extended through 2032) Includes: Panels, inverter, installation, battery (if added) Requirements: You owe federal taxes, own your home How it works: Reduces tax bill dollar-for-dollar, can carry forward if credit exceeds tax owed
Example: $18,000 system → $5,400 tax credit → Net cost $12,600
STATE/LOCAL INCENTIVES
Check Database of State Incentives for Renewables & Efficiency (DSIRE): dsireusa.org
Common incentives: State tax credits Utility rebates ($0.10-0.50/watt) Property tax exemptions Sales tax exemptions Performance-based incentives (paid per kWh generated)
Best states: California, New York, Massachusetts, New Jersey, Arizona
NET METERING
Sell excess solar electricity back to utility at retail rate Your meter runs backward when producing more than using Bank credits for nighttime/cloudy days Available in 40+ states Critical for solar economics
PAYBACK PERIOD
Formula: Net cost ÷ Annual savings = Years to payback
Example: System cost after incentives: $12,000 Annual electric savings: $1,500 Payback: 8 years
Factors affecting payback: Electric rates (higher = faster payback) Sun exposure (5+ peak sun hours ideal) System size vs. usage Incentives available Net metering policy
Average payback: 7-12 years System lifespan: 25-30 years Profit years: 13-23 years of free electricity
SOLAR PANELS
Types: Monocrystalline: Most efficient (19-22%), pricey, best for limited space Polycrystalline: Mid-efficiency (15-17%), cheaper Thin-film: Least efficient (10-13%), cheapest, flexible
Top brands: Premium: SunPower (22%+ efficiency), LG, Panasonic Mid-tier: Canadian Solar, Trina, Jinko Budget: Many Chinese manufacturers
Warranties: Performance: 25 years (80-90% output guaranteed) Product: 10-25 years (manufacturing defects) Workmanship: 5-10 years (installation)
INVERTERS
Convert DC (solar panels) to AC (home electricity)
String inverter: One central unit for entire array Cheapest option Whole system affected by shade on one panel Typical choice for unshaded roofs
Microinverters: One per panel Better performance with partial shade Individual panel monitoring Slightly more expensive Brands: Enphase (most popular), SolarEdge
Power optimizers: Middle option (optimizers on panels, central inverter) Good shade tolerance Panel-level monitoring
BATTERY STORAGE
Popular options: Tesla Powerwall 2: 13.5 kWh, $11,000 installed LG Chem RESU: 9.8-16 kWh, $9,000-13,000 Enphase IQ: Modular, $10,000+ for 10kWh
Benefits: Backup power during outages Time-of-use arbitrage (charge off-peak, discharge on-peak) Energy independence Maximize solar self-consumption
Is battery worth it? Depends on: Frequency of outages, time-of-use rates, net metering policy, cost of peace of mind
Rule of thumb: Battery adds 50-100% to system cost, 10+ year payback
SIZING YOUR SYSTEM
Step 1: Annual electricity use (check bills) Example: 10,000 kWh/year
Step 2: Peak sun hours in your area Check PVWatts calculator (pvwatts.nrel.gov) Example: 5 hours/day average
Step 3: System size needed 10,000 kWh ÷ 365 days ÷ 5 sun hours ÷ 0.75 (efficiency factor) = 7.3 kW system
Typical home: 5-10 kW system
ROOF REQUIREMENTS
Age: 10+ years remaining life Condition: No repairs needed Space: 100 sq ft per kW (~600-1,000 sq ft total) Direction: South ideal, east/west ok, north worst (Northern hemisphere) Pitch: 15-40 degrees ideal Shade: Minimal (trees, chimneys, neighboring buildings)
What if roof isn't ideal? Ground mount (if you have land) Community solar (subscribe to remote array) Wait for roof replacement
GROUND MOUNT
When to consider: Shaded roof Roof facing wrong direction HOA restricts roof installation Insufficient roof space Combining solar with carport/pergola
Cost: 10-20% more than roof mount Benefits: Optimal angle/orientation, easier maintenance, expandable
INSTALLATION PROCESS
Timeline: 1-3 months total
Steps:
CHOOSING INSTALLER
Get quotes from: National: Tesla, SunRun, Sungevity Regional/local: Often better service, competitive price
Compare: Price per watt Equipment brands Warranties Reviews (Yelp, Google, BBB) Years in business Certifications (NABCEP)
Red flags: Pressure tactics Deal "expires today" Price way below competitors Can't explain equipment choices
FINANCING OPTIONS
Cash: Best ROI Immediate 30% tax credit benefit No interest
Loan: $0 down solar loans common Rates: 3-7% typical Tax credit can pay chunk of loan Own system (can claim incentives)
Lease/PPA: $0 down, $0 upfront cost Pay monthly fee or per kWh Installer owns system (they get incentives) Savings: 10-30% vs. utility typically Good if: Don't have tax liability, don't want to own
SALES PRESSURE TACTICS
Beware: "Tax credit expires soon" (it doesn't, through 2032) "Last day of discount" "Prices going up tomorrow" "Free solar" (leases aren't free)
Take your time: Get multiple quotes, read contracts carefully
MONITORING
Most systems include monitoring app Track: Daily/monthly production, lifetime savings, carbon offset, panel performance
Apps: Enphase Enlighten (microinverters) SolarEdge monitoring Tesla app (Powerwall)
MAINTENANCE
Good news: Very low maintenance
Occasional: Visual inspection (cracks, debris) Clean panels if dusty/dirty (rain usually sufficient) Trim overhanging branches Inverter may need replacement (10-15 years)
Cost: <$100/year typically
ENVIRONMENTAL IMPACT
Average 6kW system: Offsets: 7,500 lbs CO2/year (equivalent to planting 90 trees annually) Over 25 years: 187,500 lbs CO2 Equivalent to: Taking 2 cars off road for 25 years
Energy payback: 1-4 years (energy to manufacture paid back)
COMMON CONCERNS
"Panels ugly?" - Newer panels sleeker, all-black options "Damage roof?" - Proper install protects roof, warranty covers damage "What if I move?" - Solar increases home value, often recoups cost, or take system with you "Hail damage?" - Panels tested for 1" hail at 50 mph, covered by homeowners insurance "Panel disposal?" - 95% recyclable, industry building recycling infrastructure
PROPERTY VALUE
Studies show: $15,000 value increase for average system (Zillow, Lawrence Berkeley Lab) Rule of thumb: $4 added value per watt installed Example: 6kW system adds $24,000 to home value
COMMUNITY SOLAR
Can't install rooftop solar? Subscribe to local solar farm.
How it works: Subscribe to portion of community array Receive credits on electric bill No installation, no upfront cost Savings: 5-15% typically
Check: communitysolar.org for programs in your area
RESOURCES
Calculators: PVWatts (NREL): pvwatts.nrel.gov Google Project Sunroof: sunroof.withgoogle.com EnergySage calculator: energysage.com/solar-calculator
Quotes: EnergySage (compare installers): energysage.com PickMySolar: pickmysolar.com
Information: Solar Energy Industries Association: seia.org NREL solar resources: nrel.gov/solar Database of incentives: dsireusa.org
DISCUSSION
Do you have solar? What's been your experience? Considering solar? What's holding you back? Questions about installation or economics?
SOLAR COSTS 2025
Average system (6kW): Before incentives: $15,000-$18,000 After 30% federal tax credit: $10,500-$12,600 Cost per watt: $2.50-$3.00
Cost factors: System size (kW) Panel quality/efficiency Roof complexity Location (permitting costs vary) Installer (local vs. national)
FEDERAL TAX CREDIT
30% of total system cost (extended through 2032) Includes: Panels, inverter, installation, battery (if added) Requirements: You owe federal taxes, own your home How it works: Reduces tax bill dollar-for-dollar, can carry forward if credit exceeds tax owed
Example: $18,000 system → $5,400 tax credit → Net cost $12,600
STATE/LOCAL INCENTIVES
Check Database of State Incentives for Renewables & Efficiency (DSIRE): dsireusa.org
Common incentives: State tax credits Utility rebates ($0.10-0.50/watt) Property tax exemptions Sales tax exemptions Performance-based incentives (paid per kWh generated)
Best states: California, New York, Massachusetts, New Jersey, Arizona
NET METERING
Sell excess solar electricity back to utility at retail rate Your meter runs backward when producing more than using Bank credits for nighttime/cloudy days Available in 40+ states Critical for solar economics
PAYBACK PERIOD
Formula: Net cost ÷ Annual savings = Years to payback
Example: System cost after incentives: $12,000 Annual electric savings: $1,500 Payback: 8 years
Factors affecting payback: Electric rates (higher = faster payback) Sun exposure (5+ peak sun hours ideal) System size vs. usage Incentives available Net metering policy
Average payback: 7-12 years System lifespan: 25-30 years Profit years: 13-23 years of free electricity
SOLAR PANELS
Types: Monocrystalline: Most efficient (19-22%), pricey, best for limited space Polycrystalline: Mid-efficiency (15-17%), cheaper Thin-film: Least efficient (10-13%), cheapest, flexible
Top brands: Premium: SunPower (22%+ efficiency), LG, Panasonic Mid-tier: Canadian Solar, Trina, Jinko Budget: Many Chinese manufacturers
Warranties: Performance: 25 years (80-90% output guaranteed) Product: 10-25 years (manufacturing defects) Workmanship: 5-10 years (installation)
INVERTERS
Convert DC (solar panels) to AC (home electricity)
String inverter: One central unit for entire array Cheapest option Whole system affected by shade on one panel Typical choice for unshaded roofs
Microinverters: One per panel Better performance with partial shade Individual panel monitoring Slightly more expensive Brands: Enphase (most popular), SolarEdge
Power optimizers: Middle option (optimizers on panels, central inverter) Good shade tolerance Panel-level monitoring
BATTERY STORAGE
Popular options: Tesla Powerwall 2: 13.5 kWh, $11,000 installed LG Chem RESU: 9.8-16 kWh, $9,000-13,000 Enphase IQ: Modular, $10,000+ for 10kWh
Benefits: Backup power during outages Time-of-use arbitrage (charge off-peak, discharge on-peak) Energy independence Maximize solar self-consumption
Is battery worth it? Depends on: Frequency of outages, time-of-use rates, net metering policy, cost of peace of mind
Rule of thumb: Battery adds 50-100% to system cost, 10+ year payback
SIZING YOUR SYSTEM
Step 1: Annual electricity use (check bills) Example: 10,000 kWh/year
Step 2: Peak sun hours in your area Check PVWatts calculator (pvwatts.nrel.gov) Example: 5 hours/day average
Step 3: System size needed 10,000 kWh ÷ 365 days ÷ 5 sun hours ÷ 0.75 (efficiency factor) = 7.3 kW system
Typical home: 5-10 kW system
ROOF REQUIREMENTS
Age: 10+ years remaining life Condition: No repairs needed Space: 100 sq ft per kW (~600-1,000 sq ft total) Direction: South ideal, east/west ok, north worst (Northern hemisphere) Pitch: 15-40 degrees ideal Shade: Minimal (trees, chimneys, neighboring buildings)
What if roof isn't ideal? Ground mount (if you have land) Community solar (subscribe to remote array) Wait for roof replacement
GROUND MOUNT
When to consider: Shaded roof Roof facing wrong direction HOA restricts roof installation Insufficient roof space Combining solar with carport/pergola
Cost: 10-20% more than roof mount Benefits: Optimal angle/orientation, easier maintenance, expandable
INSTALLATION PROCESS
Timeline: 1-3 months total
Steps:
- Quotes from 3+ installers (2-4 weeks)
- Choose installer, finalize design (1 week)
- Permitting (2-6 weeks, varies by locality)
- Installation (1-3 days)
- Inspection (1-2 weeks)
- Permission to operate from utility (1-4 weeks)
- System live!
CHOOSING INSTALLER
Get quotes from: National: Tesla, SunRun, Sungevity Regional/local: Often better service, competitive price
Compare: Price per watt Equipment brands Warranties Reviews (Yelp, Google, BBB) Years in business Certifications (NABCEP)
Red flags: Pressure tactics Deal "expires today" Price way below competitors Can't explain equipment choices
FINANCING OPTIONS
Cash: Best ROI Immediate 30% tax credit benefit No interest
Loan: $0 down solar loans common Rates: 3-7% typical Tax credit can pay chunk of loan Own system (can claim incentives)
Lease/PPA: $0 down, $0 upfront cost Pay monthly fee or per kWh Installer owns system (they get incentives) Savings: 10-30% vs. utility typically Good if: Don't have tax liability, don't want to own
SALES PRESSURE TACTICS
Beware: "Tax credit expires soon" (it doesn't, through 2032) "Last day of discount" "Prices going up tomorrow" "Free solar" (leases aren't free)
Take your time: Get multiple quotes, read contracts carefully
MONITORING
Most systems include monitoring app Track: Daily/monthly production, lifetime savings, carbon offset, panel performance
Apps: Enphase Enlighten (microinverters) SolarEdge monitoring Tesla app (Powerwall)
MAINTENANCE
Good news: Very low maintenance
Occasional: Visual inspection (cracks, debris) Clean panels if dusty/dirty (rain usually sufficient) Trim overhanging branches Inverter may need replacement (10-15 years)
Cost: <$100/year typically
ENVIRONMENTAL IMPACT
Average 6kW system: Offsets: 7,500 lbs CO2/year (equivalent to planting 90 trees annually) Over 25 years: 187,500 lbs CO2 Equivalent to: Taking 2 cars off road for 25 years
Energy payback: 1-4 years (energy to manufacture paid back)
COMMON CONCERNS
"Panels ugly?" - Newer panels sleeker, all-black options "Damage roof?" - Proper install protects roof, warranty covers damage "What if I move?" - Solar increases home value, often recoups cost, or take system with you "Hail damage?" - Panels tested for 1" hail at 50 mph, covered by homeowners insurance "Panel disposal?" - 95% recyclable, industry building recycling infrastructure
PROPERTY VALUE
Studies show: $15,000 value increase for average system (Zillow, Lawrence Berkeley Lab) Rule of thumb: $4 added value per watt installed Example: 6kW system adds $24,000 to home value
COMMUNITY SOLAR
Can't install rooftop solar? Subscribe to local solar farm.
How it works: Subscribe to portion of community array Receive credits on electric bill No installation, no upfront cost Savings: 5-15% typically
Check: communitysolar.org for programs in your area
RESOURCES
Calculators: PVWatts (NREL): pvwatts.nrel.gov Google Project Sunroof: sunroof.withgoogle.com EnergySage calculator: energysage.com/solar-calculator
Quotes: EnergySage (compare installers): energysage.com PickMySolar: pickmysolar.com
Information: Solar Energy Industries Association: seia.org NREL solar resources: nrel.gov/solar Database of incentives: dsireusa.org
DISCUSSION
Do you have solar? What's been your experience? Considering solar? What's holding you back? Questions about installation or economics?