Home Solar FAQ: 40 Questions Homeowners Actually Ask

This home solar FAQ gives short, sourced answers to the 40 questions we see most, each linking to a deeper guide in our Home Solar series. Are solar panels worth it? That’s the question behind most solar threads on Reddit and homeowner forums. The honest answer depends on your electric rates, sun, roof and how you pay.

Home Solar FAQ: Cost and Payback

Are solar panels worth it in 2026? Often, where rates are high and sun is good. Run the numbers on your bill.
What does solar cost? Berkeley Lab’s 2024 median was about $4.0/W installed.
Is there still a federal tax credit? Not 25D for homeowner-owned systems after 2025.
What’s a typical payback? Commonly 7-15 years without the federal credit; it varies widely.
Cash, loan or lease? Cash usually costs least overall. Watch loan dealer fees.
Do leases still get a credit? The leasing company may claim 48E.
Does solar raise home value? Owned systems often do; leases less so.
Are there state incentives? Check DSIRE.

Sizing

How many panels do I need? Annual kWh ÷ PVWatts kWh per kW ÷ panel watts.
How much roof space? About 20-23 sq ft per 400W panel.
Does roof direction matter? South is best; east-west works with some loss.
Should I size for an EV? Yes, if you’ll have one soon.
What about shade? It cuts output; microinverters or optimizers help.

Net Metering and Rates

What is net metering? Exports credited at or near retail.
What is NEM 3.0? California’s net billing; exports earn much less.
What is TOU? Prices that change by time of day.
Can solar zero my bill? Usually not fixed charges.

Batteries

Do I need a battery? Not for savings under net metering; yes for backup.
Will solar work in a blackout? Not without a battery or backup-capable inverter.
How long does a battery last in an outage? Usable kWh ÷ average load.
Which chemistry? Most home batteries use LiFePO4.
How long do batteries last? Warranties are often 10-15 years.
Can I add a battery later? Usually, via AC coupling.
Whole-home or critical loads? Critical loads costs less.

Equipment

Microinverters or string? Micros handle shade; strings cost less.
Which panels are best? Compare warranty, efficiency and temperature coefficient.
How long do panels last? 25-30+ years.
How fast do they degrade? About 0.5% a year (NREL median).
Do they work when cloudy? Yes, at reduced output.
Do they need cleaning? Only if soiling cuts output.

Install and Roof

How long does install take? 1-3 days; the whole process 1-4 months.
Should I replace my roof first? If it has under about 10 years left.
Will panels cause leaks? Rare with proper flashing.
Fire risk? Low; codes require rapid shutdown.
Can I DIY? Often legally, with permits and inspection.
How do I choose an installer? Three quotes, license, NABCEP, cash price.

Living With Solar

What maintenance is needed? Monitor production; inspect occasionally.
What if I sell? Owned transfers with the home; leases need transfer or buyout.
Does hail break panels? Most are hail-tested; check insurance.
What’s the biggest mistake? Signing fast without comparing quotes.

Worked Example: Are Solar Panels Worth It for You?

Here’s the quickest way to answer the FAQ’s top question, using an illustrative home that uses 10,500 kWh a year (EIA’s 2023 U.S. average) and 1,350 kWh per kW of output.

Step	Math	Result
System size	10,500 ÷ 1,350	about 7.8 kW (20 panels at 400 W)
Cost at LBNL 2024 median	7.8 × $4,000	about $31,200
Year-1 savings at EIA 2024 avg (16.5¢)	10,500 × $0.165	about $1,733
Simple payback	$31,200 ÷ $1,733	about 18 years
Year-1 savings at 30¢	10,500 × $0.30	$3,150
Simple payback at 30¢	$31,200 ÷ $3,150	about 9.9 years

The same system can pay back in under 10 years or close to 20, depending mostly on your rate and price per watt. Paying cash (LBNL median $3.5/W) lowers the cost to about $27,300. See are solar panels worth it in 2026 and solar payback period.

The Top Solar FAQs, Answered in More Depth

The quick answers above cover the basics. These six questions come up most often, so here’s a fuller answer for each, with the numbers behind it.

Are solar panels worth it without the federal tax credit?

Often, yes, but the margin is thinner. The 30% Residential Clean Energy Credit (25D) no longer applies to homeowner-owned systems installed after December 31, 2025, according to the IRS. That pushes simple payback out by a few years. The biggest drivers now are your electricity rate, your installed price per watt and how your utility credits exports. Homes paying 25–30¢ per kWh or more can still see payback in about a decade, as the worked example below shows.

How much do solar panels cost for a typical home?

Berkeley Lab’s Tracking the Sun puts the 2024 median residential price at about $4.0 per watt, with most systems between $3.0 and $5.2 per watt. For a 7.8kW system sized to the average U.S. home, that’s roughly $23,000–$41,000, with the median around $31,000. Getting three quotes and comparing the cash price per watt is the most reliable way to land toward the low end.

What changed with NEM 3.0 and net billing?

Under classic net metering, each exported kWh earns about the retail rate. California’s net billing tariff, often called NEM 3.0, took effect for new applications in April 2023 and credits exports at much lower, time-varying values. Under rules like that, the value of solar shifts toward using your own power when it’s produced, and a battery becomes more useful for moving daytime solar into the evening. Other states set their own rules, so check your utility’s current tariff.

How long will a home battery last in an outage?

Divide usable battery kWh by your average load. A Tesla Powerwall 3 stores 13.5kWh, per Tesla. At an average of 1.2kW (fridge, lights, internet, a few outlets), that’s about 11 hours without solar, and solar can recharge it during the day. Whole-home loads like central AC or an electric range shorten that a lot, which is why many homes back up a critical-loads panel.

Average load	What it covers	13.5kWh battery runtime (no solar)
500W	Fridge, router, LED lights, phones	~27 hours
1.2kW	Add TV, microwave use, a few outlets	~11 hours
3kW	Add a window or mini-split AC	~4.5 hours
5kW+	Central AC, well pump, cooking	Under 3 hours

Our estimates using Tesla’s 13.5kWh rated capacity. See home battery backup for a power outage.

How long do solar panels last?

Most panels carry 25-year power warranties, and many keep producing well beyond that. NREL’s median degradation rate is about 0.5% per year, so a panel would still produce roughly 87–88% of its original output after 25 years. Inverters usually need replacing sooner than panels, often within 10–15 years for string inverters, while microinverters typically carry 25-year warranties. See solar panel degradation per year.

Can I add solar or a battery later?

Yes. Many homeowners start with panels and add a battery later through AC coupling, which connects the battery on the AC side without replacing the solar inverter. Adding more panels later is possible too, but it’s simpler to size for future needs, like an EV or heat pump, from the start.

Home Solar Glossary

Term	Meaning
kW (kilowatt)	Power, or the size of a system. A 7kW system produces up to about 7kW in full sun.
kWh (kilowatt-hour)	Energy, which is what your bill charges for. See what is a kilowatt-hour.
Peak sun hours	Hours of sunlight equal to 1,000W per square meter. Used for output estimates.
PVWatts	NREL’s free calculator that estimates yearly output for your address
Net metering	Exports credited at or near the retail rate
Net billing	Exports credited at a lower, often time-varying rate
TOU (time of use)	Electricity rates that change by time of day
Microinverter	A small inverter on each panel
String inverter	One inverter for a whole series string of panels
Rapid shutdown	A code requirement that lowers rooftop conductor voltage quickly in an emergency
AC coupling	Adding a battery on the AC side of an existing solar system
NABCEP	A widely recognized certification for solar installers

Definitions summarized from DOE and NREL resources.

Key Numbers at a Glance

Number	Value	Source
Median installed price, 2024	about $4.0/W	Berkeley Lab
Typical price range (20th–80th percentile)	$3.0–$5.2/W	Berkeley Lab
Average home use, 2023	about 10,500 kWh a year	EIA
Average residential price, 2024	about 16.5¢/kWh	EIA
Median panel degradation	about 0.5% a year	NREL
PVWatts default system losses	14%	NREL
Federal 25D credit	Ended for systems installed after 2025	IRS

Step-by-Step: Your First Week of Solar Research

Gather 12 months of bills. See reading your electric bill before solar.
Run PVWatts for your address.
Size a system with how many solar panels do I need.
Check your utility’s export rules.
Look up incentives on DSIRE.
Get three quotes and compare cash $/W.
Decide on batteries with is a solar battery worth it.

FAQ

How long will a solar battery last during a power outage?

Usable kWh divided by your average load. A 13.5kWh battery runs about 11 hours at 1.2kW without solar.

Do solar panels still work after 25 years?

Usually. At NREL’s median 0.5% yearly degradation, panels keep about 87–88% of their original output after 25 years.

So, are solar panels worth it?

For many homeowners with high rates and good sun, yes. Compare quotes and payback.

Where should I start if I’m new to solar?

Start with your yearly kWh and electric rate, then run PVWatts. Our home solar battery guide links every topic in order.

Is there still a federal solar tax credit in 2026?

Not for homeowner-owned systems: the 25D credit ended for systems installed after December 31, 2025. Leasing companies may still claim 48E. See solar tax credit 2026.

How much do solar panels cost per watt?

Berkeley Lab’s 2024 median was about $4.0/W, with most systems between $3.0 and $5.2/W. See how much do solar panels cost.

Sources: U.S. DOE, “Homeowner’s Guide to Going Solar” and “Solar Financing”; IRS Residential Clean Energy Credit; Lawrence Berkeley National Laboratory, Tracking the Sun (2025 update); NREL; EIA; NREL PVWatts; DSIRE. Accessed Oct 2026.