This guide walks you through every decision in a solar purchase: which panel type fits your roof, how many panels you need, what a system costs, and which brands and installers deserve your money. By the end you can request quotes with real numbers instead of guesses. Solar isn't best for everyone, so the guide also flags the situations where the right call is to wait.
PowerOutage.us logged 1.8 million site requests per hour when Hurricane Milton made landfall in October 2024. That outage record anchors our buying guidance, so you size and select panels that carry your home through a real outage.
Should you buy solar panels at all?
Buy solar when you own the roof, plan to stay 7 to 10 years, and pay electricity rates high enough for the savings to repay the system. A solar array cuts your electricity bill, moves you toward energy independence, and shrinks your carbon footprint, but only when your roof, budget, and length of ownership support it. Renters, owners of heavily shaded roofs, and anyone moving within a few years should run the payback math.
If solar clears that bar for you, the rest of this guide covers the decisions in order: panel specs, panel type, system size, installation options, total cost, brand, and installer.
The four specs that decide which panel to buy
Four numbers separate one solar panel from another, and all four appear on every spec sheet:
- Wattage (rated power output): Residential panels deliver 300 W to 450 W per unit. Panels below that range force you to buy more of them for the same output.
- Efficiency percentage: Efficiency measures how much sunlight the panel converts to electricity. A higher percentage means more power per square foot of roof.
- Temperature coefficient: This number states how much output drops per degree Celsius above 25 °C. The lower the number, the better the panel performs in heat.
- Performance degradation: Panels lose 0.3% to 0.8% of output per year across a 25 to 30 year life. Pick the lowest degradation rate you can afford; it compounds over decades.
Which solar panel type fits your home?
Monocrystalline, polycrystalline, and thin-film panels serve three different buyers, so match the type to your roof space and budget before comparing brands.
Monocrystalline silicon (Mono-Si)
Monocrystalline panels are the right buy for most rooftops, and they dominate residential installations. Each cell is cut from a single silicon crystal, so electrons flow freely and efficiency reaches 18% to 23%. Monocrystalline solar panels also pack the most output into the smallest footprint, which makes them the pick for limited roof space or premium systems.
Polycrystalline silicon (Poly-Si)
Polycrystalline panels trade efficiency for price. Multiple silicon fragments in each cell constrain electron movement, so efficiency lands between 15% and 18% and the array needs more roof area for the same output. Polycrystalline solar panels cost less per panel, which suits budget-driven installations on large, unshaded roofs.
Thin-film panels (CdTe, CIGS, a-Si)
Thin-film panels convert 10% to 13% of sunlight, the lowest of the three types, but they cost the least to manufacture and weigh far less. The three varieties are amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium selenide (CIGS), with CdTe the most common. Buy thin-film solar panels for large commercial arrays, RVs, or off-grid structures, not for a house roof where space is money.
How many panels and what size system do you need?
System size comes from three numbers: your daily electricity use, your area's peak sun hours, and a margin. Work through them in order, and check our guides to solar panel size and the number of solar panels a home needs for examples.
Daily electricity use
Start with your daily use in kilowatt hours (kWh). Your electric bill lists total kWh in its summary section. Divide the monthly figure by 30 and you have the daily target your array must produce.
Peak sun hours
Peak sun hours state how much usable sunlight your location receives. A peak sun hour is any hour when solar irradiance averages 1,000 watts per square meter. Most US locations receive three to six peak sun hours a day. More sun hours mean each panel produces more, so a sunnier location buys you a smaller, cheaper system.
Array size
Divide your daily kWh use by your area's peak sun hours, then multiply by 1.2. The result is the array size in kW that covers your use plus a 20% margin for efficiency losses and future load growth.
Battery storage compatibility
A battery stores your surplus production for night use and outages. Lithium-based batteries run reliably but raise upfront cost, so confirm which batteries pair with your panels and inverter before you buy either. Installers can match chemistry, capacity, and budget to your system design.
Installation choices that change your quote
Mounting location, inverter type, and monitoring hardware each move your quote by thousands of dollars, so decide them before you compare bids.
Roof mount or ground mount
Roof mounting costs less; ground mounting produces more flexibly.
Roof-mounted solar panels
Pros
- Installation is less labor-intensive and less expensive
- The permitting process is relatively simple
- Fewer materials needed for installation
Cons
- May need additional reinforcements
- Roof space constrains the size of the system
- You may have to reinstall the system if the roof needs replacement
Ground-mounted solar panels
Pros
- Flexible orientation
- Easy to access and clean
- Cooler panel temperature and thus higher energy output
Cons
- Installation is more labor-intensive and expensive
- More costly and complicated permitting process
- May reduce curb appeal
String inverter or microinverters
The solar inverter converts the DC electricity your panels generate into the AC electricity your home runs on, and the type you pick decides how shading affects the whole array:
- String inverters install near your main service panel and control the system from one central box. They cost the least and perform best on unshaded roofs.
- Microinverters mount on the back of each panel, so one shaded panel no longer drags down the rest. They fit complex or partially shaded roofs.
- Power optimizers split the difference: panel-level electronics feed a central string inverter, adding per-panel control at a middle price.
Monitoring systems
A monitoring system reports your production in real time through a mobile app or web dashboard. Manufacturers, installers, and third-party companies all sell them; confirm yours shows per-panel output so you catch a failing panel early.
Smart meters and grid tie-in
A grid-tied system needs a smart meter to record every watt you send back and to run accurate net metering credits. Off-grid systems skip the smart meter entirely.
What you'll actually pay for solar
A 5 kW system averages $17,823 installed in the US, based on our solar panel cost data. Arizona posts the lowest state average at $13,958; Hawaii posts the highest at $21,082. Price per watt averages $3.56 nationally, ranging from $2.79 to $4.22.
Payback averages 10 years nationwide. Several states repay in seven years, while New Mexico takes 16. Twenty-year savings average $17,166 per household, from a low of $4,409 in New Mexico to a high of $32,080 in Connecticut.
The 30% federal residential solar tax credit expired at the end of 2025, so the figures above reflect what buyers now pay without it. Check state and utility rebates, which still cut costs in many markets.
Which solar panel brand should you buy?
Brand choice comes down to efficiency, warranty length, and price tier, and the major manufacturers split cleanly along those lines:
| Brand name | About company | Key details |
|---|---|---|
| Maxeon | Singapore-based solar panel manufacturer known for ultra-high-efficiency solar cells. | Gen 6 IBC technology, up to 22.8% efficiency, 25- to 40-year warranty, sleek design |
| REC Solar | European manufacturer focused on high-performance and durable panels. | HJT technology, low carbon footprint, strong in Europe and the U.S. |
| Qcells | South Korea-based brand known for reliable and affordable panels. | Competitive pricing, solid performance, high availability |
| JinkoSolar | One of the world’s largest solar panel manufacturers by volume. | Mass production, global reach, solid performance, cost-effective |
| Canadian Solar | Global solar manufacturer with operations in Canada and China. | Diverse product line, bifacial options, cost-efficient |
| Trina Solar | Chinese brand known for innovation and high-output panels. | Vertex series, bifacial tech, strong utility focus |
| LONGi Solar | Leading monocrystalline manufacturer based in China. | PERC and bifacial leaders, efficient and cost-competitive |
| Tesla (Solar Roof) | U.S. company offering integrated solar shingles and standard panels. | Integrated solar roof, Powerwall combo, direct-to-consumer |
| Panasonic Solar | Japanese electronics giant with high-efficiency solar panels. | HIT and HJT technology, excellent temperature performance |
Check both warranties before you sign
Every panel carries two separate warranties, and the difference decides who pays when output drops:
A performance warranty guarantees the panel produces above a stated baseline across its lifespan. When production falls below that line for a sustained period, the manufacturer repairs or replaces the panels.
A product warranty, sometimes listed as an equipment or material warranty, covers panel failure from defects, corrosion, bad wiring, and premature wear. These run 10 to 12 years and pay for replacing faulty panels.
How to vet installers and clear local approvals
The installer decides how well your system performs, so vet credentials before price. Our full guide to choosing a solar installer covers the process step by step; these are the four checks that matter most:
- Credentials: Hire an installer with current North American Board of Certified Energy Practitioners (NABCEP) certification, and only licensed electricians who are bonded and insured.
- Company type: Local installers know your region's climate and codes but may charge more. National installers price aggressively but schedule less flexibly and may lack local experience.
- Customer reviews: Compare the output customers report against the output the company promises.
- Post-install support: A good installer provides monitoring tools, repair timelines, and warranty servicing after activation.
Bring the right questions to ask solar companies to every sales call, and clear these items with your city, utility, and HOA before signing:
- Building permits: Confirm which permits your municipality requires and whether the process includes a structural inspection.
- Utility approval: Sign an interconnection agreement with your utility to run your system in parallel with the grid, and apply for net metering.
- HOA and zoning rules: Check bylaws for restrictions on panel visibility or roof modifications before the design is final.
- Fire code and setbacks: Leave access lanes between panels so fire services can reach the roof.
How long does buying and installing take?
The full process runs two to six months from choosing a provider to switching the system on. After you sign, the project moves through site assessment, system design, permitting, installation, inspection, and utility approval. The physical install finishes in a few days; permits and approvals consume the weeks.
Is solar worth it long term?
For most owners who stay put, yes: the system repays its cost in about 10 years and keeps producing for 15 to 20 more. Four long-term returns stack on top of the bill savings:
- Carbon offset: The average system prevents three to four tons of CO₂ emissions per year.
- Home value: Homes with owned solar systems sell faster and at higher prices.
- Energy independence: Your own production shields you from utility rate changes and grid instability.
- Disaster resilience: Panels paired with batteries supply self-contained backup power during outages.
Bottom line: buying solar panels for home energy
Buy solar in this order: confirm your roof and homeownership time expectations justify it, pick the panel type that fits your space, size the array from your kWh use and sun hours, then compare brands and installers on warranties and verified reviews. Skip or postpone the purchase when your roof needs replacement, shading kills production, or you plan to move before the 10 year payback lands. Get itemized quotes from at least three installers, because the spread between bids often exceeds the price of the panels themselves.
