Before you start: Gather 12 months of bills and check your roof’s condition and sun exposure first.

Is your home a good fit for solar panels?

A sound plan starts with an honest look at your property. According to the U.S. Department of Energy’s homeowner guide, solar panels are built to work in all climates, but certain rooftop conditions can make an installation less practical. The age of your roof, nearby tree cover that creates excessive shade, and the size, shape, and slope of the roof all matter. The guide notes that panels typically perform best on south-facing roofs with a slope between 15 and 40 degrees, though other roofs may still be suitable. You should also consider how long it will be before your roof needs replacement, since the guide lists the roof’s remaining life as a factor. If a solar professional determines your roof is not a good candidate, or if you do not own your home, the Department of Energy points out that community solar programs let multiple people share a single array and divide the costs. A detailed property assessment helps you decide before you spend money on a design. For more help evaluating your home, read our guide to roof suitability.

Review your household electricity use

Before choosing equipment, understand how much electricity you actually use. Gather at least 12 months of utility bills so you can see seasonal patterns, because heating and cooling loads can swing sharply. The Virginia Cooperative Extension offers a straightforward formula for estimating an appliance’s annual consumption: multiply its wattage by the hours used per day, divide by 1,000 to get daily kilowatt-hours, then multiply by the number of days it runs each year. The same source provides a table of typical wattage ranges for common appliances, from refrigerators and clothes dryers to computers, and notes that many devices draw a small phantom load even when switched off. Unplugging them or using a power strip eliminates that hidden draw. The U.S. Department of Energy also recommends pursuing energy efficiency upgrades first, because when you run Energy Star appliances and other efficient products, you need less solar energy to power your home. A careful energy audit gives you the baseline numbers required for accurate system sizing. Explore our full breakdown of household energy use for step-by-step calculation methods.

Estimate solar production for your address

Once you know your usage, you need a realistic picture of how much electricity panels on your roof can generate. The National Laboratory of the Rockies operates a tool called PVWatts that estimates the energy production of a grid-connected photovoltaic system for any address in the world. You enter your location, system size, array type, tilt, and azimuth, and the calculator returns monthly and annual production estimates using local solar radiation data. The tool’s website cautions that its predictions include many inherent assumptions and uncertainties and do not reflect variations between PV technologies or site-specific characteristics beyond the inputs you provide. The expected range is based on 30 years of actual weather data at a given location and is intended to show the variation you might see year to year. This is a starting point; the Department of Energy advises working with a solar installer for a custom estimate of how much power your system is likely to generate. If you want to compare panel types later, see our section on residential solar panels.

Size the system to match your goals

Correct sizing is key to getting a system that is both effective and useful, according to the Pennsylvania Public Utility Commission’s solar electricity basics factsheet. It recommends using PVWatts to estimate a system size based on your annual electric usage and design preferences. The process is straightforward: enter your location and total yearly kilowatt-hour consumption, and the tool suggests a DC system size in kilowatts. The U.S. Department of Energy’s guide notes that the National Renewable Energy Laboratory (the lab behind PVWatts) uses an average system size of 7.15 kilowatts direct-current for its analyses, but your size should be based on your own bills and available roof space. If your roof cannot fit the size you want, efficiency measures or higher-wattage panels can help close the gap. Detailed sizing steps are covered in our article on home system sizing.

Plan mounting, orientation, and basic system design

The U.S. Department of Energy’s solar design basics article explains that a PV array must be mounted on a stable, durable structure that can withstand decades of wind, rain, hail, and corrosion. To obtain the highest annual energy output in the northern hemisphere, modules are pointed due south and inclined at an angle equal to the local latitude. Rack mounting is described as the most common method because it is robust, versatile, and easy to construct and install. The article also introduces inverters, which convert the direct current (DC) produced by panels into the alternating current (AC) that homes and appliances use. Systems may use a single central inverter, or microinverters attached to each module, which can be helpful when partial shading is a concern. The Department of Energy adds that inverters are expected to need replacement at least once during the 25-year life of a PV array. You can learn more about these components in our guide to home inverters and installation planning.

Understand net metering and utility interconnection rules

How your utility credits you for excess energy changes the financial picture. The U.S. Department of Energy defines net metering as an arrangement in which system owners are compensated for solar power exported to the grid. It explains that the name comes from the 1990s, when the meter simply ran backwards, but the situation is rarely that simple today. Whether your system qualifies for net metering payments, and at what rate, depends on policies and practices in your state and with your electric utility. The guide recommends contacting your local utility directly to ask about availability, eligible system sizes, customer types, and how bill credits are designed. This inquiry should happen early in your planning, because the connection rules can affect system size, whether batteries make sense, and the overall payback period. If you are considering batteries for backup or time-of-use savings, browse our battery backup and home battery storage sections.

Choose a certified professional and review contracts carefully

The U.S. Department of Energy states that the best way to install solar is through a qualified professional who holds the industry-standard certification from the North American Board of Certified Energy Practitioners (NABCEP). It suggests reading company reviews thoroughly, comparing multiple quotes, and reviewing detailed contract terms before signing anything. The Department of Energy also highlights that solar co-ops and Solarize campaigns let groups of homeowners collectively negotiate rates and select an installer, which can lower costs through group purchasing. Whether you buy the system outright, finance with a loan, or use a lease or power purchase agreement, the financial structure affects long-term savings and who claims any available tax benefits. Because incentives change, check current official sources rather than relying on a single sales pitch. For help comparing quotes, see system comparisons and financing considerations.

Stay clear of common solar scams

The Federal Trade Commission warns that scams often begin with an unexpected phone call, message, or in-person visit from someone falsely claiming to represent the government or your utility. The FTC consumer alert states explicitly that “free” or “no cost” solar panel offers are scams, and that the federal government does not install solar systems in homes for free. Scammers may dangle promises of huge rebates, tax credits, or utility incentives that do not exist, and they often use high-pressure tactics. The FTC advises taking your time, because legitimate businesses and government agencies do not pressure you to act immediately or demand up-front payment through cash, gift cards, wire transfers, payment apps, or cryptocurrency. Protect your personal information, and do not respond to unsolicited requests for your name or address just to “see if you qualify.” If you believe a company has misrepresented itself, the Department of Energy directs consumers to report it at ReportFraud.FTC.gov or to contact the Consumer Financial Protection Bureau. Nonprofit legal services and state consumer protection offices can also assist if you have lost money to fraud. Understanding your contract and financing path is part of this defense; explore ownership and warranties before you sign.

Home solar planning checklist

Step What to check Key action
1. Roof suitability Age, tree cover, size, shape, slope, south-facing exposure Have a professional assess your roof; consider community solar if your roof is not suitable
2. Electricity usage 12 months of bills; major appliance loads and phantom draws Calculate your annual kWh; pursue efficiency upgrades first
3. Production estimate Location, array type, tilt, azimuth Run a PVWatts estimate, then get a custom installer assessment
4. System sizing Annual kWh use vs. available roof space Use PVWatts to find a DC system size that matches your consumption
5. Mounting and orientation South-facing, tilt equal to latitude, rack vs. tracking Select the mounting approach and inverter type with your installer
6. Utility rules Net metering availability, credit rates, interconnection requirements Call your electric utility and understand the policy before you commit
7. Installer selection NABCEP certification, reviews, multiple quotes, contract terms Compare bids and read contracts before signing
8. Scam prevention “Free” offers, pressure tactics, payment demands Verify claims independently and report suspicious behavior to the FTC

Frequently asked questions

Do I need a battery if I stay connected to the grid?

The U.S. Department of Energy explains that storage lets you save solar energy and use it later, such as when you run appliances at night or during a power outage. Whether a battery pays off depends partly on how your utility credits exported power, so ask about those rules first. If you want backup power when the grid goes down, ask your installer whether battery storage options are available for your system design. Our resources on battery capacity planning can help you weigh the decision.

How accurate are online solar calculators?

The PVWatts calculator run by the National Laboratory of the Rockies provides an estimate based on 30 years of historical weather data and the system inputs you supply. Its own documentation cautions that the predictions include many inherent assumptions and do not reflect differences between specific solar modules, local shading conditions, or installation details beyond the inputs. Use the tool for early planning, but treat its numbers as a range, not a precise value, and ask a certified professional for a custom assessment that incorporates a site visit.

Is my state one where HOAs can block solar panels?

The U.S. Department of Energy notes that many states and territories have enacted solar access laws that prevent homeowners’ associations from prohibiting or unreasonably restricting solar installations. These laws vary by state, so if you have an HOA, check the rules that apply in your area. In most cases, you can install panels, though you will likely need to submit a request and follow the association’s architectural review process.

When you are ready to dig deeper into the financial side of your project, visit our main guide to home solar planning and the companion resource on home solar costs and decisions.

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