Forecasters expect home solar to take a big leap in 2025. So if you think this is your year to go solar, you’re not alone!
Maybe you’ve talked to friends and neighbors about their solar equipment, done some initial research, and understand the benefits of going solar. Now you want to dig deeper and learn more.
This guide gives you what you need to know as you prepare to install solar panels for your home.
Solar Panel Weight on Roof
Let’s start with a common concern among those new to home solar. Does my roof have the structural integrity to handle solar panels? At only two to four pounds per square foot, solar panels fall well below the weight tolerance of most roofs, which is typically at least 20 pounds* per square foot. So, chances are your roof is more than capable.
Roof Age and Design
Don’t worry about weight but do worry about age. Solar panels have at least a 25-year life span, and you want your roof to last as long. If your roof is near replacement age, seek out a solar company that offers solar installation with roof repair or replacement. Combining these projects can save some homeowners thousands of dollars, according to the U.S. Department of Energy.
Even if your roof is new, it could still face challenges when it comes to solar equipment. Maybe it has unusual contouring or is heavily shaded. Things like the right direction and angle can also impact how much sunlight it gets. Talk to an expert to get a better idea if solar is suitable for your roof.
What is Solar Offset and How Does it Affect my Bill?
How much energy do you want to get from your solar equipment rather than your electric utility? If you say as much as possible, you’re in good company. Most people want their “solar offset” to be as high as possible. It’s an important number because it affects how much savings you can achieve by going solar.
To better understand solar offset, look at your utility bill. You’ll see it’s broken down into various charges. Pay close attention to the supply charge, which shows how many kilowatt-hours (kWh) of electricity your home uses. Your solar system reduces or “offsets” this part of your bill.
Your kWh usage will vary from month to month, so your home solar installer will analyze your electricity bills to calculate an annual average. Based on the size of your solar system, they can determine how much of that energy you can offset by generating your own electricity instead of buying it from your utility. That’s your solar offset.
Homeowners can typically reduce 80% of their utility supply charge with solar. But your solar offset may be more or less depending on other factors, such as seasonality and changes in your energy consumption.
Learn about the impact of seasonality on your solar output
Solar Panel Output
Your solar offset and other factors — such as rooftop contour and solar panel output — go into calculating your solar system size.
Before deciding the size and configuration of your solar array, your installer will gauge your roof’s “peak sunlight,” which refers to the period when the sun's intensity on a roof averages 1,000 watts of power per square meter for one hour.
Sunbelt states average as many as eight peak sun hours daily, while northern climes may achieve only 2.5 to 3.5 hours daily. Your panels will be angled to maximize your roof’s peak sunlight capabilities.
Solar Panel Efficiency
In determining your solar system size, your installer will also consider solar panel efficiency and wattage. Wattage measures the amount of sunlight the panels can convert into energy under ideal conditions — typically 250-400 watts for most residential solar panels.
Higher-wattage panels usually take up more space than lower-wattage units. But that doesn’t mean bigger panels are necessarily better. Sometimes smaller panels better fit the contours of your roof, allowing for greater capture of sunlight. The goal isn’t so much about getting the most energy from each panel as it is getting the most energy from your roof space.
Solar panel efficiency refers to the amount of electricity that your solar modules actually convert to electricity. It’s common for solar panels to achieve 20% efficiency, meaning 20% of the sunlight shining on the panels becomes electricity. Efficiency can be affected by various factors, such as:
- The quality of materials used in the panels
- The angle and orientation of your roof (south-facing is ideal but not always possible)
- The influence of tree shading and the climate where you live
How to Monitor Solar Panel Output
Over time, normal wear and tear causes solar panel efficiency to wane, a phenomenon known as solar degradation, which slowly reduces performance. Fortunately, most manufacturers take this into account and guarantee at least 80% of their products' original output by year 25. If the panels fall below the threshold, the manufacturer offers replacement panels.
Top solar service providers like Sunnova offer monitoring, maintenance and repairs. Some also offer production guarantees, meaning if your system doesn’t generate the amount of energy outlined in your contract, you may be credited. Make sure when deciding on a solar installer, you choose a company that provides after-sale service to keep your system performing optimally over time.
Learn more about our production guarantee
Can I Add Solar Panels to my Existing System?
Given that families expand and household needs grow, your electricity use just might increase. In addition, environmentally conscious consumers are increasingly electrifying their homes, swapping out gas stoves with electric induction ovens and oil and gas heating systems with electric heat pumps.
Add to that the rise in electric vehicle (EV) purchases — which are projected to account for between 13% and 29% of new cars purchased in the U.S. through 2050* — and you see why it’s a good idea to ask your solar installer to size your solar system to be “future-ready.”
While it’s better to buy a larger solar system in anticipation of future energy needs, some customers may choose to add a second system instead.
Grid Tied vs. Off Grid Solar Systems: Equipment Configurations
Most home solar systems in the U.S. are “grid-tied,” meaning your home remains connected to your local utility. This setup allows you to capture the benefits of net metering. However, in recent years, some states and utilities have weakened net-metering benefits. In rare cases, it may make economic sense to go off-grid, but it’s a big decision since you would no longer have utility power as a backup.
Off-grid residential solar is generally only cost-effective in areas with high electricity rates, remote locations where connecting to the grid is prohibitively expensive, or regions with unreliable grid infrastructure.
Off Grid Benefits with Solar + Battery Storage
If you truly want to go off grid, a battery (often multiple) is necessary to supply power when the sun isn’t shining. But even if you’re connected to the grid, there are plenty of reasons to add a battery, whether you’d like protection from outages or want to use your stored solar energy to power your home after sunset or when utility rates are highest. The solar battery combination has become popular, expected to account for 81% of new electricity capacity added to the U.S. power grid in 2024.
A battery can supply several hours of backup power when the grid is down*. Batteries also open the door to achieving greater savings on your electric bill through sophisticated energy management.
Some utilities offer rates that change throughout the day, week or year. And if your utility enforces time-based rates, you may see higher prices during peak evening hours when demand is high (called on-peak rates). Batteries can be particularly valuable in this case.
If you have a battery, you can store the excess solar energy your panels produce during the day and use it later to avoid buying grid electricity when prices are high. This not only helps protect you from peak rates, but also allows you to maximize the amount of solar energy you use, especially in areas where net-metering benefits are limited or unavailable.
While the price of home solar batteries has fallen considerably in recent years, they still add a notable cost to your solar investment. If cost savings is your primary goal, it’s important to work with your solar installer to calculate the time it will take to reach your economic breakeven based on your unique needs.
You might also consider adding a load controller to prioritize only essential loads during an outage—extending your battery’s runtime and potentially reducing the number of batteries you need to purchase.* A reputable solar company like Sunnova can help you determine if adding a battery with or without load control makes economic sense for you.
Is a solar battery worth it? Find out
Do I Need a Smart Electric Panel or Load Controller with My Solar?
Want to make your home smarter? Smart electric panels are increasingly being paired with home solar systems because they allow you to monitor and control where and when electricity flows in the home using a mobile app.
In the event of a power outage — or if electricity prices are high — you can program your solar and battery system to prioritize certain appliances first, perhaps medical equipment, your refrigerator, or air conditioning and heating. A smart panel also allows you to remotely control appliances through your phone while you’re away from home. So if you accidentally left your electric oven on, no worries!
While a smart electric panel responds to your immediate energy needs, a load controller integrates with your electrical panel to manage your power consumption more precisely. It lets you cap the power used by turning specific loads on and off. This can regulate the amount of power a specific circuit consumes — allowing you to save money during peak demand hours and turn off non-essential appliances during an outage to extend the life of your solar battery.
Learn more about load control
Can I Charge an EV with Solar Panels?
If you’re in the market for an electric vehicle, this is an excellent time to install a home EV charger. Or perhaps you already have an EV charger, but it’s not very fast. If you upgrade to what’s known as a Level 2 charger, you’ll see a marked difference in charging times. Level 2 chargers can get your EV ready to go six to eight times faster than their Level 1 counterparts.
What about charging your EV from home solar? If you’ve already committed to sustainable transportation, why not maintain your pledge to clean energy and recharge it from the sun? By sizing your home solar system to account for EV charging, you can run your vehicle on sunshine without worrying about gas prices or a sharp increase in your electricity bill.
Find out how many solar panels it takes to charge an EV
Can I Package These Extras Together with My Home Solar?
Check with your solar installer about packages that offer batteries, EV chargers, and load control or smart electrical panels with solar installation. A “one-stop-shop” option might prove less expensive than buying and installing the systems a la carte, not to mention the convenience of having all of these systems integrated at one time by a solar expert.
How Much Do Solar Panels Cost?
It’s little surprise that solar installations are rising, given that costs have fallen 40% in the last decade. But it’s not just the price tag that makes solar attractive; it’s also consumer-friendly financing packages and ample state and federal tax incentives. Two common and economically attractive ways to finance your home solar system are:
- Third party-owned lease or power purchase agreement (PPA).
- Equipment purchases via a loan or cash.
The two approaches offer different benefits. The one you choose will depend on your household’s budgeting circumstances.
Solar Leases and PPAs
Power Purchase Agreements (PPA) and solar leases offer several key advantages that make them popular choices. You don’t have to make a large upfront investment or take out a high-interest rate loan. You also won’t need to worry about adding additional insurance coverage — the solar company handles insurance for the system, protecting it against theft or damage.*In both cases, a third party owns and operates your home solar system.
With a PPA you pay only for the energy the system produces, generally at a predetermined kWh rate under a long-term contract. A solar installer will strive for a monthly payment that beats the utility rate. The homeowner receives a predictable energy rate and is spared having to think about solar maintenance and performance.
One caveat: A third party owned option may not be right for you if you are eligible to claim the full solar tax credit or other government incentives available for home solar systems. Under a lease or PPA, the solar company that owns the system receives the tax credit. You benefit indirectly because the incentives allow the solar company to minimize customer costs (plus, not every homeowner has the tax appetite to take full advantage of the credit).
Leases operate in a somewhat similar fashion, but the payments are calculated differently. You pay a flat, predetermined amount of money each month with a solar lease, much like an auto lease. In contrast, a PPA payment is based on a kWh charge. In both cases, the contracts generally run 20-25 years.
Solar Loans or Cash Purchases
Meanwhile, purchasing solar panels for your home is akin to buying a car. You pay for your system and installation upfront, either with cash or by taking out a loan and paying over time with interest. This approach has two advantages:
- Your system typically costs less in the long run if you own it rather than sign a PPA or lease.
- Any government incentives or tax credits accrue directly to you (granted you are eligible).
- Selling your home may be easier since you can pay off the loan and potentially include some of that cost into your selling price if the homebuyer doesn’t like the idea of paying a monthly bill to the solar provider. However, some solar companies also offer a lease buyout after a certain number of years so be sure to read the fine print on your contract before signing.
If you buy your solar equipment, you’ve either tied up cash you could invest or use elsewhere, or added loan interest rates to the overall cost of putting solar panels on your home. An expert solar company will take the time to walk you through the options.
There is a lot to think about when you go solar. Joining the home solar revolution is made easy by working with an expert solar installation professional. Sunnova is here to help.
Make the sun work for you
