Solar panels have been around for a long time, and in many areas, you can see them all over the place. They’re powering street lights and emergency signs, and increasingly they’re showing up on your neighbors’ roofs. Solar energy offers a lot of benefits to your home, reducing energy bills (even earning you money if you sell your excess production back to the grid) and providing robust emergency power when combined with a good home battery.
So it’s no surprise that more and more people are seriously considering installing solar panels on their homes. If that’s you, you’ve probably discovered that this isn’t a small project, and figuring out the best way to get started can be a challenge. If you’re just starting your solar energy journey, here are some of the basics you need to know before getting started.
Traditional panels versus solar shingles
First, you’ll need to figure out what type of solar panels you’ll be installing. There are two basic categories here: Traditional panels, and solar shingles. Panels are what you probably think of when you think of solar energy—square, flat glass panels that sit flush to your roof, soaking up the sun. Solar shingles are a relatively new product in the sector that mimic the traditional size and look of roof shingles. Currently, solar shingles aren’t as efficient as solar panels and are a lot more expensive, but they’re much more aesthetically pleasing. On the other hand, you can remove solar panels and take them with you if you move, but you can’t do that with solar shingles.
The next thing to consider is efficiency, which is a measure of how good they are at converting sunlight into electricity. Different solar panels and shingles will offer different efficiency rates, with the higher ratings being more expensive. If you have a lot of roof that gets a lot of sun, you can go with a lower efficiency rating to get the energy output you need, but if you have a smaller roof, you’ll need to splash out for the more expensive panels.
Most solar products will offer efficiency ratings between 10% and 20%. Most solar shingles come in at the lower end of that scale, though some of the pricier ones using silicon offer up to 20% efficiency. Generally speaking, you should go for the highest efficiency you can find (and afford). All solar products lose efficiency over time, but you should look for solar panels that retain 80% to 90% of their efficiency for a period of 25 years.
How many you’ll need
How many panels or shingles you’ll need depends on the efficiency rating, the amount of sun you can expect, and how much power you need to generate. The average home in the U.S. uses about 893 kilowatthours (kWh) of electricity every month, so we’ll use that as a representative goal (obviously your usage might be lower or higher).
Every solar panel or shingle will have a power output rating in watts, and most of the newer panels will produce between 275 and 400 watts of power, and solar shingles can offer up to 70 watts each. You can calculate how many kWh you get by taking the number of hours of sunlight your roof gets, multiplying it by the output rating of your panel, and then dividing by 1,000.
For example, if your panel has a 300 watt output and will get about five hours of direct sunlight every day: 5 X 300 = 1,500/1000 = 1.5 kWh. So if you’re getting 1.5 kWh every day from your panel, that’s about 45 kWh a month. If you need 893 kWh every month for your home, you’ll need about 20 panels or about 80-100 shingles to get there—though of course, fewer panels or shingles will still reduce your electric bill.
Installing solar panels can be a DIY job if you’re skilled and know your way around your roof, though you’d be well advised to leave the wiring to an electrician. But most people will need to pay to have the panels installed. Costs vary widely between regions, but the range is about $3 to $5 per watt, or $14,000 to $25,000 before any tax incentives. Aside from the number and efficiency rating of the panels you choose, the type of roof you have will be a factor—the more complex your roof line, the more expensive this will be.
The state of your roof
Finally, your existing roof will factor into your costs. Solar panels are designed to be installed on top of your existing roof, so your roof has to be in good shape. The rule of thumb is that your roof should have a minimum of 10 years left in it to make installing solar panels worthwhile—because when the time comes to replace your roof, those panels will need to be removed and then re-installed. Solar shingles are designed to replace your current roofing material entirely, so they are best considered only if you’re going to be replacing your roof anyway.
If that $14K-$25K price tag terrifies you, keep in mind that there are some really big tax incentives offered to encourage people to install solar systems. The Federal Solar Investment Tax Credit offers a 30% reduction in the cost of installing solar panels, so a $20,000 installation magically becomes a $14,000 installation. This credit can be claimed as long as your system was installed between January 1st, 2006 and December 31st, 2023, is located at your primary or secondary residence in the U.S., and the system is new and original to the home.
There may also be local tax incentives or rebates and utility rebates in your area. If you’re planning to install a solar system, it’s well worth your time to look into any and all local incentives that may help defray the overall cost.
Where to buy
Finally, you need to buy and install your solar panels or shingles. The simplest option might be a “big box” store like Home Depot and Lowes. Both will gladly sell you everything you need, and can even handle pairing you with a contractor. Costco has also partnered with a company called Sunrun to make installing solar systems fairly easy and affordable. And Tesla will sell you their solar panels, install them, and even pair them with a house battery—but Tesla tends to be a lot more expensive than other options.
You also might not get the best quotes if you go for the convenience of a Home Depot-type store. There are many solar-specific companies out there that might offer more expertise and a wider range of options, not to mention potentially a better price. Most are not present in every U.S. State, so you’ll need to check which options you have in your area.