Should you invest in solar power? There are a few things to consider such as “how long do solar panels last,” as well as costs and savings. While many consider the upfront costs, new solar panels are far less of an investment in comparison to previous solar panel systems. In addition, you can save hundreds on your energy bills each year, and there are some tax deductions for certain solar panels.
So, how long do solar panels last?
Solar panels last for an estimated 25 years according to most warranties, but if maintained, they can last for many years longer. One study by NREL found that most solar panels continue to produce power after the 25-year mark. However, the output may be reduced.
Best of all, the long-term value of solar panels is much higher now. As more people look to invest in sustainable energy, homes and commercial spaces can benefit from choosing solar power instead of conventional power. You may even be able to get rebates to make it even more beneficial.
There are many variations of solar power currently. There are also solar power self storage systems which use a back-up battery source, such as a lithium-ion battery. These can be used to help you stay powered throughout your home even on cloudy days.
Here is an example of a lithium-ion solar power wall from Tesla:
Thinking of getting solar panels? These are some other factors to consider.
How to Test Solar Panels
Have you already decided to go solar and now you need to test your panels? Most solar power systems are extremely reliable and covered by a warranty, but you can test their functionality with these methods.
Need a visual to help with testing your panel? This guide shows you everything you need to test out your panels:
Check Your Local Weather
Solar panels do work on days with cloud and rain, but the output is not as much as it is on bright das with a lot of sunshine. Most solar systems decrease in power, and they operate only at 10 to 25 percent of their total rated capacity.
You should make sure that your solar panels are getting the most possible access to the sun. This may mean trimming trees to open up a wider area for the sun to shine through.
Test Your Inverter
The inverter is the central brain of our solar power system. If it’s not working properly, then your output will drop. The efficiency rating of your solar power system depends on whether your panels are connected to direct DC optimizers. Does the screen stay on or off? You may be able to check indicator lights for more issues. If blinking red or orange, it could mean that your inverter is having trouble.
Inspect Your Solar Meter
The solar meter monitors your output and makes sure that your screens share this information. You should look at how much power each panel is generating. If you notice that kilowatt/hr is increasing, then you aren’t experiencing any troubles with your output.
Use a Voltmeter
Using a multimeter such as a voltmeter is the best way to test a 12V panel. You’ll first need to set the meter according to your specific DC area, which can be found in your solar panel manual. You’ll need to pick a volt range that is capable of showing the most voltage while the meter is in an open circuit or when it isn’t connected to a battery charger.
If you need to see a visual guide, here is an expert step-by-step tutorial on using a voltmeter with a solar panel:
Typically you’ll use a range of 3 digits, such as 100 V or 200 V. You should never choose 20 Volts or less because it may not display the panel output correctly. Once you have set the meter, you’ll need to connect the black wire to the port labeled COM. The red wire or positive probe connects to the port usually labeled V or mA.
Once connected, you should see the voltage displayed on the screen of your multimer. You want to see a range between 15V and 23V for most solar panels.
How to Fix Solar Lights
Solar lights come with a lot of benefits. In fact, they can be pretty simple to install with some of the latest styles. However, they also have a few quirks that make it difficult to understand when they have completely stopped working or whether something has blocked the solar light from gathering power.
Here are a few things to do if you want to fix your solar lightfast:
Check for Blockage
In most cases, solar lights stop working when a plant is in the way. Since solar lights have to charge up through the sun, they cannot properly work if they do not have access. Shady trees, a neighbor’s new palm, or even frozen soil on a solar panel can cause blockage. You will need to cut down trees, reposition the lights, or clean the solar light to restore your power source.
Inspect the Light’s Condition
Solar lights have a switch that turns on the panel. This switch can be found typically on the bottom of the light or underneath the cap. If you do have a cap light, you’ll need to turn it counterclockwise to remove the top and access the switch. If you are sure that the switch is set to on, then you may need to reposition the light so that it has access to the sun’s rays for over five hours.
Are Lights Rusting Out?
Sometimes moisture builds up inside of the light, and it can corrode the connections between the light and panel. When checking your solar light, you may also want to look for badly corroded connections, debris, and rust.
You may also want to check that the wires connecting your solar panels are also in good shape with no breaks or cracks. Animals and debris often wear down the integrity of these wires. You may need electrical tape to repair these wires, or it could require a replacement.
Cloudy Glass on Solar Panels
In other cases, solar panels simply cannot access the sun like before because the glass is dirty and clouded. If you can’t see through the plastic casing, then it’s likely the solar panel isn’t working properly. You’ll need a damp cloth, such as a microfiber towel, to clean the panel. Once dried, you can use clear nail polish to apply a protective coat to the solar panel. You should allow the nail polish to dry before setting the solar light back in place. This ensures that the panel can receive light again.
Is It the Battery?
If you have checked everything above and your solar light still isn’t working, then it may be time to change the batteries. To check, you will need to look under the solar panel’s battery compartment. You’ll likely need a screwdriver to open up the panel and check that the batteries are in good condition with no warping or corrosion.
Solar batteries come in different shapes and sizes, so it depends on your make and model as to what battery type you’ll need. Most US households use about 30 kilowatt-hours of energy every day. Most solar batteries delivery at 10 kWh at max capacity. So if you have three solar panels, then it’s likely you can run your home on three solar batteries for a few hours if it’s not getting enough power from the sun.
There are three battery types with most solar panel systems including:
- Lead acid
- Lithium ion
Of the three, lithium-ion batteries are the most durable and long-lasting, but they also don’t come cheap. You’ll need to talk with your solar panel manufacturer to determine the battery type and replacement instruments.
- Active Time: 3-5 hours
- Lumen: 1,000; Color Temperature: Super Bright
How Long Do Solar Batteries Last
If you are pairing a battery with a typical solar PV system array, then one or two batteries can provide you with enough power to turn on the lights during the night. However, without recharging the panel, one solar battery will not keep the lights on for more than 24 hours.
There is another way to answer this question as to the total lifespan of a solar battery. Most solar batteries have between 5 and 15 years depending on the type.
Their lifespan is also affected by extreme temperatures. If your solar panels are constantly freezing or overheating, then your battery may need to be replaced more often. This is because when a PV battery decreases in temperature below 30 degrees Fahrenheit, it will require more voltage to recharge at the maximum rate. This causes the battery to work overtime. When a battery increases in temperature to over 90 degrees Fahrenheit, then the battery may overheat and need to reduce its charge.
Tesla provides a temperature moderation feature to prevent freezing and overheating. If your solar system doesn’t have this feature, then you may want to consider an enclosure during extreme temperatures.
In terms of battery types, here is how each one stacks up in terms of durability and replacement time frames.
- Lead-acid batteries: These are the lowest cost, but they also have the lowest solar battery lifespan. These batteries are the best options when you must install several panels and want to cut down on costs.
- Lithium-ion batteries: Most new home energy systems rely on durable, long-lasting lithium-ion batteries. While these are the most expensive, they are also the most reliable and durable. They also have the longest solar battery lifespan in comparison to lead-acid and saltwater batteries.
- Saltwater batteries: Some newer solar systems use saltwater batteries because they don’t contain heavy metals and rely on electrolytes instead. This makes them slightly more affordable than lithium-ion batteries, but they also have not been tested fully to see how long they will last.
If you want the longest battery life, lithium ion solar batteries seem to be the best out of the different types available. However, this could change as more technology like saltwater batteries develops in the future.
How Long Does It Takes for Solar Panels to Pay for Themselves
There are a lot of financial benefits to installing solar panels and relying on solar energy instead of traditional power. However, it does come with a large upfront investment. Still, homeowners who invest in solar receive a high rate of return, and you can claim tax credits for installing solar systems in some states.
To understand how long it will take for your solar system to pay you back, there are a few things to consider first.
What is a Solar Panel Payback Period?
You can calculate your “breakeven” date with the solar panel payback period. This number is the moment that you earn back what you spent on your investment through energy bill savings and tax deductions. The length of time also changes depending on the initial investment costs.
For example, let’s say you purchased a solar panel system for $20,000 to cover 600 square feet on your roof. If you live in Florida, you’ll receive a rebate of up to $8,000 for a new solar panel system. As long as you live in a sunny area that receives a generous amount of sun, you can typically earn back your investment in less than 7 years.
How Do You Calculate Your Solar Panel Payback Period?
There are several factors including:
- Gross cost of solar panel system: This is the total investment for purchasing and installing the system.
- Tax incentives: There are a few tax deductions and rebates that can save you about 30% of the total cost of your system. Depending on your state, you may have other rebates and incentives available. You can check to see your state’s solar power incentives here.
- Average monthly electrical use: Do you use a lot of power in your home? You may require a bigger system if so. You can offset energy costs by using solar power each month. If you have higher energy costs, solar panels can quickly reduce these bills to little or nothing each month.
- Estimated electricity generated: Most solar panels generate 10 kWh, and the average households need 30 kWh per day. The size of your roof, weather conditions, and any blockages can change the amount of electricity generated.
Once you determine the combined costs of investment and installation, then you can add up your credits and annual benefits. If you were spending $150 each month on electricity, then your solar panels will likely reduce your bill to $0. This means you saved $1,800 a year.
- Working Time: 8-10 hours
- Battery Type: 2200mAh rechargeable battery
How Much Do Solar Panels Save
Depending on the type of solar power system you select, you could save a lot of money each month. However, most people who switch to solar power do not see an investment return for up to 8 years or more. Still, there are savings each month due to lower energy bills.
Use Google’s Project Sunroof to Understand Savings
Google started Project Sunroof to show people how much they can save with solar panels. This calculator bases savings on your address and usable sunlight in the area, as well as the amount of roof space.
Solar panel savings depend on where you live for the most part. For example, estimated savings for a home in Fresno, California with lots of access to the sun is up to 96 percent on their energy bills. In some areas, you may be able to completely eliminate your power bill altogether.
Replacement Solar Batteries
Most solar power systems do not come with “storage-ready” systems that include batteries, but if yours does, then you have a great backup power source. Typically, your system uses a lithium ion battery in larger solar panel system setups, and the replacement instructions depend on the manufacturer.
Before replacing your batteries, you should check whether the battery is truly dead or not. Solar batteries cannot charge properly if they are in the shade, so before you replace them, you should consider if the solar panels are in the best position to charge. If you are not sure if the batteries are charging, you can always move the panels to direct sunlight for a few hours to see if the battery starts working again.
If you still believe that the battery is dead, then you can replace them easily. You’ll need to switch the panels off before you remove the cover and “unplug” the battery, however. You should consult the specific instructions with your system to ensure that you get the right battery type.
There are typically three lithium-ion batteries that are used in “solar panel plus storage systems.” These include pouches, cylindrical 12V lithium batteries, and prismatic lithium-ion batteries.
Most solar panel systems use prismatic lithium-ion batteries, which have corrugated sides and padded cells with air gaps. These help to cool down the battery, so it’s important that you study how the battery is placed before replacing the unit.
Wrapping Up: Is Solar the Long-Term Power Solution?
Do you know anyone with solar panels that have lasted longer than 10 or 20 years? What’s your experience with solar energy? Let us know your thoughts in the comments.
Also, please share if you think this article can help someone contemplating solar power for their home or office.
Solar power systems typically last over 25 years. While many are only rated for 25 years, this is just the minimum. Many systems last for decades longer, but there can be issues with different panels and their components, such as with solar storage that uses batteries. Lithium-ion batteries offer the most long-term solution, but their cost can deter those who simply want to rely on free power from solar panels.
When looking at a solar system for your home or office, you should consider the amount of power you currently use and the roof space that is necessary to support the total measurements of the system. As new technology emerges such as solar-powered roof tiles from Tesla, the total lifetime value of the solar system may increase.