Solar inverters are a central component to utilizing solar energy. However, unlike photovoltaic (PV) solar panels, which can last for decades with minimal maintenance (with only 0.5% output degradation per year), solar inverters have a finite lifespan. In this article, we&#;ll tell you how long an inverter lasts and how you can estimate the lifespan of the inverter you&#;re considering.
Goto Senergy to know more.
Solar panels are the power-generating part of a solar PV system and are relatively simple, reliable devices with no moving parts or other wear-prone components. The energy they derive from exposure to the sun is fed into a 12-volt battery bank.
Energy is stored in this deep-cycle lead-acid battery bank, so power is available when the panels are not generating current. How long will a deep-cycle battery bank provide power? The length of the battery run and power demand determines the discharge rate, along with the condition of the batteries.
For instance, a 600-watt solar panel can charge a 12V, 100ah battery with about three hours of sunlight. Panels of that size can usually provide over 180 amp-hours per day.
Inverters utilize a small portion of the deep-cycle battery power to operate, converting the Direct Current (DC) to Alternating Current (AC), making it usable for homes and businesses.
What Capacity Inverter Do You Need for Your Solar System?
The total capacity of the inverter(s) should be equal to the power-generating ability of the solar panels. Assuming a typical service of 100 amps, if your solar panel array can generate watts, you should purchase at minimum, a watt inverter.
In order to convert the current from DC to AC, inverters employ components such as:
, to filter fluctuating electrical current on DC lines
, such as MOSFET semiconductors, to convert DC to AC power
, such as the inductor and transformer to filter and smoothen electrical wave shapes for current compatibility with grid connection
You Could be Saving 90% on Your Electricity Bill
Schedule your free on-site consultation today and find out how much you can save from day 1.
Learn More
How Long Do Inverters Last?
Depending on the type, an inverter can last up to 25 years. Others can fail after only a few years.
All of the above components in an inverter are subject to electro-mechanical wear and temperature fluctuation stresses. In the case of capacitors, electrolyte evaporation is also a concern. Other causes of wear include:
Over and under-voltage
Over-current
Ultrasonic vibrations originating from the cores of inductive components
An inverter can fail outright if one or more components stop working, or it can cross a threshold of efficiency degradation, where it is no longer passing enough AC current to be viable. In both cases, the inverter must be replaced.
External Factors Affecting Lifespan
As you can see, inverters are subject to a much greater variety of potential wear variables than the solar panels themselves. The specific wear not only varies types of inverters, but it also depends on:
Whether or not they are exposed to the elements
How much maintenance was performed over their lifetime (such as keeping vents clear for proper heat dissipation) and
Other factors that affect their
life expectancy
So, how long do inverters last? All of the above factors must be taken into account before answering that question, along with the inverter&#;s daily run time, which can differ according to where you are based and how much sun you receive.
We haven&#;t quite answered the &#;how long do solar inverters last&#; question yet, because there is another factor that we must consider, and that&#;s the type of inverter we&#;re dealing with.
How Long Does an Inverter Last
? It Depends on the Type of Inverter
String inverters are a cost-effective solution because only one inverter is required for a large array of solar panels, typically 5-10 panels in total. This simplicity also makes them easy to install and troubleshoot.
However, a string inverter can only deliver as much power as the weakest-performing solar panel in the array. Therefore, if one panel is shaded or covered in debris, the entire system is affected. Another disadvantage is that they are typically warrantied for only 8-12 years, which is less than half that of microinverters, which gives you an idea of their expected lifespan.
Microinverters are smaller inverters and are usually installed as one per solar panel. They function in a parallel circuit, so if one solar panel is obstructed or defective, it won&#;t affect the rest. In theory, then, a microinverter-equipped array can deliver consistently reliable power under most conditions. Another advantage is the longevity, with many having a 25-year warranty, though failure is possible before the warranty expires.
Here&#;s a chart of solar inverter warranties to give you some ballpark estimates:
Inverter Type Typical Warranties
String Inverter
Are you interested in learning more about 5 kw inverter? Contact us today to secure an expert consultation!
5-12 years
Microinverter
20-25 years
DC Optimizers
20-25 years
Central Inverters
5-10 years
Battery Based Inverters
2-5 years
Other Considerations
Modified sine wave inverters make a more abrupt switch in polarity, so the sine wave has a stair-step pattern rather than smooth. Pure sine wave inverters apply a smooth curve to the AC current wave as the polarity switches back and forth.
Why is this important? This affects not only the lifespan of the inverter but has the potential to reduce the lifespan of your equipment.
Finally&#;
How Long Does an Inverter Last
?
The answer is&#; it depends. We hope we&#;ve given you a good idea of the variables involved, and how difficult it is to predict the lifespan of an inverter. With good maintenance and minimal exposure to harsh conditions, inverters should reach the upper end of the time spans listed above.
With + projects completed successfully, we certainly know how to install reliable solar power systems. Talk to us or send us a message to learn more about commercial and residential solar systems.
In the first part of this series, pv magazine reviewed the productive lifespan of solar panels, which are quite resilient. In this part, we examine residential solar inverters in their various forms, how long they last, and how resilient they are.
The inverter, a device that converts the DC power produced by solar panels into usable AC power, can come in a few different configurations.
The two main types of inverters in residential applications are string inverters and microinverters. In some applications, string inverters are equipped with module-level power electronics (MLPE) called DC optimizers. Microinverters and DC optimizers are generally used for roofs with shading conditions or sub-optimal orientation (not south-facing).
The technology ensures that each panel produces its max capability real-time and isn&#;t limited to the weakest link in the chain or &#;string.&#; String inverters are subject to the &#;Christmas light&#; effect where if one panel is not performing or is shaded, the rest of the panels connected in series will be limited to that panel&#;s production level.
Some string inverters are equipped with a bypass diode, a technology that prevents the &#;Christmas light&#; effect from taking place altogether, shown here by Fronius.
In applications where the roof has a preferable azimuth (orientation to the sun) and little no shading issues, a string inverter can be a good solution.
In a string inverter, there is generally less complicated wiring and a centralized location for easier repairs by solar technicians. Typically they are less expensive, said Solar Reviews. It said that inverters can typically cost 10-20% of the total solar panel installation, so choosing the right one is important.
How long do they last?
While solar panels can last 25 to 30 years or more, inverters generally have a shorter life, due to more rapidly aging components. A common source of failure in inverters is the electro-mechanical wear on the capacitor in the inverter. The electrolyte capacitors have a shorter lifetime and age faster than dry components, said Solar Harmonics.
EnergySage said that a typical centralized residential string inverter will last about 10-15 years, and thus will need to be replaced at some point during the panels&#; life.
String inverters generally have standard warranties ranging from 5-10 years, many with the option to extend to 20 years. Some solar contracts include free maintenance and monitoring through the term of the contract, so it is wise to evaluate this when selecting inverters.
Microinverters have a longer life, EnergySage said they can often last 25 years, nearly as long as their panel counterparts. Usually, these inverters have a 20&#;25-year standard warranty included. It should be noted that while microinverters have a long warranty, they are still a relatively new technology from the past ten years or so, and it remains to be seen if the equipment will fulfill its 20+ year promise.
The same goes for DC optimizers, which are typically paired with a centralized string inverter. These components last for 20-25 years and have a warranty to match that time period.
Failures
A study by kWh Analytics found that 80% of solar array failures occur at the inverter level. There are numerous causes of this.
According to Fallon Solutions, one cause is grid faults. High or low voltage due to grid fault can cause the inverter to stop working, and circuit breakers or fuses can be activated to protect the inverter from high-voltage failure.
Sometimes failure can occur at the MLPE level, where the components of power optimizers are exposed to higher temperatures on the roof. If reduced production is being experienced, it could be a fault in the MLPE.
Installation must be done properly as well. As a rule of thumb, Fallon recommended that the solar panel capacity should be up to 133% of the inverter capacity. If the panels are not properly matched to a right-size inverter, they will not perform efficiently.
Maintenance
To keep an inverter running more efficiently for a longer period, Those Solar Guys recommended choosing a cool, dry place with lots of circulating fresh air. It also suggested avoiding installing in areas with direct sunlight, though specific brands of outdoor inverters are designed to withstand more sunlight than others. And, in multi-inverter installations, it is important to be sure there is proper clearance between each inverter, so that there isn&#;t heat transfer between inverters.
Those Solar Guys said it is best practice to inspect the outside of the inverter (if it is accessible) quarterly, making sure there are no physical signs of damage, and all vents and cooling fins are free from dirt and dust.
It is also recommended to schedule an inspection through a licensed solar installer every five years. These standups typically cost $200-$300, though some solar contracts have free maintenance and monitoring for 20-25 years. During the checkup, the inspector should check inside the inverter for signs of corrosion, damage, or pests.
In the next installment of the series, pv magazine will examine the life of residential battery energy storage applications.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: .