Use of solar panels has become very common. The reason is that they offer free ways to generate electricity, reducing bills. However, these panels require inverters, which convert DC solar power to AC for domestic use. Among different inverters, MPPT vs PWM solar inverters are very popular.
Interestingly, some people consider PWM a superior option primarily because it is lower cost. The majority of people favor MPPT because of its top-notch performance and high power utilization from solar. In this article, I will compare MPPT and PWM solar inverters head-to-head. You’ll learn which of these two inverters is a suitable option for you. So, let’s get started.
What are MPPT & PWM Inverters?
An MPPT (Maximum Power Point Tracking) inverter is a smart inverter that extracts the maximum possible power from solar panels. It continuously adjusts the voltage and current to find the optimal operating point of the solar system. But a PWM (Pulse Width Modulation) inverter controls charging by matching the solar panel voltage with the battery voltage. It reduces excess power as the battery fills up.
In other words, PWM is a simple form of the inverter. It works in a very straightforward way. Actually, a PWM inverter takes power from the solar panel. Then sends it directly to the battery. But often, you see that solar panels produce a higher voltage than the battery needs. Right? The PWM system reduces that extra voltage by adjusting how much power is allowed to pass through.
Simply put, PWM reduces excess energy from solar panels so the battery gets only what it can safely handle. On the flip side, MPPT is a highly advanced inverter. It does not send solar power directly to the battery. Instead, it first analyzes how much power the solar panel can produce at that moment. As you know, solar panels produce different amounts of energy depending on sunlight.
So, the MPPT keeps adjusting itself to find the best point at which the panel produces maximum power. Once it finds the best point, the inverter converts excess voltage into extra charging current. It means that even if the solar panel produces more voltage than the battery needs, the MPPT does not waste it. Instead, it transforms that extra energy into usable power for your devices.
Differences Between MPPT & PWM Solar Inverters
Now there are two other inverter types, MPPT and PWM, that are known for their reliability. But as you know, they work in different ways. This makes them vary in several other aspects as well. Want to know how? Here, I will discuss the key factors in which MPPT and PWM differ.
1- Technology Type
The first thing that distinguishes MPPT from PWM is the technology used to manage solar power. MPPT uses modern and advanced technology. As you know, it works like a smart system that constantly monitors and adjusts the power output from the solar panels. For this tracking, there is always a need for advanced technology. On the other hand, PWM is an older and simpler technology. It does not need to make smart adjustments or track maximum power. Instead, it is only responsible for controlling the flow of electricity between the solar panel and the battery. All this doesn’t require complex technology use.
2- Power Utilization
This difference shows how much of the solar energy your appliances use without waste. In this term, MPPT is a clear winner. It intelligently tracks the maximum power point of the solar panels. It means MPPT adjusts voltage and current in real time so that the system can extract almost all available energy. All this ensures there is no energy waste. But PWM has lower power utilization. Its job is not to optimize solar output, but to just match the solar panel voltage with the battery voltage. So when solar panels produce more energy, it will be wasted. PWM cannot use it fully.
3- Energy Conversion
Energy conversion is another important factor to consider when choosing between MPPT and PWM inverters. These factors indicate how well the inverter turns sunlight into useful electricity. As previously mentioned, MPPT converts energy efficiently. It first analyzes the solar panel’s output and then adjusts voltage and current to get the highest possible power.
If the panel produces extra voltage, MPPT does not waste it. Instead, it converts that extra voltage into additional charging current that you can use. But PWM is not very efficient at energy conversion. It directly connects the solar panel to the battery and then reduces excess voltage to match the battery’s voltage. As a result of this energy conversion method, energy is also wasted.
4- Battery Charging Speed
When it comes to charging the battery, the MPPT inverter wins the debate. The reason is that it is highly efficient, enabling high-speed charging. Interestingly, it extracts maximum power from the solar panels and converts excess voltage into usable charging current. This means more usable electricity is sent to the battery in less time. There is no power waste during this process or operation.
Even when sunlight is insufficient, the MPPT will adjust to charge the battery. Conversely, PWM inverters lag in charging the battery. They cannot fully optimize solar power. They just match the solar panel voltage with the battery voltage. This often limits the amount of energy transferred at a time. As a result, some potential charging power is lost. If you want to charge a battery quickly, you should choose MPPT over PWM.
5- Weather Performance
The weather remains changeable all the time. So it highly affects the inverter you use. For example, MPPT inverters perform very well in changing weather conditions. Why? Because they constantly track the maximum power point of your solar panels. Now, as sunlight rises or drops, the MPPT automatically adjusts the voltage and current to achieve the best possible output. So even on cloudy or partly sunny days, it still tries to extract as much energy as possible. But PWM inverters do not perform as well in changing weather. They can’t adapt to changing sunlight conditions. So when sunlight is weak, energy is lost, and overall performance becomes lower.
6- System Size Usage
The size of the solar system you have also strongly affects the choice of inverter, MPPT, and PWM. For example, if you have a medium- to large-sized solar system, MPPT inverters are best. They can handle higher power loads and make full use of large solar panel arrays. Also, these MPPT inverters can manage changing voltage and current. Even this split inverter can handle 16 units in parallel operation. It means it performs very well when multiple panels are connected. However, PWM inverters are a good choice for small solar systems. Actually, when the solar panel size is small, the battery voltage closely matches the panel voltage. It’s where PWM performs very well.
7- Voltage Handling Ability
It means how an inverter manages the different voltage levels from solar panels. So this is another big distinction between MPPT and PWM. For example, PWM inverters have limited voltage-handling capability. They work best only when the solar panel voltage is very close to the battery voltage. If the panel produces a higher voltage, the PWM system will reduce it to match the battery level.
On the other hand, MPPT inverters can handle a wide range of input voltages. It means that even if the solar panel voltage rises or falls, the MPPT system will still adjust it properly. It does not waste extra voltage.
8- Price Range & Long-Term Performance
Lastly, PWM and MPPT differ significantly in terms of overall price vs. long-term performance. First, if I discuss MPPT, there’s no doubt it’s very expensive because it uses smart technology. But this higher price justifies its long-term performance. MPPT can produce more electricity from the same solar panels and has higher efficiency.
This helps save more energy over time, reducing your electricity costs. On the flip side, PWM has a lower initial cost due to its basic design. But when it comes to long-term performance, it is not handy. It wastes some solar energy during operation. So you get less overall solar power, which might increase your electricity costs. Therefore, I always suggest keeping both factors in mind when making the final choice.
Következtetés
Still confused about which of these two options is best for you? I recommend choosing MPPT solar inverters. Why? The reason is that these inverters have excellent efficiency. This means they will use the maximum power produced by the solar panels and convert it to AC. This means no power produced by solar will be lost.
However, if you have a tight budget, a PWM solar inverter can be a good starting point. To increase output, you’ll need to use more solar panels. The reason is that these PWM solar inverters can waste some power during their operations. To compensate for this, a higher number of panels becomes necessary. In this article, I have discussed all the differences between these two solar types.