If you’re thinking of going solar, chances are good that the first step you’ll take is to decide on the technology you want to use, which is most likely either an MPPT or PWM solar inverter. Both types exist to convert the energy from your solar system to use in batteries, appliances, or indeed to feed back into the grid. The difference between the two is how that energy is transferred and how efficiently it is being utilized, which may be different depending on location or other variables.
In a state like Assam, where the atmospheric conditions can vary and every kilowatt counts, selecting the proper inverter technology is imperative. The difference between MPPT and PWM variation can affect how much energy is being utilized, how long the batteries themselves last, and perhaps more importantly, how much you will save in the end.
This blog provides a straightforward comparison of both technologies, explaining clearly the facts so you can make the best decision regarding the ideal solar inverter technology for your home or business.
Whether you’re building a simple off-grid set-up or laying out a larger expense, knowing the advantages of MPPT solar inverters and how they measure up to PWM can help you get the most bang for your buck. Now, let’s look at the efficiency difference PWM vs MPPT and get an idea of what it all means in terms of long-term value.
An Introduction to Understanding: What is MPPT and PWM?
To make an informed decision to install an inverter, an individual should first understand how these two technologies work.
PWM means Pulse Width Modulation. It is an older, simpler, and much more rudimentary technology. PWM connects the solar panels directly to the battery bank. A PWM slowly decreases the amount of power to the batteries as they approach full charge so there is no risk of overcharging the batteries.
PWM inverters are generally quite reliable and inexpensive; however, they do suffer from a major disadvantage, which is that they will burn a fair amount of energy because they actively force the solar panel voltage to match the battery voltage, which causes PWM to lose efficiency, especially if your panel voltage is higher than the battery bank voltage.
Conversely, MPPT, which stands for Maximum Power Point Tracking, is a more advanced and efficient system. MPPT continuously adjusts to track the voltage and current coming off the solar panels and finds the ash “sweet spot” where the solar panels are generating the most power. Then, the MPPT inverter will convert that voltage to that of the battery, so you use the maximum amount of power available to you from the solar panels. Simply put, MPPT ensures you’re squeezing every last drop of power from your solar panels.
MPPT vs PWM Solar Inverter: Which Performs Better?
When it comes to efficiency, there is one clear winner: an MPPT. MPPT inverters can give you 20% to 30% more performance than a PWM, especially in colder weather, low light conditions or when the panels are partially shaded. The reason is simple: MPPT controllers are constantly adjusting to the ever-changing conditions to enhance each ray of sunshine.
Though it works, PWM is a little stiffer, and if the sun is not beating down or the solar panels are not exactly matched to your batteries, the PWM system will underperform. For that reason, PWM is usually a system recommended for small systems with low energy demands and a near-perfect sun, small off-grid cabins, remote lights, and even rural systems.
At the same time, MPPT inverters are suited for larger systems or installations, or where the weather patterns are more unpredictable. If the panels will be shaded for portions of the day, or if your energy needs are high and fairly consistent, an MPPT system will be more reliable with better output than a PWM solution.
The advantages of MPPT Solar Inverter: Why it’s the best choice
One of the key benefits of an MPPT solar inverter is that it keeps working effectively all day long, even if the sun is not at its best. You can use it freely in the morning and evening or during cloudy days, as the MPPT will adjust continuously to extract optimum performance. This means more power generated over time and in terms, better returns on your investment.
The other main advantage is flexibility. With an MPPT solar inverter, you can connect a wider variety of solar panels. MPPT solar inverters can work with solar panels associated with higher voltages, or to wire your solar panels with more combinations or different designs. This flexibility makes for an easier installation and is efficient for the various aspects of installing on rooftops, even with a few space limitations.
MPPT also allows for longer cable runs between panels and controllers with less power loss, which is beneficial for larger systems. Further, by using the available voltage better, MPPT will charge your batteries faster, which helps extend their life.
Considering Cost: Is MPPT Worth the Additional Cost?
There is no getting around it, MPPT inverters come with a greater upfront cost than PWM inverters. However, the real question is whether you will recoup that additional cost over the life of the inverter. In most cases, you will.
Since MPPT inverters are more efficient, they will produce more usable power. Converting that usable power into your actual cost savings will take some months and years of using your system.
A little bit of power savings adds up month-over-month, which equates to energy bill savings, battery lifespan savings, and service maintenance, particularly if you live in an area of inconsistent sunlight, such as during Assam’s monsoon season. MPPT helps stabilize energy production.
However, if you have a small budget and minimal power needs for now, you may find that PWM will suffice for your immediate needs. For example, if you have a solar light setup or a small off-grid home and have no plans for growth in your solar system, the lower initial cost of PWM inverters may still make them the more sensible option.
Comparison of Solar Inverter Types: Which Type is Right for Your Set Up?
Let’s address this question with real-world scenarios.
For instance, if you’re installing a small solar system supplying some lights and a fan and the voltages on your panels and batteries match, then a PWM is all you require. Such set-ups are usually price sensitive and the energy load is usually low. For example, if you are in a remote area, where price is more important than peak efficiency, PWM makes sense.
However, if you are considering a solar system that powers the majority of your house, e.g. a refrigerator, a washing machine or an air conditioner, then MPPT is a better initial investment. The system will be more adaptable to changing weather, panel orientation and battery levels.
For this scenario, MPPT also allows for future growth. In the future, if you want to add more panels, or upgrade your batteries, or even change to a hybrid system, MPPT technology makes it much easier to accommodate the changes.
Efficiency and Energy Yield: PWM vs MPPT Efficiency in the Real World
Let’s now address one of the most common questions: just how much more efficient is MPPT compared to PWM?
In the real world, MPPT inverters will provide an energy yield of 15% to 30% more than PWM. The exact number varies based on several factors, including the weather conditions, the temperature of the panels, the time of day, and shading. For example, the actual capacity of solar panels in cooler temperatures is usually higher than in warmer temperatures. PWM systems can’t take that into account, while MPPT does.
The benefit of this efficiency is explicitly shown in larger systems where a modest efficiency can make a huge difference in energy use over time. More energy means more charge into batteries, more time between charges, and less electrical dependence on the grid or generators. This can end up being a significant difference in commercial setups or large home usage.
Mistakes to Avoid
One of the most common mistakes that people make when comparing MPPT vs PWM solar inverters is to choose one or the other primarily based on price. This is understandable; solar components can be costly, but in many cases, people opt for the cheap inverter and end up disappointed with performance years later.
Another mistake is to match the solar panel voltage to the battery bank in a PWM system. Remember, PWM works best when the panel voltage is very close to the battery voltage. When it is not, a lot of the potential power will be wasted.
Yet another mistake people make is to buy cheaper, low-quality MPPT controllers just because it says “MPPT” on it. Many of the cheaper controllers are really just poorly functioning PWM devices with very poor tracking algorithms that were just marketed as MPPTs to sell more controllers. Always look for reputable brands and reputable suppliers that guarantee the quality of their products.
Which One Should You Select?
Ultimately, your choice between MPPT vs PWM solar inverter should take into account your power requirements, geographic location, budget, and longer-term visions for the project. If you have a small system, low energy consumption, and a limited budget, then a PWM may do the trick. However, if your aim is greater efficiency, room for growth, and stable long-term performance, then an MPPT inverter is the right option.
In this case, you get what you pay for; an MPPT solar inverter is more expensive, but brings a much larger value, relative to energy output, battery life, and overall system flexibility.
Conclusion
The critical component of a solar setup is the inverter. MPPT vs PWM solar inverter technology is not only a technical choice, but a sound investment into your energy future. A good choice can mean more power, improved battery life, and long-lasting savings that will add up.
At Solar Prabha in Guwahati, we recognize that every home and business in Assam has its own energy demands. Our solar solutions and knowledgeable support staff are customized to fit your location, energy demands, and budget. If you are interested in solar at the beginning of your journey, or if you are ready to install, we will help guide and support you every step of the way.
Contact us today at +91-7099030047, or visit our office and meet our friendly staff.
