Optimizers Vs Microinverters: How to Choose?

Home Optimizers Vs Microinverters: How to Choose?
07/09/2022
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One of the important choices that must be made when installing a solar panel system for the house is the kind of inverter to use. The solar panels generate direct current (DC) energy, which inverters turn into usable alternating current (AC) electricity. Inverters are the second-most crucial piece of equipment in the solar power system after the actual panels.

For the solar energy system, one can choose from three different types of inverters: string (also known as centralized) inverters, power optimizer systems (also known as string inverters + power optimizers), and microinverters. “Module-Level Power Electronics” or MLPEs are a general term for microinverters and power optimizers.

What Is an Optimizer And How Does It Work?

Solar power optimizer
Source: Pinterest

The power optimizers are positioned at each solar panel to provide a hybrid solution between a typical string inverter and microinverters. They “condition” the electricity generated by the solar panels by adjusting the voltage before transferring it to the inverter for conversion. 

It’s important to note that power optimizers require a centralized string inverter to manage the conversion process because they cannot function as an inverter on their own. 

Systems using power optimizers have a unique optimizer component for each panel, similar to micro inverters. However, they “condition” the DC electricity and transmit it to a string inverter for conversion rather than converting the DC current to AC electricity right at the panel site. 

The panel-level optimization provided by power optimizers generally results in higher system efficiency than utilizing a string inverter alone if the roof receives shade during the day. Power optimizers, like microinverters, allow panel-level performance monitoring in addition to minimizing the effect of panel shading on system performance.

Pros And Cons Of Power Optimizers

Solar power optimizer circuit
Source: Pinterest

The optimizers might have certain advantages and disadvantages as well. Therefore it is significant to know about them before purchasing. 

Pros

  • When the panels are partially shaded or facing different directions, they can generate much more electricity by using power optimizers.
  • They are able to gather and transmit information about each PV module’s peak efficiency and output voltage to the cloud, where it is sent back in real-time along with financial and power performance statistics.
  • The inverter connected to power-optimized solar modules doesn’t need to be as big because the voltage tracking and cleaning happen at the level of the individual module. This will be more aesthetically acceptable, just free up some space around the garage or exterior wall of the house.

Cons

  • The market for power optimizers is quite new. Since there are very few manufacturers of the power optimizer, there’s a lack of model variety.
  • The installation expenses will be a little more than with a standard string inverter solar panel system because power optimizer equipment is installed on every solar panel.

What Is Microinverters And How Does It Work?

A microinverter
Source: Beny

Microinverters are commonly mounted on the back of each solar panel in systems. They eliminate the need for a separate string inverter by converting the DC electricity from the solar panels into AC electricity on the roof. The standard microinverters can also be installed on the solar racking system right next to the panel.

These inverters bring MLPE to its logical conclusion: whereas power optimizers combine the solar panels’ electricity and send it to a string inverter for the DC to AC conversion, microinverters perform the DC to AC inversion at each individual solar panel. Consequently, microinverters provide the same ability as power optimizer systems to check the efficiency of certain solar panels.

Pros And Cons Of Microinventors 

Beny Microinverter
Source: Beny

Similar to other inverters, microinverters have certain pros and cons that should not be missed out on.

Pros

  • Individual per-panel monitoring made possible by microinverter systems can enable solar panel owners or solar panel installation businesses to learn about underperforming systems so they can take action rather than letting potentially underperforming panels go unreported.
  • The majority of high-quality microinverters have gone through extensive testing in adverse weather.
  • Microinverters immediately convert DC power to AC, protecting users from high voltage DC electricity.
  • As opposed to string inverters’ 5-year warranty, microinverters often have a 25-year warranty.
  • In the long run, a superior value and investment.

Cons

  • Theoretically, compared to a string inverter with a single point of failure, the inverters have a twenty times greater likelihood of experiencing the same failure rate. 
  • In contrast to a string inverter failure, which results in a system failure, a single microinverter failure only affects the solar panel to which it is connected. 
  • A micro inverter solar panel system will also initially cost a little bit more money out of pocket because it has more components.

Power Optimizers Vs MicroInverters: Common ground

Solar PV Installation
Source: Pinterest

Power optimizers and microinverters aid in enhancing the performance of solar panels installed on complex or partially shaded rooftops.

Compare the number of kilowatt-hours (kWh) produced by each solar panel in the array using power optimizers and microinverters, which both track the performance of individual solar panels.

On the back of each individual solar panel, a single MLPE (microinverter or power optimizer) is typically installed by solar businesses. In other words, if the system has 20 solar panels, it probably also contains 20 microinverters or 20 power optimizers.

Differences Between Microinverters and Optimizers

Microinverter and Optimizers on Solar panels
Source: Pinterest

While power optimizers and microinverters have a lot of common grounds, there are also a lot of distinctions between the two technologies, which are covered in more detail below:

The transition from direct current (DC) to alternating current (AC)

At the panel site, microinverters transform DC energy into AC energy. Power optimizers are also installed behind solar panels, but they don’t perform the actual conversion; rather, they “condition” the DC energy before sending it to a central inverter to complete the task. The DC energy’s voltage is fixed during the conditioning process, allowing the centralized inverter to transform the DC energy into AC energy more effectively.

Warranty

Power optimizers and microinverters both have 25-year guarantees. Although optimizers have a 25-year warranty, the centralized inverter with which they are paired could have a shorter warranty. An extended warranty for the central inverter is frequently provided by installers, either for free or at an additional cost.

A company’s warranty terms should also be carefully examined to see what is and is not covered. Does the business pay for the shipping of the components, replacement labor, and installation labor? And how long does it take to submit a claim for a warranty? These are all crucial factors to take into account when deciding which kind of inverter to install on the property.

Maintenance

It is important to take into account whether and how frequently microinverter and power optimizer systems will malfunction over their lifetimes, as well as the effects of an improbable failure on the output of the solar panel system. Given the labor needed to get access to and work on the roof, it will probably be more expensive to replace a microinverter or a power optimizer positioned on a roof than it will be to replace a string inverter on a wall at ground level.

However, that only makes up a portion of the equation involving lifetime maintenance costs. Leading microinverters have warranties that last for 25 years, but many string inverters only have warranties that last for 12 years, so there is a need to replace them sooner rather than later.

Battery Choices

Power optimizers and microinverters can both work with battery storage. However, there might be a need to utilize a certain kind of inverter depending on the requirement whether it is a DC or AC-connected battery solution. The ideal inverters for the chosen battery should be discussed with the installer or electrician if battery storage is a concern.

Things To Consider Before Purchase 

There are several factors that should be considered before purchasing power optimizers or microinverters such as their efficiency, warranty, size, and price. 

Efficiency- Different optimizers have different efficiencies. The ones with a higher efficiency enable an increase in the efficiency of the electrical system as well, furthermore, leading to better solar production. 

Warranty- While most of them have a 25-year warranty, the different manufacturers have different offers. Thus it is important to read the manual and make a comparison between the warranty. 

Size- The varying sizes of the inverters or optimizers also determine the voltage they can carry. Purchase the size that best suits the business requirements. 

Price- Although not considered an expensive part of the electrical systems, prices should still be compared. The ones with higher efficiency and size might often come at a good cost. 

Conclusion 

Community solar projects with microinverters
Source: Pinterest

Both micro inverters or power optimizer systems have efficiency levels that are fairly similar, are useful for tracking the performance of individual panels, and can help maximize energy production on complex or weakly shaded roofs. The greatest choice ultimately depends on preferences.

It’s vital to remember that microinverters come with longer warranties as opposed to string inverters and they help eliminate the high exposure to DC electricity. For further microinverters and optimizers, and solutions refer to Beny.com.

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