Power Optimizers: What are they?

Power optimizers are important elements in present-day solar power systems that play a major role in improving the efficiency of solar panel systems. Also, these are equipped with central string inverters to transform the DC (direct current) electricity generated by the solar panels into consumable AC (alternating current) power for people to use.

Exploring deeper into this review helps you gain useful knowledge about what exactly is a power optimizer, how it works, and the installation process, advantages, and disadvantages. Furthermore, you can find out if power optimizers are worth it by comparing them with microinverters.

What are Power Optimizers?

Power optimizers keep track of each solar module’s maximum output and automatically adjust the voltage before the power is supplied to a central inverter. Also, these optimizers are highly useful in some shaded conditions or under multiple roof orientations for solar panels.

However, these optimizers allow insight into the performance of each panel and are well-suited to be paired with home energy storage systems.

Most often people get confused between power optimizers and solar inverters. To explain the concept simply, a power optimizer isn’t an inverter. Rather they are available as a small box that is plugged into your solar panel’s DC cables and AC output.

In comparison with solar trackers (which allow panels to move and follow the sun), these power optimizers are different and are installed on every solar panel. They are designed to ensure optimal performance of both shaded and unshaded panels, providing the best possible power output from the entire system.

Most importantly, microinverters replace the requirement of a large, central inverter by performing the DC-to-AC conversion process at each panel, whereas the power optimizers can work in conjunction with the central string inverters to enhance the power output. Rather than converting the DC power into AC power on the panel space like a microinverter, power optimizers improve the DC power’s quality and send it to a central device called a string inverter that turns it into AC power.

How Do Power Optimizers Work?

Power optimizers, also known as DC optimizers, adjust the voltage and current of each solar panel to ensure maximum output. Let’s assume the voltage or current isn’t at the required level. In that case, the optimizers will adjust it so that the solar panel operates at its peak level. This can be accomplished by adjusting the solar panel’s voltage and current using the DC-to-DC converter.

The DC-to-DC converter works by obtaining the input voltage and current to convert to the desired output and voltage. As a result, the power optimizers can adjust the solar panel’s output to match the optimal output for the given conditions.

These power optimizers utilize a technique known as MPPT (Maximum Power Point Tracking) to monitor the total output of the array and continually adjust the presented load to keep the system operating at its peak efficiency point. Hence, this is made possible by adjusting the voltage before the power is sent to a central inverter.

As a result, the MPPT technology allows for the improvement of solar panel power output by monitoring the maximum power point, guaranteeing higher energy gain, efficiency, and ability to adapt to environmental changes.

Advantages of Power Optimizers

These are the key benefits of DC power optimizers:

• Increased efficiency in partially shaded conditions: DC Power Optimizers allow you to generate additional energy if your panels are partially shaded or facing different angles. It means that even if one panel is shaded, the other set of modules performs at its peak level and is beneficial on irregularly shaped roofs.
• Individual-level panel monitoring: Power optimizers are one type of Module-Level Power Electronics (MLPE) device that tracks and stores the produced solar energy production data like output voltage and peak efficiency from each PV module. You can track the financial and power performance report in a real-time app where you can receive instant notifications. Also, you receive an alert if your system doesn’t perform well due to the present weather conditions. This helps you contact your installer and plan for further check-ups on your system.
• Compatibility with DC-coupled battery options: DC-coupled charging solutions provide electricity from your power-optimized solar panels directly to your battery storage and the transfer process occurs before your inverter converts the DC power into AC power for home use. In other words, the DC output from solar panels is fed to the battery storage as both these devices are commonly operated on DC electricity.
• Reduced inverter size: The voltage tracking and cleaning occurs at individual panel levels and the inverter connected to power-optimized solar modules isn’t compulsory to be large, thereby saving your house space and enhancing aesthetic value.
• Potential for system oversizing: You can connect a large-sized solar array to your inverter to maximize energy production during peak times. But, your system needs to be carefully designed to connect with inverters that can convert AC power within a specific limit.

Disadvantages of Power Optimizers

These are the main drawbacks of power optimizers:

• A limited selection of inverters: Since power optimizers are newly introduced devices to the market, it is difficult to find the perfect solar inverter that can be paired with the system.
• Higher initial costs: Preferring a power optimizer increases your overall installation cost a bit higher when compared to the standard string inverter solar panel system. This is because you have to install a single optimizer per solar panel. However, these optimizers are cheaper than microinverters and contribute to long-term savings, thereby making these higher initial costs worth the peak performance during shading.
• Potential scalability issues in future expansions: Since power optimizers are attached to central inverters, there are limitations to handling the power which makes it difficult to expand the system for future use. Clipping occurs when your solar panels produce more electricity than the inverter can handle, which leads to huge power losses.

How to Install Power Optimizers?

Here is the step-by-step process of installing power optimizers:

1. Shut down your main power to ensure your safety while handling the wires.
2. Set up your power optimizers near your solar panels and securely mount them.
3. The DC cables of your solar panel should be connected to the optimizers in such a way that the positive and negative terminals match each other.
4. Attach the optimizer to the inverter so that the DC power gets converted into AC power to operate your home appliances.
5. Most importantly, you need to make sure that the cables are tight and safe and always use proper tools by following each step during installation by taking your convenient time.

You can install power optimizers in any orientation which makes them incredibly flexible even if it is installed on complicated roofs with partially shaded conditions. Mainly, the DC optimizers should be installed with a minimal distance between each other for easier cable connections. For heat dissipation clearances, make sure to maintain a minimum gap of one inch between the power optimizers and other surfaces.

A site survey is one of the most important steps before installing the solar panel system to select the most efficient modules based on your requirements. Especially, the placement of solar panels, their direction, orientation, and the intensity of sunlight play a significant role in figuring out the maximum energy you can generate from the sun. As a result, it is recommended to use design tools to measure the size of your inverter and power optimizer to ensure high compatibility.

Power Optimizers vs Microinverters

The comparison between power optimizers and microinverters is based on the following factors:

1. Module Level Monitoring Capabilities: Both microinverters and power optimizers support monitoring the module level power and the performance of the panels. In simpler words, you can keep a track record of the energy produced by each panel that helps to find out the issues with your solar panel system.

2. Solutions for complex roof layouts and shaded conditions: Despite having a flexible system design, microinverters are more complex to install on roofs than string inverters or power optimizers. However, microinverters and power optimizers help to improve the overall performance of solar panels on complex roofs or roofs with excess shading. Even if a single panel is shaded, these devices ensure every panel produces maximum power, the DC electricity, and gets converted individually to AC electricity.

3. Cost: Compared to microinverters, power optimizers are available at a reasonable cost despite having similarities in terms of initial investment, installation costs, and efficiency, thereby providing a more cost-effective option for homeowners with budget constraints.

4. Scalability: Microinverters have higher scalability by allowing you to simply add another panel. Although power optimizers offer the best option to expand the solar system, you need to make sure that the central inverter can handle additional input.

5. Compatibility with battery storage solutions: Both microinverters and power optimizers offer the best compatibility with battery storage solutions. However, you should choose a particular type of inverter if you require a DC or AC-coupled battery solution. Microinverters are suitable to work only with AC-coupled batteries whereas power optimizers rely on a central inverter to perform the DC to AC conversion at each solar panel.

Are Power Optimizers Worth It?

Overall, power optimizers are worth your investment for solar systems in both homes and businesses, especially, if your panels are subjected to mismatch loss due to degradation, partial shading, or manufacturing faults. These optimizers boost the efficiency of your panels oriented at different angles. Furthermore, power optimizers guide you to understand the workings of every individual panel and monitor its performance so that you can easily evaluate and fix panels.

Mainly, you need to carefully consider site-specific factors and potential future needs when deciding between power optimizers, microinverters, and traditional string inverters. Since each inverter has pros and cons, you need to select the perfect one depending on your system design and capacity. For example, microinverters are more efficient than string inverters for installation with fluctuating sun conditions. If the string inverters are equipped with power optimizers, you can almost match the individual panel performance of microinverters.

Conclusively, power optimizers can be a smart choice and the final decision varies based on every individual’s specific needs and situations.