How Expensive Are Solar Inverters? All You Need to Know Before Buying an Inverter for Your Solar Setup

s we continue to explore the world of renewable energy and sustainable living, more and more people are turning to renewable energy sources to power their homes and businesses. One of the most popular ways to do this is by harnessing the sun’s power with solar PV systems, but what many people may not realize is that a critical component in making this happen is a solar inverter.

Think of the solar inverter as the "brain" of your photovoltaic system since it plays a vital role in converting the power generated by your panels into a form that can be used by your home. Without this essential piece of equipment, the energy produced by your solar modules would be like trying to light up a room with a bare bulb - pointless.

But, like most essential things in life, inverters come with a cost. They can be quite expensive, and it's important to understand what you're getting for your money and what to look for when making a purchase. In this article, we'll dive deeper into the functions of solar inverters, the different types available, and the associated costs so you can make an informed decision when it comes to powering your home with solar energy.

What is a solar inverter, and how does it work?

Before we go any further, let's first break down what a solar inverter is. A solar inverter is a device that converts the electricity produced by a photovoltaic array into electricity that can be used in our homes. This allows solar energy to be seamlessly integrated into our existing power grid and used to power our appliances and devices. But why do PV modules generate energy that is different from what we actually use?

Solar panels generate direct current (DC) electricity - a type of electrical current that flows in one direction. This is because of the way that the photovoltaic cells within the modules are constructed. These cells are made with semiconductor materials, such as silicon, that absorb photons of light and convert them into electrical energy. When a photon strikes a cell, it excites electrons within the semiconductor material, causing them to be knocked loose from their parent atoms. These free electrons then move through the material, creating a flow of electrical current. This flow is unidirectional, which is why it is called direct.

Aside from photovoltaic systems, DC electricity is used in various applications, including powering batteries in devices like cellphones and laptops, as well as in electric vehicles and industrial equipment.

But most home appliances use alternating current (AC) because it is a safer and more efficient form of electricity. AC power is generated at power plants and then distributed to homes and businesses through the network of transmission and distribution lines. This type of power flows in a cyclical pattern, constantly reversing direction and changing voltage levels. This allows for a smooth and consistent flow of electricity, which is necessary for powering appliances like refrigerators, air conditioners, and washing machines.

Therefore, for clean power to be usable in our homes, we must convert it from DC to AC, and this is where the inverter comes into play.

DC circuit's electrical charge moves in one direction, creating a linear graph when plotted over time. On the other hand, the voltage and current in an AC circuit fluctuate, producing a sine wave pattern. By utilizing electronic components referred to as IGBTs, inverters break down DC power into pulses and form them into a sine wave shape. This process is known as Pulse Width Modulation (PWM).

Classification of solar inverters by grid connection

Solar inverters can be classified based on whether they are connected to the electrical grid. This includes types such as on-grid and off-grid. Let's explore how they differ and when they are used.

Grid-tied solar inverters

Grid-tied inverters are specially made for use in solar power systems that connect directly to the electric grid. These systems use panels and an inverter but don't have batteries. The grid-tie inverter ensures that the power from the panels is used to power a home first before any excess is sent back to the grid.

Grid-tied system is generally more budget-friendly because it does not require batteries or additional equipment. With net metering, the electricity generated by your solar system can offset the electricity you use from the grid during the night or on cloudy days. The grid also serves as a reliable storage solution for the energy you produce. However, if the grid goes down, the system will shut off as a safety precaution for utility workers. This means you will not have power during a blackout, and your setup will only turn back on when the power is restored. Additionally, you won’t be entirely independent from the grid.

Off-grid solar inverters

An off-grid inverter, also known as a battery inverter, is used in off-grid solar systems and operates independently from the main power grid. It works by converting DC power from batteries into AC power, which can then be used to power appliances. This inverter type is designed to handle loads that exceed its capacity rating and is typically used in properties that are not connected to the main power grid.

The benefits of using off-grid systems include being completely self-sufficient and being able to install them in remote areas where connecting to the main power grid is not an option. However, there are also some drawbacks to consider, such as the higher installation price and the need to charge batteries constantly.

Hybrid solar inverters

This inverter type combines the functions of a grid-tied solar inverter and an off-grid inverter into one unit, allowing it to manage power from your modules, batteries, and the grid at the same time. It can take the DC electricity produced by solar panels and convert it into AC electricity to power your home. It can also take AC electricity from the grid and store it in batteries for later use by converting it back into DC electricity.

A hybrid solar system can save you money on your electricity bills by letting you rely less on power from the grid. This is because this system includes both panels and battery storage, which helps you use more of the energy the modules generate. Keep in mind, though, that installing a hybrid system can be more expensive due to the added complexity.

Solar inverter types by technology

Solar inverters can also be categorized into string inverters, micro inverters, and string inverters with power optimizers. Below, we will take a closer look at each of these inverters types, examining their pros and cons and how they work.

String inverters

The first type we are going to discuss is a string inverter, also known as a central inverter. These devices are called string inverters because they are used in systems where multiple solar modules are connected in series, or "strings," to a single inverter.

For many years, string inverters have been the go-to choice for residential and commercial systems because of how simple and inexpensive they are to make and because they can handle various input voltages. Additionally, they have relatively high efficiency, with an average of 96-98%.

String inverters are known for their simple maintenance and troubleshooting process. Since they are usually placed in a central location, it's easy to access and fix any problems that may arise. This is especially useful in areas with extreme temperatures. String inverters also have the advantage of reduced wiring issues, as the connections between solar panels and an inverter are fewer. And finally, this technology tends to be cheaper than other alternatives.

However, a significant disadvantage when using string inverters is that if one solar panel in a string is shaded or fails, the entire string's output is affected, which can significantly decrease overall system performance. To address this issue, newer technologies like micro inverters and optimizers have been developed.

Micro inverters

Micro inverters are a relatively new technology in the solar market. They differ from traditional inverters in that they are attached to each individual panel rather than being centralized for an entire array.

One of the main advantages of micro inverters is that they allow for greater flexibility in the design and installation. Because each solar unit has its own inverter, it means that if one panel is not functioning correctly or is underperforming, it will not affect the overall performance of the system. This is in contrast to traditional central inverters, where a problem with one module can have a negative impact on the entire system.

Additionally, micro inverters offer greater energy yield as each panel can be optimized to perform at its maximum efficiency, regardless of how other panels perform. This can result in a higher overall energy yield from the photovoltaic system.

However, micro inverters also have some drawbacks. For one, they tend to cost more than traditional central inverters. This is because each panel requires its own micro inverter, which can add to the overall cost. Additionally, micro inverters are much more vulnerable to damage from weather and other environmental factors.

Power optimizers

Power optimizers are similar to micro inverters in that they are placed on or integrated with each solar panel, but they still send the power to a separate string inverter. These devices are considered a hybrid solution between a typical string inverter and micro inverters.

Power optimizers offer many benefits for solar systems, including increased power output. This is because they can make up for any performance losses that may happen due to shading, soiling, or temperature changes. By doing this, optimizers can make sure that each panel is functioning at its highest potential, resulting in a higher overall energy yield.

In addition to boosting performance, power optimizers also provide better tools for monitoring and resolving system problems. Since each solar panel is connected to a different power optimizer, it is simpler to identify and diagnose any issues that may occur. This can help to minimize downtime and enhance the overall performance and reliability of the solar system.

How much should you expect to pay?

Solar inverters price for a medium-sized setup can vary between $1000 and $1500. However, as the installation gets bigger, the inverter price can also go up. Generally, inverters cost around $0.28 per watt, with prices fluctuating between $0.50 to $0.10. They usually make up about 6% of the total installation price. For example, for a 6 kW installation, the inverter would be priced at around $1,100. If you opt for a model on the higher end of the price range, such as $0.50 per watt, it can increase the overall price by an additional $550.

Factors impacting the cost

If you're considering purchasing an inverter, it's important to understand the factors influencing the price. Let's explore them together.

Solar inverter type

The price of your photovoltaic system can vary significantly depending on the inverter type used. A string option can range in price from $1,000 to over $2,000, while micro inverters can tack on an extra $300 to the final bill.

Generally, when comparing the price of solar energy systems with micro inverters versus string inverters, it is estimated that a system with micro inverters will be around 20% more expensive. However, many homeowners find that the extra cost is worth it for the improved performance and efficiency.

As for power optimizers, they tend to have a lower price point than micro inverters, making them a cost efficient option for homeowners looking to improve their solar system’s performance without breaking the bank.

Grid connection is also an essential factor affecting the price. For example, an off-grid battery inverter will usually add $2,000 to $3,000 to the overall installation cost.

Power rating

The power rating of an inverter is another element that affects its price. This rating refers to the maximum amount of power the inverter can handle. The higher the power rating, the more expensive the inverter will be because a more powerful device requires more advanced technology and materials to operate effectively.

It is important to match the power rating of an inverter to the solar system’s size. If the inverter is not powerful enough to handle the amount of power generated by the panels, it will not be able to convert all of the power, and the system will not be efficient. This can lead to wasted energy and a higher price for the system. On the other hand, if the inverter is too powerful, it will be an unnecessary expense.

Quality and efficiency

The price of an inverter is greatly affected by its quality and efficiency. High-quality inverters, made with durable materials and built to withstand harsh weather, often come with advanced features such as monitoring and tracking systems for optimal performance and energy production. These types of inverters tend to be much more expensive.

Efficiency also plays a significant role in determining the solar panels inverter cost. Inverters with high-efficiency ratings can convert more energy from solar modules into usable electricity, allowing for more power production with fewer panels and ultimately leading to more considerable savings in the long run. However, these high-efficiency inverters are usually priced higher. When choosing an inverter for a solar system, it's essential to consider the long-term financial benefits.

Brand and reputation

The price of solar inverters is heavily influenced by the brand and reputation of the manufacturer. Consumers are often willing to pay a premium for products from reputable and well-established companies, as they perceive them to offer higher quality and more reliable products. This holds especially true for inverters, as they play a vital role in any photovoltaic system and must endure harsh outdoor conditions and operate dependably for an extended time.

Reputable brands also tend to have much better distribution networks and customer support systems in place, which can also contribute to their higher prices. Additionally, well-established brands often invest heavily in research and development to stay ahead of the competition, leading to higher prices for their products. Overall, while brand and reputation may contribute to higher prices for solar inverters, many consumers are willing to pay extra for the peace of mind that comes with purchasing a high-quality and reliable product from a trustworthy brand.

Final thoughts: finding a suitable model for your solar panel system

A solar inverter is an essential component of any photovoltaic system, as it converts the direct current electricity generated by the photovoltaic modules into alternating current electricity that can be used in homes and businesses. Solar inverter prices vary widely, depending on the type, size, and brand. You can find basic inverters for a budget-friendly price of one thousand dollars, but more advanced models can come with a higher price tag of four thousand dollars or more.

When shopping for an inverter, it is crucial to remember that the lowest price isn't always the best decision. Cheaper inverters may be less efficient, have shorter warranties, or be less reliable. It is important to research and compare different options to find an optimal inverter that is both high-quality and reasonably priced. It is also important to consult a professional to ensure that the inverter is compatible with your photovoltaic system and meets your specific needs.