Everything You Need To Know About Solar Inverters
When picturing a solar energy system, most people think of solar panels. But there are various other components that can be included in a solar power system, such as solar meters, inverters, racking, and more. In this article, we’ll spotlight the solar inverter.
Solar inverters are an essential component of solar systems. They’re responsible for converting power generated by the sun into practical energy we can use in our homes. Keep reading to learn more about what a solar inverter is, how it works, the different types of solar inverters available in 2024, and how to choose a suitable solar inverter for your system.
What is a solar inverter?
A solar inverter is one of the most crucial components of a solar power system, converting the direct current (DC) energy generated by solar panels into the alternating current (AC) electricity required by household appliances. This process ensures the energy generated by solar panels can be used in your home.
Solar inverters come in various types, including string inverters, microinverters, and hybrid inverters, each suited to different applications. We’ll look at each of these solar inverter types in more detail below.
How do solar inverters work?
Solar inverters work by converting the direct current (DC) electricity generated by solar panels into alternating 120V/240V current (AC) electricity that can be used by household appliances and fed into the electrical grid. Here’s how the process works:
- Step 1: DC power is generated: Solar photovoltaic (PV) panels are exposed to sunlight and generate DC energy. Depending on your system, the DC energy can either be stored in a battery for later use or fed into the solar inverter.
- Step 2: DC power is converted: Electronic components inside the inverter, like transistors and capacitors, convert the DC power into AC power. This is done by switching the DC input at high frequencies to produce a pulsed DC signal that’s then smoothed into a clean AC output.
Different types of solar inverters
There are three main types of solar inverters used in 2024: string inverters, microinverters, and hybrid inverters. Each of these inverters work differently and are suitable for different applications.
String inverter
Also known as a central inverter, a string inverter is the most common type of solar inverter for residential use. Each solar installation will typically need one string inverter. These inverters connect multiple solar panels, known as a string, to one centrally located inverter that converts the entire string from DC electricity to AC power. They essentially transform energy in bulk amounts.
String inverters are the most cost-effective option. Because they’re usually installed in an accessible location (i.e. the side of your home) they can be easier to service when needed. That said, if one panel in the string malfunctions or is in the shade, it affects the performance of all the panels. For that reason, if your roof is partially shaded throughout the day then a microinverter may be more suitable for your home.
If you already have string inverters installed and want to prevent dips in performance when panels are shaded or damaged, you can pair them with a DC power optimizer. Like microinverters, these are installed individually on solar panels but are much more affordable. With power optimizers, other solar panels won’t be as affected if one panel’s energy production dips.
Microinverters
Microinverters are small inverters attached to each individual solar panel, converting DC power to AC at the panel level. The main benefit of microinverters is that they improve efficiency by preventing one panel’s issues from affecting the whole system. This can provide more solar energy, especially in shady conditions. If one solar panel is in the shade, another panel in full sun can continue generating power at maximum efficiency.
Microinverters, such as the Enphase IQ8, are the ideal choice for partially shaded or complex roof layouts where panels face different directions or are set at different angles. Because they’re connected to each panel, they can be more expensive and complicated to install. That said, microinverters generally come with stronger, 25-year warranties compared to string inverters, which are usually around 12 years.
Hybrid inverter
Also known as multi-mode inverters, hybrid inverters are designed to work with solar energy systems that incorporate battery storage. These inverters convert DC energy to AC energy and direct excess power to batteries. Hybrid inverters provide flexibility for both on- and off-grid systems, efficiently produce energy after dark, and come in compact designs that are suitable for limited spaces.
Pros & cons of different inverter types
To help you compare the difference between each type of solar inverter, we outline what each solar inverter is suitable for and their pros and cons.
String inverters
String inverters are suitable for small-scale residential and commercial solar arrays with uniform sunlight exposure. They’re ideal for systems where all panels face the same direction and there is minimal shading. Some newer string inverters will allow multiple strings per inverter and thus allowing multiple directions and splitting the effect of shade.
Pros of string inverters include:
- Cost-effective: String inverters are the least expensive inverter option.
- Simple to install: Installation and wiring of string inverters is simple as there is just one inverter to be installed in a single location.
- Easy maintenance & troubleshooting: Solar inverters have fewer components that can break, and since all elements are in one location, maintenance and troubleshooting is easy. They’re also easier to access when servicing is required.
- Option to improve performance: DC power optimizers can be installed to improve the performance of string inverters.
Cons of string inverters include:
- Affected performance: If one panel is damaged or in the shade, all solar panel performance is affected. This is because energy is sent to string inverters in bulk. If one panel stops or slows production, performance of the entire system dips to generate the maximum power of the weakest panel.
- Less flexible: String inverters are less suitable for solar systems with varying panel orientations or part shading.
- Excess heat: String inverters generate a lot of heat due to the amount of power they handle. To prevent overheating and keep the system running smoothly, it is recommended they are installed in the shade
- Weaker warranties: Warranties for string inverters are usually around 12 years, which is significantly less than microinverters which offer around 25 years.
Microinverter
Microinverters are best suited for systems with complex roofs, shading issues, or solar energy systems where panels face different directions. They’re also convenient for those who plan to enlarge their systems in the future.
Pros of microinverters include:
- Improved efficiency: With microinverters, DC power is immediately converted to AC at each individual solar panel. If performance of one solar panel is reduced or affected, the other panels and microinverters will continue to generate their maximum output, improving the overall efficiency of a solar panel system.
- Longer lasting: Because microinverters are small, they don’t generate too much heat and don’t require the same amount of cooling as string inverters. This also makes them longer-lasting.
- Stronger warranties: Microinverter warranties are generally offered for 25 years, compared to the typical 12-year warranties of string inverters.
Cons of microinverters include:
- More expensive: Microinverters have a higher initial cost compared to string inverters. Because each panel requires its own inverter, you will need to purchase several units.
- More complex installation & maintenance: Installation of microinverters can be more complicated than string inverters. There are more components involved and the parts are located on the roof, unlike string inverters. This also makes maintenance, troubleshooting, and repairs more difficult and therefore costlier.
Hybrid inverter
Hybrid inverters are designed to work with battery storage. They’re the most suitable option for homes and businesses looking to maximize self-consumption and backup power.
Pros of hybrid inverters include:
- Off-grid capabilities: Hybrid inverters integrate with battery storage to provide greater energy independence, including backup power during grid outages.
- Energy monitoring: With hybrid inverters, it’s easy to monitor both your solar power system and battery storage from a single interface. This allows you to track your energy expenditure and optimize usage for maximum efficiency.
Cons of hybrid inverters include:
- More costly: Hybrid inverters are more expensive than standard string or microinverters.
- Complex installation: They can be more complex to install and configure compared to string inverters. Careful planning and design is required to optimize their performance.
- Limited future options: Unlike string inverters, which can be improved with power optimizers, or microinverters, which can easily be scaled, hybrid inverters have limited flexibility when it comes to future upgrades.
How to choose a solar inverter
Choosing the most suitable solar inverter for your needs requires considering your system's setup and potential shading issues. The best way to do this is by consulting with an expert solar team. A professional solar panel installer can assess your goals and requirements and help you choose an inverter that balances cost with efficiency.
To help you with your decision, we’ve outlined some things to consider when choosing a solar inverter below.
Type of system
The type of solar system you have, whether it’s grid-tied, off-grid, or hybrid, dictates the kind of inverter you need.
- Grid-tied: These systems send DC power directly from solar panels to inverters that convert the current into AC power. This energy can then be used or sent back to the power grid.
- Off-grid & hybrid: These systems send DC power from photovoltaic modules to a solar charge controller, which then sends the power to a solar battery or inverter depending on your specifications.
Some setups may require multiple solar inverters and storage inverters.
Type of inverter
As discussed above, there are three main types of inverter. The table below makes it easy to compare between each of these inverter types and choose the most suitable one for your needs.
STRING INVERTERS |
MICROINVERTERS |
HYBRID INVERTERS |
|
DESCRIPTION |
Converts DC to AC from a series (string) of solar panels. |
Converts DC to AC at each individual solar panel. |
Converts DC to AC and manages battery storage and grid connection. |
BEST FOR |
Uniform sunlight exposure and simple roof designs. |
Complex roofs with shading issues or varied panel orientations. |
Systems incorporating energy storage. |
EFFICIENCY |
Can be affected if one panel is shaded or damaged. |
Each panel operates independently for maximum efficiency. |
Good efficiency with energy management capabilities. |
COST |
Lower initial cost. |
Higher initial cost. |
Higher initial cost due to battery integration. |
INSTALLATION COMPLEXITY |
Simple with fewer components. |
More complex as it requires installation at each panel. |
More complex as it integrates with batteries and grid. |
MAINTENANCE |
Simple as there is one single inverter. |
More complex as there are more components. |
More complex but provides advanced monitoring & control. |
IMPACT OF SHADE |
Significant & affects the whole string of solar panels. |
Minimal, only the shaded panel is affected. |
Minimal due to backup battery storage. |
SCALABILITY |
Limited by string design. |
Highly scalable & panels can be easily added. |
Highly scalable & more panels can be added. |
WARRANTY |
Typically 12 years. |
Typically 20-25 years. |
Typically 10-15 years. |
Efficiency
When it comes to solar inverters, efficiency measures how much energy is lost (generally through heat) while the inverter is working. You can read efficiency ratings when comparing different solar inverters on the market. A higher efficiency rating means less energy is lost during conversion, which maximizes the power output of your solar panels. It’s especially important to consider efficiency when choosing a solar inverter for larger systems, as even small efficiency gains can add up to significant energy savings over time.
Compatibility
When choosing a solar inverter, be sure it’s compatible with your photovoltaic modules and has a higher rated power input than the maximum electricity production potential of your solar panel array. At the same time, make sure the inverter is compatible with other balance of system components and your utility provider.
Durability & warranty
Inverters need to withstand various environmental conditions, from heat to humidity and dust. Choose a solar inverter with features like effective heat dissipation, weatherproofing, and durable construction materials to ensure it works reliably into the future.
One way to check durability is by evaluating the length of a warranty period. This can give a good indication of how confident a manufacturer is in their product. String inverters generally come with a 10-12 year warranty, while microinverter warranties can be twice as long. For peace of mind, and to protect your investment against potential issues, look for a product with a generous warranty period.
Budget
As with anything, budget is an important consideration when choosing the right solar inverter for your energy system. This doesn’t mean choosing the cheapest option, but weighing up the various costs that may be involved, including:
- Cost of installation & maintenance
- Efficiency and output
- Long-term value
- Government incentives and financing options.
Summary: Everything you need to know about solar inverters
With the right solar inverter, your solar energy system will reliably work at maximum efficiency so you can get the most out of your investment. By now, you should have a solid understanding of the different solar inverter types available and which is most suitable for your specific location, purposes, and goals. If you’re still unsure, the team at Sun Valley Solar will be happy to help.
As Arizona's leading solar energy company, we're your trusted partner for residential and commercial solar energy solutions. Reach out to our friendly team on 480-576-5693 or fill in our contact form to receive a free, no-obligation solar consultation for further guidance on solar inverters and starting your solar project.