A photovoltaic system is incomplete without a good inverter, as only then can the generated solar energy be converted into electricity. You can choose between string inverters, micro inverters or hybrid inverters for your PV system. Optimizers are a good option for solar panels that are partially located in the shade.
As a solar energy products distributor, we offer inverters from top brands like GoodWe, Growatt, Sungrow and Solis inverter. We are pleased to offer you a diverse product range so that you can provide your customers with the right solution for every project. If you want to learn more about the differences between inverter types, check out our blog: What are the different types of inverters?
A solar panel inverter is one of the most important components in a solar system. It converts the variable direct current (DC) output of photovoltaic (PV) solar panels into usable 240 V alternating current (AC) power suitable for use with electrical equipment.
The unused electricity generated is returned to the grid (power lines) or stored in local storage systems. For this purpose, a hybrid inverter with an integrated battery system can be used.
What are the different types of inverters?
There are different types of inverters for photovoltaic systems on the market. Selection of the correct inverter depends on the end use. An inverter converts the direct current (DC) generated by the solar panels into alternating current (AC). Alternating Current (AC) is electricity that you can use in your home or be sold to energy suppliers who send excess electricity to the grid.
There are various types of inverters available in the solar panel market. all these are:
- Centralized inverter, also known as string inverter
- Power optimizer
- Hybrid inverter
Microinverters and power optimizers are often collectively referred to as the MLPE (Module Level Power Electronics) group. String inverters are by far the most widely used inverter type worldwide. Due to the rapid development of technology, MLPE technology is rapidly gaining popularity and market share, and development costs have dropped significantly in recent years.
In addition to its function of converting DC power to AC power, a hybrid inverter also has a battery that can store the power produced.
What does an inverter do?
Inverters, together with solar panels, form the basis of a solar power system. The inverter ensures that energy is safely absorbed into the grid and, equally importantly, optimizes power generation under different conditions to produce the maximum amount of energy.
What is MPPT?
MPPT is the mechanism in the inverter to extract maximum power from the solar panels. The inverter does this by loading the solar panels at an optimal load rather than a maximum load.
Due to changing lighting conditions (light intensity), shadows and viewing angles, the power produced by solar panels is also constantly changing. Maximum Power Point Tracker (MPPT) is a mechanism that searches for the maximum power output point of a solar panel and extracts optimal power from the solar panel under different conditions.
Some inverters have multiple MPPT inputs. The advantage of having multiple MPPTs on the converter is that the output of each MPPT can be assigned independently. With multiple MPPTs, the inverter can receive input from a series of panels facing different directions, different distances, different output capacities, and even different types of panels.
What is a microinverter?
Microinverters are small inverters placed directly behind the panel. This enables end users to individually monitor the operation of the panels and, if a failure occurs, can be easily traced. Microinverters are widely used, especially in the consumer market. Microinverters are generally more expensive compared to string inverters and power optimizers.
The electricity generated by the panels is directly converted into AC power through a microinverter. Unlike many other configurations, power does not go to a "central" inverter. In some cases, microinverters are integrated into solar panels, but they are often retrofitted into solar panel mounting systems.
One of the biggest benefits of microinverters is that they can reduce the negative effects of shading. The conversion from DC to AC current occurs on each individual panel, so there is no power loss.
For string inverters, if a single panel fails completely due to a fault or defect, this will lead to the failure of the entire string in the PV installation. When using a microinverter, the remaining solar panels will still produce energy without being hindered by a failed panel.
How does a string inverter work?
Solar panels are connected in series. For example, when you place 12 solar panels, you can divide them into 2 series of 6 panels each. These "series" are also called "strings". Each string of solar panels is connected to a string inverter, which converts the DC power generated by the solar panels into AC power.
String inverters are a mature technology that has been used for decades, but they are not suitable for every configuration. Every solar configuration is only as efficient as its weakest link. This means that each string of solar panels produces the same power as the least efficient solar panel.
When part of the string board is in the shade for part of the day, this means the entire string is producing less power. This is why string inverters are not always the best choice.
How does the power optimizer work?
Just like microinverters, power optimizers are attached to each solar panel to optimize energy production. Instead of converting DC to AC, a power optimizer optimizes the DC generated, which is then converted by a "central" inverter.
In addition, the power optimizer continuously provides information about the solar panels so that any mismatch between panels in the string can be cleared faster. Install the optimizer quickly and easily with a single installation.
Which inverter is right for me?
When choosing an inverter for your PV project, there are several factors that determine the most appropriate type. The following questions and answers can help you choose the right inverter.
What kind of power converter?
The inverter must fit the total capacity of the solar panels. The capacity of a solar panel is expressed in units of WP (Watt Peak). This value tells you how much power the solar panel will produce under optimal conditions. Of course, reality isn't that perfect, so you need to make the switch. In the Netherlands, 1 Wp generates approximately 0.85 kWh per year. An average household consumes 3500kWh of electricity per year and requires about 4000Wp.
To shade or not to shade?
The question of whether the panels are in the shade (partly) or part of the day is very relevant to the choice of inverter. The power generated by solar panels is based on the weakest link in the series, in this case, the darkest panel. This can be overcome in two ways:
Choose a power optimizer or microinverter. They are placed behind each solar panel, and the output of each solar panel is individually optimized.
By making a string of individual solar panels while in shade. It is important to choose an inverter with multiple trackers that continuously check the power of the strings.
Which brand of inverter should I choose?
A few years ago, Chinese inverters were not the best choice. Today, the largest Asian brands can compete with Western brands. The arrival of the RoHS (2006) quality mark ensures quality standards and guarantees the safety of solar panel inverters.
Our range of inverters are sourced from top brands such as GoodWe, Growatt, Sungrow and Solis.
The functionality of the solar panels is always monitored via the inverter. This can be interpreted in different ways. Some inverters come with multiple connectivity options, such as Ethernet connectivity, WiFi, and Bluetooth. Not all inverters offer a standard solution for this, but the most common methods are:
Via WiFi: Many inverters have WiFi connectivity, some with both 2.4 and 5Ghz. However, WiFi connections require power. All important information is available at a glance, with the option to go deeper into certain data, such as production, consumption and possible storage. The inverter can be configured and read via smartphone, tablet or laptop.
Via Bluetooth: The inverter data can also be read via Bluetooth. However, this is not the best option since the connection is usually not very strong and discontinuous. Also, you cannot read the inverter from the internet.
Via Ethernet: Via Ethernet connection, you can connect the inverter to your router via a network cable. A connection is then established to the manufacturer's server. You can then view your solar panel's performance from anywhere via the app or website. This connection method is the most stable and recommended, but for some inverters this connection is optional and sometimes a separate module must be purchased.
Via USB: Some inverters have a USB connection. This way, the data can only be read on the inverter itself, which is less than ideal.
Via built-in web server (latest generation inverters): You can connect the inverter from your own wireless network and this information can then be read.
Zigbee: Zigbee creates a network within your wireless network through which you can not only read and configure the inverter, but also control other home automation devices.