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Inverters for commercial photovoltaic projects – insights into Krannich’s product line of inverters

Inverters for commercial photovoltaic projects – insights into Krannich’s product line of inverters

The correct selection of PV inverters for commercial photovoltaic projects or larger PV installations has a decisive influence on the long-term financial returns of PV systems. Although inverters account for less than 10% of system costs, they control 100% of system production and influence system costs by up to 20%. By carefully selecting the right inverter, energy production can be increased, and life cycle costs reduced. However, technical performance, acquisition costs, installation effort and follow-up costs should be weighed and considered in advance.

Since we have expanded our product line of inverters, we would like to give you an overview of our inverters for commercial photovoltaic systems. Therefore, we have taken a closer look at the products and compared them in the following table. You will get more detailed information in the course of the article: Enjoy reading!

SolarEdge SE30k / SE33.3k

New to our product line are SolarEdge SE30k and SE 33.3k for the 400V low voltage grid. With the introduction of SolarEdge 30k / 33.3k SolarEdge launches the next generation of three-phase inverters for commercial PV installations. The new inverters are designed to combine the power needed for commercial installations with ease of installation. This makes the inverter the smallest and lightest in its class. Thanks to a higher DC oversizing of 150%, plant owners will benefit from higher energy production. The integrated type 2 DC overvoltage protection, as well as optional RS485 and type 2 AC overvoltage protection, provide improved protection during lightning events and can make the purchase of external equipment redundant.

Further advantages are:

  • Unique efficiency (98.3%) and longer strings
  • Quick and easy commissioning of the inverter directly from a smartphone with SolarEdge SetApp
  • Integrated monitoring at module level for complete system transparency with Ethernet, WLAN or mobile communication
  • Extended safety function - integrated arc detection and optional quick shutdown (RSD)
  • IP65 - outdoor and indoor installation
  • Optional integrated DC safety unit - no additional external DC disconnector required
  • Ready for SolarEdge Energy Storage Solution
Three-phase inverter SolarEdge SE30k / SolarEdge SE33.3k


KOSTAL has added the PIKO CI to its range of inverters for commercial systems. The new commercial inverter PIKO CI is tailored to the requirements of commercial PV systems, large rooftop systems and open space systems. Thanks to its three performance classes of 30, 50 and 60 kW, it offers a wide range of possible applications for plant construction in projects. Thanks to the integrated KOSTAL Smart AC Switch, external coupling switches are no longer required and additional costs are saved. At the same time, the new project inverters offer increased safety and efficiency.

Furthermore, the special advantages include:

  • Up to 4 MPP trackers (PIKO CI 30: 2 MPP trackers)
  • 6 DC inputs for PIKO CI 30, 10 DC inputs for PIKO CI 50 and 12 DC inputs for PIKO CI 60
  • Wide MPP working voltage range of 180 - 950 V for PIKO CI 30, 200 - 960 V for PIKO CI 50 and PIKO CI 60
  • Flexible generator design through overcrowding of up to 50% (DC to AC)
  • Optimized generator design through system voltage of up to 1100 V
  • Maximum energy yield thanks to >98% efficiency
  • Feed management and communication integrated as standard, compatibility with many park controllers and data loggers
Kostal PIKO CI

SMA CORE2 Sunny Tripower

With the new Sunny Tripower CORE2, SMA is expanding its range of string inverters. The Sunny Tripower CORE1 is now followed by the Sunny Tripower SMA CORE2 offering more possibilities, more integration and more power.
The CORE1 has a capacity of 50 kW, 6 MPP trackers and 12 strings. As the world's first free-standing inverter, no complex installations are required.
In comparison: The Sunny Tripower CORE2 from SMA convinces with a flexible system design for larger commercial photovoltaic systems. The Sunny Tripower CORE2 is suitable for roof systems as well as for larger open spaces, thus the ideal inverter for decentralized plant structures up to the megawatt range. With 110 kilowatt output, 24 strings as well as 12 MPP trackers, the Sunny Tripower CORE2 always achieves a particularly high solar coverage ratio during the course of the day under various conditions, such as different roof inclinations and in open space systems.
The integrated software solution SMA ShadeFix ensures that the plant performance is automatically optimized at all times. This guarantees the highest possible yield even with partially shaded modules. Thanks to the automatic monitoring service SMA Smart Connected and the earliest possible fault detection the maximum yields of the PV system are additionally increased. Thus, the Sunny Tripower CORE2, as the central unit of the SMA Energy System Business, offers installers and plant operators high-quality and high-value components from a single source as well as future-proof expansion possibilities around the SMA storage solutions.

Your advantages at a glance:

  • Suitable for large roof systems and open spaces up to the MW range
  • 12 MPP trackers and 24 strings with 1100 VDC Sunclix connectors
  • Fast commissioning without additional DC-Combiner
  • Peak efficiency of 98.6%
  • Highest yields thanks to integrated software solution SMA ShadeFix
  • High IT security
Sunny Tripower CORE2

Sungrow SG33CX/SG40CX/SG50CX and SG110CX

As the leading manufacturer of inverters worldwide, Sungrow is launching a new class of multi-MPPT string inverters for 1000 Vdc systems in the project inverter sector with the models SG33CX/SG40CX/SG50CX and SG110CX. The inverters are the perfect choice for medium and large installations, as they are often used in commercial or agricultural applications.

The models SG33CX/SG40CX/SG50CX convince with up to 5 MPPTs and a maximum efficiency of 98.7%. The SG110CX model has 9 MPPTs and a maximum efficiency of 98.7%. The SG33CX/SG40CX/SG50CX models are compatible with glass-glass modules, whereas SG110CX is compatible with bifacial modules. You can see further advantages in the following:

Highly profitable

  • Up to 5 MPPTs with max. efficiency 98.7%
  • Compatible with bifacial module
  • Built-in PID regeneration function

Proven safety

  • Protection class IP66 and C5
  • Overvoltage protection type II for DC and AC
  • Compliant with global safety, EMC and power connection guidelines
Sungrow SG33CX/SG40CX/SG50CX and SG110CX

Huawei Sun2000-33KTL / 36KTL / 60KTL /100KTL

Huawei's 3-phase inverters are manufactured with the most modern components and offer many product advantages. They do not require external fans and are specially designed for commercial rooftop or open space installations. The Huawei Sun2000-33KTL / 36KTL / 60KTL series offers you the following advantages:

  • 4 - 6 MPP trackers
  • Intelligent string monitoring
  • Max. efficiency 98,6%
  • Fuse free design
  • Type II arrester for DC & AC

The Huawei Sun2000-100KTL offers the following additional benefits:

  • 10 MPP tracker
  • 98.8% (at 480 V) Max. efficiency
  • String Level Management
  • Smart UI characteristic curve diagnosis
  • MBUS Supported
  • Surge arrester for DC & AC
  • Protection class IP66
Huawei Sun2000-33KTL / 36KTL / 60KTL / 100KTL

Delta RPI M30A / M50A / M88H

Delta offers in its product range different highly efficient three-phase solar inverters for the European market. In the following, we would like to present you to the Delta inverters for commercial photovoltaic systems that we have rated best. They are the perfect choice for large solar systems, as they are often used in commercial or agricultural applications.

Delta RPI M30A und Delta RPI M50A

As part of the expansion of its product line for large commercial plants, Delta introduced its compact transformerless three-phase inverter RPI M30A. It delivers a nominal apparent power of 30 kVA, but reaches a maximum apparent power of up to 33 kVA. Compared to other 30 kVA competing inverters, the RPI M30A delivers 10% more power and yield. It achieves a peak efficiency of 98.5%. The wide input voltage range of 200 - 1000 V and the control with 2 MPP trackers supporting balanced and unbalanced loads (33/67% or 67/33%) give you maximum flexibility in system design. This ensures maximum yield even for large commercial installations on roofs facing in different directions. Further advantages are:

  • Aluminium housing for long-lasting protection against moisture and corrosion
  • Suitable for indoor and outdoor use (IP65)

With the Delta RPI M50A we introduce a three-phase transformerless inverter with 50 kVA, which offers one of the highest output power of the Delta product series and is therefore an ideal choice for commercial project installations. The inverter achieves a very high efficiency of 98.6% and an outstanding ratio between energy density and size. Thanks to the wide input voltage range of 200 - 1100 V and the 2 MPP trackers, you get maximum flexibility in system design and maximum yield. Thanks to the integrated and replaceable string fuses and the AC/DC-side Type II surge arrester, further simplification of the installation process and additional savings are achieved. Additional advantages result from:

  • Aluminum housing for long-lasting protection against moisture and corrosion
  • Suitable for indoor and outdoor use (IP65)
  • Compact design with exceptional power density for easy installation
Delta RPI M30A and Delta RPI M50A

Delta M88H

The M88H inverter is an economically attractive solution for commercial installations and is available in two versions, with standard MC4 plug connections or screw terminals. The output power can be additionally increased by connecting the 480V grid.

  • Output power: 73 kVA at 400 Vac, 88kVA at 480 Vac
  • M88H CF model:
    • 18 x MC4 strings on 2 MPPT
    • String fuses
    • DC disconnector
    • Overvoltage protection type II
  • M88H ST model:
    • Screw terminals 35-150mm²
    • Overvoltage protection type II
    • External monitoring, e.g. Solarlog
Delta Strangwechselrichter M88H

Fimer/ABB PVS-50-TL / PVS-100-TL

PVS-50-TL is the cloud-networked three-phase string solution from Fimer/ABB (ABB is now Fimer) that enables cost-effective large and distributed photovoltaic systems for both commercial and utility applications. This new addition to the PVS family of string inverters with three independent MPPTs and a rated output of up to 60 kW helps maximize the return on investment in large systems. It offers all the advantages of a decentralized configuration for both ground-level and roof installations:

  • Horizontal and vertical installation
  • Easy access to the terminal box thanks to hinges and cam locks on the cover
  • Power module and junction box in one compact housing
  • Wi-Fi interface for commissioning and configuration
  • Reactive Power Management
  • Remote monitoring and firmware upgrade via the AuroraCloud platform (without logger)
  • Up to 30°C ambient temperature, 10% higher rated power
  • Can be operated at up to 4000 meters
  • Dynamic feed-in control

The PVS-100/120-TL is a new three-phase string inverter from Fimer/ABB with cloud connection. It is the right solution for cost-efficient decentralized photovoltaic systems, both for open spaces and for large commercial rooftop applications. With power outputs of up to 120 kW and 6 independent MPPT, the powerful string inverter maximizes the profitability of the PV system. The highlights for you are:

  • Inverter without transformer
  • 120 kW for 480 V AC and 100 kW for 400 V AC 
  • Configuration by default via Wi-Fi
  • Two Ethernet interfaces for plant communication
  • Extensive set of specific network standards that can be selected directly on site 
  • Two-level topology for wide entrance area 
  • Both vertical and horizontal installation
  • Separate connection box for quick exchange
  • IP66 Protection class
  • Maximum efficiency up to 98,9%
Fimer/ABB PVS-50-TL / PVS-100-TL

Costs ct/watt and inverter capacity

PV systems for commercial enterprises and large-scale photovoltaic inverters benefit from economies of scale and the associated reduction in costs per ct/watt of inverter output. The following chart provides you a rough comparison of the cost per ct/watt and maximum AC power of the inverters of SolarEdge*, KOSTAL, SMA and Delta in comparison:


*Due to the different topology and the basic use of optimizers, SolarEdge can only be compared to other manufacturers' inverters to a limited extent. The SolarEdge calculations shown in the graph are based on a sample calculation using a P801 375Wp optimizer.

NA-protection in comparison

In addition to price, other factors play an important role in ensuring a good return on investment in the long term. Additional costs arise, for example, from the legally required mains and system protection, during installation, regular maintenance and as follow-up costs in the event of utilization errors and plant defects. It is therefore necessary to consider total costs and utility when choosing an inverter. For this reason, we would like to provide you with some information on the factors mentioned above.

Pursuant to VDE AR-N 4105 for systems above 30 kVA a central mains and system protection (NA-protection) is required. This consists of two main components: the network monitor, which monitors the voltage and frequency of the power network, and the disconnection point, which performs the physical disconnection in the event of a fault. For a long time, this disconnection point consisted of two contactors connected in series. According to the current standard, these have been replaced by a single, motor-driven clutch switch. Which functions a mains and system protection fulfills in detail, you can read in our blog post "Information on how NA protection works".

Fact is: This switch must be able to disconnect the entire power of all connected inverters and is therefore cost-intensive (usual cost range is about 1.000-1.800€ depending on the size of the plant).

To reduce these additional costs, some inverter manufacturers had the AC grid relays already integrated in the devices certified for external control by a mains and system protection monitor. In this way investment costs can be significantly reduced. In addition to the use of standardized mains and systems protection monitors, the individual device connection must of course also be taken into account.

The SMA CORE1 inverters and all PIKO CI from KOSTAL, for example, feature this function. The SolarEdge SE30k and SE33.3k inverters can also use the integrated grid relays in the inverter as mains and system protection. The use of AC relay control is supported starting with inverter firmware (FW) version 3.18xx (and higher). Of course, this also applies to the current SE 55k / SE82.8k and its successors SE66.6k and SE100k.

Conclusion for your choice of an inverter for commercial installations

Especially for large commercial facilities, the choice of the right inverter should be decided individually based on the requirements and existing conditions. It is also important to keep an eye on possible synergy effects. These already begin with the equipment of the inverter, the interfaces, for example for direct marketing, through to the cost-efficient control of the grid relays in the inverter by a mains and system protection monitor.

For an overview of the most important key data, please use our table at the beginning of the article. Our diagram in the middle will help you with the price indication. However, possible additional components have not yet been included here. The basic use of optimizers results in a sensitive cost-benefit ratio.

Would you like to get more information about inverters for commercial plants? In our last blog post on the topic of inverters for commercial plants we already gave you a summary of our most important manufacturers.

Do you need support in the realization of large projects? Our project team will be happy to support you either throughout all project phases - from development, technical planning and implementation to the operation of the plant - or only in certain sub-sections.

04.11.2020 12:00
by your Krannich Team

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