Autarco presents the new Apex R6 mounting system

The Apex R6 mounting system

Autarco introduces the improved Apex R6 mounting system. This system is available for roof mounting of solar panels with an adjustable roof hook for pitched roofs, a wave clip for corrugated iron roofs and pole bolts with L-hook. Clear advantages of the Apex R6 are the easily adjustable rails that can be adjusted from top to bottom and from right to left and the fact that no loose nuts and bolts need to be used during assembly. Thanks to the smart and stable construction of the R6, ultra-fast mounting is possible while the solar panels are optimally and safely supported.

The R6 mounting system is available from the beginning of June 2022 and is part of the complete total solution from Autarco.

The Apex R6 mounting system

The Apex R6 mounting system from Autarco offers ultimate flexibility and ease of installation thanks to adjustable rails, ‘sliding’ clamps that are reusable up to 10 times and a center clamp with potential equalization. Furthermore, a PV installer no longer needs to use loose bolts or nuts during installation.

Other important features of this system are:

  • 40mm reach to adjust rail height;
  • Easy to apply black stylish end cap;
  • Bolts have a TORX-30 head;
  • All fixings are provided with a “rail connector”

Developed together with PV installers

In order to create the most efficient system possible, we have extensively tested the R6 months together with a number of experienced PV installers. We have used the feedback we received after these test installations to further optimize the system and to develop one of the most user-friendly mounting systems for solar panels.

Requests for further information about this press release can be sent to

Read more about the Apex R6 here

Calculating the cable connection of an inverter to the electricity grid

Solar panels generate energy that is fed back into the grid. To ensure that this can happen, the inverter will always make the voltage a little higher than the connection to the grid so that the power goes into the grid. To make sure that the voltage does not get too high, it is important to use the right cables. There is a maximum voltage to prevent other connected devices from breaking down (in the Netherlands this is 253 Volt)..

Maximum voltage difference in a cable

A common value for the maximum voltage difference in a cable is 1%. With 230 volts, we therefore recommend that there should be no more than 2.3 volts difference. If this loss increases, the cable will become warmer and one must ensure that it is adequately cooled. If a cable cannot dissipate its heat, a fire or short-circuiting may occur.

In addition to selecting the correct value for the fuses and circuit breakers, it is therefore important to check that all the cables are suitable for feeding back the power before installation.

Calculation example of voltage drop with a 1000 watt inverter

At maximum power and a voltage of 230 V, the inverter delivers a current of:
1000 W/230 V = 4.34 A.
A cable with a length of 43 metres and 2.5 mm2 is connected.
The resistance of a wire in the cable is:
R = 0.0175 x 43 /2.5 = 0.3 ohms, total (for both wires) therefore 0.6 ohms.
The voltage drop in the cable is then:
V = I x R = 4.34 A x 0.6 ohm = 2.6 Volt

So the loss is: 2.6 V /230 V = 1.1%.
In this case, a 1000 W inverter can be connected with a maximum cable length of 43 metres and the voltage loss is acceptable at around 1%. If you want to reduce the loss in the cable, you must connect a thicker cable, e.g. 4 mm2.

Maximum length of a cable

The following table calculates the maximum cable length for a number of inverters (assuming a voltage drop of around 1%).

wdt_ID Dikte (mm2) 1 kW 3 kW 5 kW 5 kW (3 fasen) 6 kW (3 fasen)
1 2,50 43 15 7
2 4,00 69 24 12 53 43
3 6,00 105 36 18 80 65
4 10,00 171 57 28

It is clear from the example of the 5 kW inverter that a three-phase inverter is more favourable when an electrical system is already equipped with three phases.

All calculations above are intended as a guide. If, for example, the mains voltage supplied in a system is higher, it may be advisable to choose a thicker cable or to adapt the system.

You can always contact Autarco for advice and suggestions, if you are going to install a larger inverter in an existing installation. This can prevent high costs afterwards.

New Helios feature: Direct shade visualization

Optimizing a system design can be a tedious task, taking much of your time. With our most recent addition to Helios, that belongs to the past. With our new direct shade visualization, feedback on your system design is now only one click away! No need to wait for the yield calculations to finish, see the effect of your design choices instantly.

An important part of designing a well performing PV system is dealing with shade on the solar panels. Of course you want to have as little shading as possible, but in most designs this can’t be omitted fully. Therefore it’s important to know how shading is affecting the solar panels, so you can adjust your design to the situation. Direct shade visualization allows you to investigate and mitigate shading effects on the modules in your design, to make sure you end up with the most efficient solution for your customer.

When shade is visualized in Helios, all solar panels will show a colour to indicate their shade losses due to obstacles in the direct environment. With this information you can easily see which solar panels are not effective and choose to delete them. It will also help you to create your string plan in such a way that shaded solar panels are combined as much as possible.

You can select the shade visualisation feature by clicking on the symbol below the “calculate azimuth feature”

Yet another step in making solar simple and helping our dealers to offer the best PV-system design to their customers.

Want to know more about out best-in-class design software Helios? You can sign up for a free Helios demo account by clicking on this link or contact us via

Internal PELD

PELD stands for Power Export Limiter device and limits the power output to a specified level. Autarco already provides a separately sold PELD which is mainly used for larger  PV-systems with multiple inverters.

For smaller systems with one inverter the Internal PEL feature can be used on our newest Mark-II inverters. This can be done with a separately sold energy meter (S2.1P-SMARTMETER.1 for 1-phase grade tied connections, S2.3P-SMARTMETER.1 for 3-phase grid tied connections) which is easily connected to the inverter. Once connected to the inverter, the internal PEL feature ensure grid exports are constantly measured and will not exceed the set value. A PELD can specifically be used to improve the business case of your customers in the following two cases.

  1. When power output needs to be limited because the internal AC device or grid can not handle a higher power out.
  2. When the grid operator (temporarily) demands that  no or limited energy may be supplied to the grid.

Click here to learn more about our newest Mark-II inverters

Autarco drone met infrarood camera Video

Drone inspecties maken het mogelijk om heel snel, grote aantallen zonnepanelen te inspecteren en doelgericht eventuele problemen te verhelpen.

Met onder andere infrarood cameras helpen drones om heel gericht issues zoals degradatie en string-storingen op te sporen en daarna op te lossen.

In onderstaande video zijn wij samen met Dutch Drone Company het dak opgegaan bij Nexus Corporation in Vianen om in levende lijve een drone inspectie te zien.


What is a digital twin?

The added value of our 'Digital Twin'

There is so much marketing jargon these days that it’s hard for us to use the term Digitized or “Digital Twin” without feeling like we’re trying to impress with hollow terms. That is why we have decided to explain a term often used by Autarco such as ‘Digital Twin’ in layman terms.

The added value of Autarco’s ‘Digital Twin’ is that it allows us to actively measure the weather-dependent performance of the system at 15-minute intervals. This accurate performance analysis allows us to verify whether installations are performing as expected. If this is not the case, we can respond quickly to problems through timely detection. The end result is an average performance improvement of 8% for residential PV systems and a 5% improvement for commercial systems.

What is the "Digital Twin"

The ‘Digital Twin’ is an exact digital replica of your physical system. It is created in our software, Helios, during the design phase of your project. It forms the basis for the system that will be installed on your roof, the yield we expect the system to have for the kWh guarantee and ultimately the price that the installer asks you to pay.

The ‘Digital Twin’ is designed on top of an elevation map that the designer can adjust to add or remove obstacles. Shade is modeled not only from a chimney on your roof, but also from the tree or hill behind your house.

How do we use the 'Digital Twin'?

Autarco uses the ‘Digital Twin’ to:

  • Verify that the installation is made according to the design and that it is correctly positioned. We can achieve a high level of trust through our remote verification, but we also rely on working with the best network of dealers who maintain high quality standards.
  • Detect defects or abnormalities that occur during the life of the system.

In short: the solar power system on your roof must match the calculation of the “Digital Twin” in terms of yield. If this doesn’t happen, something is often wrong.

Simple explanation in layman terms

We are now going to simplify some technical details of the ‘Digital Twin’ using children’s toys.

A solar power system consists of a number of “strings”, which are solar panels that are connected to each other in groups. They usually consist of six to 20 panels, depending on the system size.

In Autarco’s digitized inverters, each string is monitored individually and provides detailed information to our European cloud every five to fifteen minutes.

The information in these messages (voltage, current, power) creates a “shape” that constantly changes based on the actual system design, different shade levels, environmental conditions and possible product defects. You can compare each string in the monitoring message with a 3D block (see image below).

At the same time, the “Digital Twin” creates an expectation of the “shape” of each string. To do this, we use data that we receive from different satellites (irradiance, cloud cover and temperature) that we receive every 15 minutes to represent reality as well as possible. We can usually match this satellite data to less than 1 km from your actual location across Europe. Think of the expectation generated by the digital twin as the holes in the ball.

The monitoring messages are the 3D shapes that must fit into the holes. There is a hole and a shape for each ‘string’. If one of the shapes doesn’t fit in the cube, something is wrong and Helios automatically creates a notification in the system. We then check the system for defects.

Who else can do this?

No one.

Autarco is currently the only solar company worldwide that uses this technology.

How does Autarco calculate the expected yield?

How soon can you expect a return on your investment?

Renewable energy generated from natural sources such as wind and sun is a hot topic in the Netherlands. After all, we all have to become more sustainable in order to achieve the set climate objectives. The government stimulates this process with, among other things, subsidies and a netting scheme. This ensures that more and more houses, business premises, schools and factory roofs are equipped with solar panels. In short, the solar energy sector is thriving. However, individuals and companies do not place solar panels on the roof purely for idealistic reasons. The initial investment in a solar power system must be recouped. Preferably as soon as possible!

How is an expected return calculated?

The installer’s quote states an expected return on an annual basis and an estimated payback period. There are several models to calculate this with different levels of accuracy. At its core, however, the expected return is based on:

  • Historical weather data
  • The slope and azimuth of the roof
  • Shadow analysis

The historical weather data usually looks at data from the past 15 to 30 years and calculates an average from that. Add all these different factors together and it becomes quite a complicated calculation. Just because of the high degree of shade and a wide variety of roofs, there is often a considerable margin of error in this estimate.

The expected yield of your system is based on this long-term average, but due to annual variation in sunlight and temperature around this average, this can go up to +/-15%.

Very large projects typically make two types of yield estimates that take into account this variation in irradiance and other factors:

P50: The expected yield that will be achieved half the time

P90: The expected yield with 90% confidence.

Analysis of 20% of all utility projects in the US by kWh Analytics* shows that P90 production events, thus failing to achieve the stated efficiency, are actually three times more common than the P90 definition implies. The impact of these performance events on P90 is that the realized return is half lower than originally estimated.

Monitoring of current weather data is essential

While these P50 and P90 forecasts are useful for financial modeling prior to project construction, any reliable performance indicator needs to be adjusted to the weather once installed.

As you can see in the graph above, the Netherlands has had a higher irradiance in recent years compared to the historical average. Therefore, it is likely that underperformance of a solar power system will remain undiscovered. The system can achieve the expected yield stated in the quotation, but if it was an extremely sunny year, the system could even underperform by up to 15%.

At Autarco, we allow for some natural variation in modeling and data accuracy, and define any system that performs less than 95% of its weather-adjusted forecast as substandard.

Within the industry, weather-adjusted performance is measured through a metric called the “Energy Performance Index” (EPI). The EPI is also defined as the actual weather-corrected forecast of a solar power system.

This is where Autarco’s ‘Digital Twin’ and our data management skills make the difference. With other design software, the ‘digital copy’ is removed once the final quote and installation plans are generated. Our ‘Digital Twin’ remains active. We use this to verify the correct installation of the system and then to base the system’s performance on current weather data that we receive every 15 minutes for every square kilometer in Europe.

A monitoring portal only shows if a system is producing power, but does not provide a relevant benchmark for performance. That’s why Autarco’s kWh guarantee and weather-dependent performance monitoring are so important.

Autarco makes changes to its kWh guarantee

Systems with a kWh guarantee and active performance monitoring perform significantly better

Autarco is the only Dutch brand of solar power systems with an insured kWh guarantee. The value of this yield guarantee and the associated service and maintenance that is provided is enormous. Research into the performance of 5000 PV systems has shown that Autarco systems with a kWh guarantee perform three times better than comparable systems without.

Because we see an increase in the demand for revenue and PR (performance ratio) guarantees and operations and maintenance services, a number of things will change as of June 17, 2021.

Costs per kilowatt hour reduced

The free yield guarantee for the first five years after installation disappears. Instead, Autarco introduces two different kWh guarantees:

  • A Standard kWh guarantee insured by Autarco
  • A Premium kWh guarantee insured by the kWh guarantee fund foundation and Lloyd’s of London

Since the free kWh warranty for the first five years will disappear, the costs will increase slightly. However, this is more than offset by a reduction in the costs of yield guarantees for a period of ten or fifteen years. These are sometimes more than half cheaper.

Extra income for dealers through the sale of the kWh guarantee

Autarco dealers can generate extra income with the sale of the kWh guarantee. Autarco pays a commission for each kWh guarantee sold. There is also a chance of a performance bonus. This allows our dealers to benefit from recurring revenues and increase their net margin by up to 40%.

Operations and maintenance contract mandatory

For systems larger than 30 kWp, it is mandatory to conclude a service and maintenance contract. An Autarco dealer can choose to offer a service and maintenance contract themselves or have Autarco manage the service and maintenance.

Higher guaranteed return

We noticed that when the sun is low in the sky, we estimate the production of the solar panels too high. On an annual basis, our indication was correct. To make our calculations even more accurate, we’ve introduced things like angle reflection and an improved model for shading between the rows. This makes it possible to calculate the expected yield of a solar power system even more accurately than before. That is why we can now issue a higher yield guarantee.

P.R. Guarantees

Autarco will now also issue fully insured Performance Ratio (PR) guarantees to customers based on current satellite data. PR guarantees will only be issued for PV systems larger than 30 kWp.

Generate additional income by selling the Autarco kWh guarantee

How to monetize the kWh guarantee?

Autarco dealers can now generate additional income from the sale of the kWh guarantee starting the 17th of June 2021. For each kWh guarantee sold, Autarco pays a commission of 10% of the total amount to the dealer. There is also a chance of a performance bonus if the installed systems generate high yields. This allows our dealers to benefit from recurring revenue and increase their net margin by up to 40%.

Additional income

Autarco dealers can extend the customer lifecycle with the sale of the kWh guarantee and operations and maintenance packages (O&M). For projects larger than 30 kilowatts, the purchase of a service and maintenance package in combination with a kWh guarantee is mandatory. In this way we guarantee safe solar power systems that perform well.

Various constructions are possible in which:

  • Autarco issues the kWh guarantee to the end customer and Autarco provides full service and maintenance.
  • Autarco issues the kWh guarantee to the end customer and provides the dealer with service and maintenance.
  • Autarco issues the kWh guarantee to the end-customer and no O&M contract is required (only for systems less than 30 kilowatts!)

Depending on the sold construction (kWh warranty and Service & Maintenance), the dealer receives at least a commission of 10% of the total sales amount. This commission is paid annually or once every five years. There is also a performance bonus for dealers with systems that deliver between 100 and 115% of the estimated return.

For instance:

A 250 kW Autarco system with 15 years of standard service and maintenance and a 15-year premium guarantee (0.10/kWh) can generate a total of € 6,000 in recurring revenues (0.024/Wp).


If a dealer installs three Megawatts of Autarco solar panels per year with 15 years of standard service and maintenance plus a 15-year standard guarantee (0.10/kWh), this can generate a total of € 27,000 in revenue. If the systems perform above average, the dealer will also receive a performance bonus of € 9000.

If the same dealer sells the Premium kWh warranty instead of the standard kWh warranty, the commission will increase to 36,000 over a period of 15 years.

“By selling the Autarco kWh guarantee and O&M packages our dealers can increase their net margin up to 40%”

Dan Horan, CEO Autarco

A standard and premium guarantee

Autarco offers customers the option to choose from two different kWh guarantees:

  • A standard kWh guarantee insured by Autarco on a portfolio level
  • A premium kWh guarantee insured individually by the kWh guarantee fund foundation and Lloyd’s of London

Insuring the yield of a solar power system is possible from € 0.10 per kWh with a standard kWh guarantee.

About Autarco

Autarco is the only producer to supply a solar energy system in which all components are developed in-house and therefore connect seamlessly. Thanks to this total solution, Autarco can also offer the kWh guarantee, with which you are guaranteed to save on your energy bill in the long term.

The performance of your Autarco system is insured through the independent Stichting kWh-guarantee fund in collaboration with the world’s largest insurer Lloyd’s Of London. Is the system underperforming? Then the difference is simply paid out in cash per kilowatt hour missed.

45% of solar systems underperforms

Systems with an insured kWh guarantee and active performance monitoring perform three times better.

An analysis of nearly three thousand bankable residential roof systems in the Netherlands, looking at performance data up to 8 years ago, shows that only 55% of the systems without a kWh guarantee achieve the expected yield. On the other hand, systems with a kWh guarantee provide better performance. 85% of the systems with a kWh guarantee perform as expected or even exceed expectations. Of course, a kWh guarantee does not in itself improve the performance of a system, but the processes and software that make this guarantee possible do.

Design and system checks

After the design and installation of a residential solar power system, the majority of solar installers in the Netherlands spend hardly any energy on O&M. Whether your solar panels actually deliver the estimated yield and are installed correctly remains uncertain.

Larger PV systems of over 5 Megawatt (more than 10.000 panels) are better maintained and monitored, however, for example, an analysis of 20% of all utility projects in the US by kWh Analytics* shows that P90 production events, i.e. not achieving the stated efficiency, are actually three times more common than the P90 definition implies. The impact of these performance events on P90 is that the realized return can be up to half of what was originally estimated.

Unnecessary loss of yield

The outcome of Autarco’s study shows that, even when using high quality products, in many cases this loss of efficiency can be prevented with good maintenance, supporting software and accurate use of (historical) weather data. After all, based on this, we are able to  issue our high insured kWh guarantee.

What sets Autarco apart

During the design phase of a solar power system, Autarco makes a ‘Digital Twin’, or a digital copy, of the physical system design. Before we issue a kWh guarantee, every new system is verified against this Digital Twin. For example, we check the installation plan and the complete installation of the inverter and solar panels. This ensures that the system is installed safely and according to the correct specifications.

Even after installation and issuance of the kWh guarantee, Autarco continues to monitor each system. If a solar power system performs less than 95% of what it should deliver according to the ‘Digital Twin’, we will contact the installer so that he can check the installation again and solve any problems. Autarco only provides this aftercare for solar power systems with a kWh guarantee.

Weather-corrected forecast

The Netherlands has had a higher irradiance in recent years compared to the historical average. Therefore, it is more likely that underperformance of a solar power system will remain undiscovered. The system can achieve the expected yield stated in the quotation, but if it was an extremely sunny year, the system could still underperform by up to 15%.

At Autarco, we allow for some natural variation in modeling and data accuracy, and define any system that performs less than 95% of its weather-adjusted forecast as under-performing


Autarco bases its conclusion on data from 2679 solar power systems, of which 1638 have a kWh guarantee and 1041 do not. The systems without a kWh guarantee have not received a professional check after installation. These systems also lack corrected performance monitoring based on current weather data. The investigated solar power systems consist of Tier-1 quality solar panels and inverters.

These systems are using identical hardware with a common set of installers. The only material difference is whether the system has received the special care and attention that Autarco gives to systems with a performance guarantee.

Our findings are also supported by an expanded 2020 Energy Validation Study completed by DNV GL, a leading energy consultant and engineering firm, that demonstrate that the median performance of commercial projects  below 50kW is only 94.6%.