Quality and safety are non-negotiable for us because in the end exactly these factors guarantee maximum and sustainable efficiency of PV projects. To live up to this claim, we continuously put our products and those of other manufacturers through their paces in our certified test centers.

You will find key findings at a glance below.

1. Passive cooling actively burns money

Passive cooling reduces the inverter’s power output and PV component’s lifetime by up to 75%.

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For more information on cooling see our website Too passive cooling.

 
 

2. Power loss at sunshine

Inexpensive inverters often lose their power output at an ambient temperature of 21°C—they can’t handle the sun.

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You’ll fine more information on this subject here Power loss at sunshine.

 
 

3. Poor DC:AC ratios increase costs and decrease profitability

Our competitors advises a low DC:AC ratio of 1:1. This forces system operators to use up to 40% more inverters per PV system.

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For more details on DC:AC ratios see Poor DC:AC ratio.

 
 

4. Electromagnetic interferences could get you into severe legal trouble

Some inexpensive inverters produce electromagnetic interferences, which disturb, among others, the radio frequences of air traffic control or railroad communications—PV system operators will have to deal with legal consequences.

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Visit Illegal EMI built in for more information.

 
 

5. Server out of control

Chinese laws make it mandatory for Chinese companies to operate cloud services in China—this might easily cause a safety problem.

The great firewall and how it works

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For more information on server reliability see Server out of control.

 
 

Conclusion

Our Test results reveal that using a relatively inexpensive inverter might come at a price PV system operators probably would not want to pay. SMA demands highest quality standards of its products. That is why our experts at the SMA test center simulate the entire life of an inverter in fast motion and put our products through their paces in certified laboratories.

Find a short video of our test center here:

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Learn more

Here, you can find a summary of all test results at one page and for download

4.50 avg. rating (90% score) - 4 votes

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Everyone who operates a PV system with SMA inverters should register their system in Sunny Portal.

Additionally, customers who have an inverter with the SMA Smart Connected convenience package, such as Sunny Boy 3.0 – 5.0, have to activate the SMA Smart Connected in Sunny Portal as part of the package. Once activated, PV system operators can start reaping the benefits of the convenience package.

This video shows how to register and activate a PV system in Sunny Portal.

For more tech tip videos, for example on installing a Sunny Boy 3.0 – 5.0, visit our YouTube channel. 

4.00 avg. rating (86% score) - 1 vote

In the future, SMA will equip all devices with WLAN and Ethernet communication–so called IP communication–by replacing the previous Bluetooth communication. Thus PV systems are extremely easy to integrate into existing home networks with an internet connection. Below we have provided information for you, including how you benefit.

1. What are the benefits of WLAN and Ethernet communication?

  • Easy PV system monitoring thanks to integrated Webconnect function
    The integrated Speedwire/Webconnect interface in all SMA inverters up to 12 kW is able to establish a link with Sunny Portal and Sunny Places via the PV system operator’s router. The PV system can thus go online without any additional costs for a data logger.
  • Use of standard components
    Optimization of PV system communication will make it possible to use standard components from electronics retail outlets (e.g., WLAN repeaters, WLAN/DLAN access points, WLAN wireless sockets, etc.). Not only will this help PV system operators save on system costs, but they can also extend their home network with components, such as a repeater.
  • Flexible use thanks to Modbus as a third-party interface
    With the factory-installed open Modbus TCP interface, data loggers from other providers can also be flexibly integrated. This allows operators to save even more money because an additional communication interface (e.g., RS485) is no longer necessary to connect to SMA systems.

2. What has to be considered when planning a PV system?

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System setup without data logger for PV systems with SMA inverters up to 12 kW

  • The Sunny Boy 1.5/2.5 and 3.0/5.0 inverters are connected to the router using the integrated Webconnect interface via WLAN or Ethernet cable, which means that they are integrated into PV system monitoring.
  • In the future, the Sunny Boy 3.0/5.0TL-21 and Sunny Tripower XY-20 models will have an Ethernet interface only and must therefore be connected to the router with wires.
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System setup with the Sunny Home Manager 2.0 for PV systems with intelligent energy management

The Sunny Home Manager 2.0 is connected to the router via the Ethernet cable. Compatible loads and WLAN SMA radio-controlled sockets can be integrated into the system using the router. Further information on Sunny Home Manager 2.0 can be found here.

3. How can I identify SMA inverters with Ethernet communication?

The Sunny Boy TL-21 and Sunny Tripower TL-20 inverters will no longer have Bluetooth communication capability. However, they will still be fitted with Ethernet communication.

These devices are easily identifiable by the “ETHERNET ONLY” written on both the inverter and box, and by the yellow label on the inverters, which ensures rapid identification and smooth processes.

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0.00 avg. rating (0% score) - 0 votes

The more self-generated solar energy you use in your own home, the more efficient your PV system becomes. When self-consumption is high, grid feed-in goes down. If you combine a battery-storage system with an electric heating element, you can use as much of your solar power as possible for yourself. Thanks to electric water heating, our colleague Manuel März enjoys hot water essentially at zero cost, which means that his heat pump even gets some time off in the summer month.

For März, installing a PV system with a storage system in spring 2014 was the first step toward independence from rising electricity costs and his electric utility company. He is an expert in solar energy and has spent 10 years at SMA, where his responsibilities include off-grid electricity supply solutions. This includes energy self-sufficient mountain cabins and power supply systems for remote islands. The focus is always on generating energy precisely where it is needed.

He consistently pursues this goal in his personal life as well. Since spring 2015, he and his wife Rebecca have been realizing his dream of using electricity produced entirely from solar power. In addition to the PV system and heat pump, their energy supply is now equipped with two AC ELWA-E heating elements from my-PV. These help reduce electricity procurement costs and minimize the heating and hot water bill. The heating elements work like an immersion heater, efficiently converting the excess solar power from the hot water and heating tanks into heat in a continuous, grid-compatible process.

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242.05 KWh + 12.18 KWh was not fed into the utility grid, but was used at home instead.

Generating hot water electrically and saving costs

Heating and hot water appliances account for as much as 75% of a household’s energy needs. In Germany, the average daily consumption of drinking water is roughly 120 liters. Approximately a third of this is heated and generally referred to as hot water. On average, a typical home in Germany consumes 22 cubic meters of hot water per year at a cost of around €300. The cost of heating water varies considerably by the cubic meter and depending on the fuel used. However, if you heat your water with self-generated solar power instead, the costs are effectively zero.

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The self-consumption quota is 99%. Otherwise, the energy from the AC-ELWA-E 006/008 would have entered the utility grid at €0.13 per KWh.

The März family chose an east–west arrangement for their PV system, which means that it can be used to generate solar power from sunrise to sunset. This type of arrangement is currently very popular because people are now looking to maximize self-consumption rather than simply yield the best possible feed-in tariff with a south-facing configuration. This is precisely the purpose of a heating element that uses surplus solar energy from the PV system to heat water. Since 2016, the couple have been partially heating their water using the AC ELWA-E with solar power from the 10 kilowatt peak system in an old building that they renovated themselves. Initial concerns that the water would not be available quickly enough or in sufficient quantities proved to be unfounded. The elements are controlled by the Sunny Home Manager, which intelligently manages the household and automatically activates the heating elements, always at the right power level, when excess solar power is available. Self-consumption is optimized every single day of the year in this order:

1. Supplying home appliances: major domestic appliances such as washing machines and dishwashers can be programmed to run on solar power.

2. Charging the battery: the battery provides solar energy for evening and night hours. Regular charge and discharge cycles extend the battery’s service life.

3. Activating the my-PV ELWA_006 heating element (summer) and generating hot water: the AC ELWA-E is activated when there is surplus energy and heats water for cooking, showering and washing hands.

4. Activating the my-PV ELWA_008 heating element (winter only) and generating hot water: the AC ELWA-E is supplied via solar energy and heats the water used to heat the house.

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Intelligent energy management enables 96% of the energy generated to be used in the home. Last March, purchased electricity was reduced by 62% (self-sufficiency quota).

Protecting the heat pump and extending its service life

Although the ELWA has the lowest priority in the März household, it enables the air to water heat pump to be switched off entirely in the summer months. This extends the service life of the equipment—after all, if it’s not running, it can’t break down. The heating element itself is largely maintenance-free. Depending on the mineral content of the water, it may be advisable to use a filter cartridge to prevent the formation of limescale. This is because limescale, which forms deposits similar to those found in kettles, has an insulating effect and can hinder energy exchange by the heating element.

Cat Mohrchen also enjoys the cozy warmth of the hot-water ceiling heating.

Cat Mohrchen also enjoys the cozy warmth of the hot-water ceiling heating.

The renovated old building offers another special feature, which is that the house is heated using hot-water ceiling heating. This exceptionally energy-saving method of operation ideally complements the heat pump and enables a low flow temperature of 35°C, even in an old building. Mohrchen the cat is not the only one to enjoy the agreeable radiant heat—friends and relatives are also frequently pleasantly surprised. Another positive side effect of the space heating system is that there is no need for unsightly radiators, and dust bunnies are a thing of the past thanks to the absence of circulated air.

Incidentally, März doesn’t buy into the claim that the heat pump requires a longer start-up time and thus more energy to heat up when it is switched on again. Protecting the pump is his top priority. If a little more energy than usual is indeed needed, he doesn’t think it too much of a problem—after all, the energy comes from the PV system and doesn’t cost anything.

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100% independence

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The water heater AC ELWA-E, rubber duck included 😉

Profile: the “solar heating system”

To boost self-consumption of their own solar power, the März family, from the town of Borken, added the my-PV AC ELWA-E heating element to their grid-connected storage system in spring 2016. The resulting hybrid storage system enables the self-generated solar power to be utilized in full. Only when all appliances have been supplied, the battery charged and the water electrically heated does the März family feed solar power into the utility grid.

The AC ELWA-E elements are incorporated via Ethernet into intelligent energy management with the Sunny Home Manager. They are infinitely variable from zero to three kilowatts and adjust their output every second

to the supply of electricity, and consume only 1.5 watts in standby mode.

The Sunny Home Manager manages the flow of energy such that self-consumption is covered first, then the battery is charged; the remaining solar power is used to heat the building and provide hot water. The buffer tank collects solar power from the roof in the form of thermal energy.

PV system: 10 kWp east–west arrangement, 62° roof pitch

Inverter: SMA Sunny Tripower STP8000TL-20, 3 x Sunny Island 4.4M-11 battery inverters

Battery: Exide SH48V16.0-B
Sealed lead-acid batteries with up to 3800 cycles at 50% DOD (depth of discharge)
Total capacity 330 Ah (equates to 16 KWh). Usable capacity: approximately 8 kWh

Controller: Sunny Home Manager, SMA Energy Meter, SMA Sunny Sensor Box

Heater: air to water heat pump for drinking and hot water; each drinking and hot water storage tank is fitted with an electric heater

Water heater: AC ELWA-E

3.33 avg. rating (73% score) - 3 votes