Sermatec & Soluna Combo

Sungrow|LG|Trina Solar

Generating electricity from renewable sources is becoming very popular nowadays. The impact of the pandemic and of the energy crisis makes us think about how to maintain and improve our current energy comfort. Such improvement could be achieving at least partial energy self-sufficiency and independence from an external supplier of electricity. Find out how to do it and how much you can save if you make the transition.

Unless you live in the Wuthering Heights or in an old mill, then the only acceptable renewable alternative for you, out of all of them, will be solar energy. People are often under the impression that merely installing a few solar panels is enough and then you can unplug from the distribution grid with no worries. However, we don’t live in a climate with constant sunshine, and especially in winter, the photovoltaic system doesn’t deliver any energy. The solar energy production is very unpredictable even during the summer months (changes during the day and during the night).

But there is a solution. The surplus of unused energy must be stored properly. Besides solar panels, you also need a converter with a battery system.

Which converter should you choose?

In general, a converter is a device that changes the properties and parameters of an input signal into different properties of the output signal. The converter we need is called an inverter. Inverters convert direct electrical current from solar panels into alternating electrical current which has the same parameters that the conventional distribution grid has. Inverters differ in several important operating parameters and characteristics:

  • Off-grid/On-grid – the inverter allows island operation only (without connecting to the distribution grid), or the opposite, operates only when connected to the distribution grid.
  • Hybrid –** this type of inverter has two modes: with a connection to the distribution grid, and the so-called backup mode. A high-quality hybrid inverter then automatically controls which source it gets or converts electricity from: photovoltaic panels, batteries, or the distribution grid. The exchanger primarily draws electricity from its own resources.
  • Symmetric – the inverter supplies all 3 phases of the home distribution system equally, regardless of their current load. Therefore, in one phase, the electricity is taken from the grid and in a different phase, the photovoltaic power is not used.
  • Asymmetric – the inverter supplies power to each phase unevenly, which increases the efficiency of the system and its own consumption. Therefore, it uses the full potential of the installed photovoltaic panels.

To make the most out of your photovoltaic system and get the best savings, choose the hybrid asymmetric inverter with sufficient power.


How to determine the inverter power required? Firstly, calculate the average daily consumption of all your installed electrical appliances. For the average family of four, with energy saving appliances (class A+ a A++) and with energy saving lighting, we estimate the average daily consumption to be 5.5 kW/h. Multiply that number by the number of days of the required accumulation and divide that by the power of the converter, which should be nearing 100%.

We chose the SERMATEC SMT-10K-TL-TH inverter as the ideal one. It has an extraordinary maximum efficiency of 97,6%. The output power of the inverter is 10 kW, it can deliver up to 15 kW at peak, for a limited period of time). 10kW of power is also the limit for getting government subsidies, with this inverter, you can draw the subsidies with no worries.

High efficiency is not the only advantage of this inverter. In addition to its modern design, it also offers:

  • a quick switch to island mode (in less than 10 ms)
  • very low consumption
  • using full power in backup mode
  • Wi-Fi monitoring
  • it runs quietly (< 30 dB) – so can be installed anywhere, even outside of technical rooms
  • lifespan of 25 years at least
  • a 5-year guarantee with the possibility of an extension to 10 years.

The configuration is flexible, it adapts to the best suitable operating conditions, including the option of recharging from the grid. This is beneficial not only for solar systems, but also for people with multiple tariff subscriptions when it’s possible to charge the batteries to full capacity at a low tariff and then use the energy at a time of a high tariff.

The Soluna Battery

There are many ways to accumulate electricity (compressed air, supercapacitors, fuel cells etc.), however, none of those can be used in family houses. The easiest and currently most accessible solution are batteries. They significantly reduce grid overflows, which substantially improves the economics of operation of the entire photovoltaic system.

We chose the SOLUNA 12K lithium battery to be the ideal partner of the SERMATEC SMT-10K-TL-TH inverter. It has the capacity of almost 12 kWh, therefore in our intended system it could supply the household with energy for two whole days. When installing the battery, don’t forget to air out the room where you keep your accumulators and ensure sufficient ventilation air flow.

Sermatec & Soluna Combo

The three-phase hybrid inverter Sermatec ensures efficient conversion of direct current from solar panels to alternating current of standard voltage, which is used in households. But only when it’s connected to the modern lithium batteries Soluna, the user has completely different possibilities of use, in many ways.

This combo doesn’t only provide the conventional use of solar energy.  It ensures energy self-sufficiency in times of a distribution grid outage. Meaning that during an outage, the function of the device switches to the so-called island system, where the consumption is powered by the battery system.

It is a system with an asymmetric energy distribution, i.e., distribution according to the actual consumption in each phase. Economic payback of the whole setup is mainly limited by the use of energy – asymmetric mode is crucial for the economics of operation.

This system is suitable mainly for family houses. The users want to achieve not only economic and environmental savings at a time of soaring energy prices, but also want to be self-sufficient during a distribution grid outage. You can actually use up to 70% of the energy that is produced and during summer months you can save up to 95% by barely purchasing energy from the distribution grid.

Reach out to us today and the whole setup will be at your door in a few days. If you’re interested in a different exchanger and battery system setup, we are happy to discuss a custom configuration to fit your needs.