Mr Hauser, energy supply is a hot topic at the moment. Why should the focus be especially on energy efficiency when you want to increase your independence with a power storage system?

There are two reasons. Efficiency benefits the climate and your wallet. The more efficiently a battery stores solar power, the less energy is lost. It saves money every single day and actively supports climate protection. A seemingly small difference in efficiency will add up with great effect over time and reduce your electricity bills. It is similar to a dripping water tap. A few drops will quickly add up to many litres a month if you don't fix the tap.

Can we digest this as follows: the more efficient a power storage system is, the more sustainable and cost-effective it is?

Exactly. Two main items make a system especially efficient. First and foremost, low conversion and standby losses of the entire storage system are essential to achieve high energy efficiency. A fact that is also emphasised by HTW Berlin. Our system is highly effective with an average conversion efficiency in discharge mode of 97.6 per cent. Added to this are low standby losses. The other important item is a fast system response time. Our system needs just seven-tenths of a second to settle in. Here, you benefit from every watt of energy you can generate yourself and don't have to draw from the public grid.

Result of the HTW Berlin Energy Storage Inspection 2022

More and more people want to increase independence in their energy supply. Is that a reason you offer a back-up power function for your storage systems?

The pandemic has further boosted the demand for power storage systems. When we develop our systems, the focus is next to climate protection also, especially on our customers' requirements and needs. It is where the back-up power function comes into play. It is optional and provides even more independence. In case of a power failure, the storage system switches to back-up power within seconds. So you are not sitting in the dark and are not forced to light up the candles. Our storage system supplies lights, cookers, internet routers, television, refrigerator and other selected consumers with back-up power. The photovoltaic system continues to be operational and can also recharge the storage battery.

The RCT Power storage systems are grid-serving. What does that mean?

Grid bottlenecks present a big problem to the grid operators. Therefore, federal and state governments often make the subsidies for a solar power storage system dependent on its grid-serving capabilities. The forecast-based charging management systems of our solar power storage systems fulfil the grid-serving requirements. RCT Power storage systems reduce the load on the power grid and are thus contributing to the reduction of energy transition costs. It is a win-win situation for society and the environment.

RCT Power was again the test winner in 2022. Although, HTW Berlin already observed last year system performance improvements across the board. What did RCT Power do to stay on top?

Our advantage is that we develop and manufacture the complete storage system. RCT Power provides both the battery and the inverter. We can therefore offer a complete, perfectly coordinated and highly efficient system. It gives us a technological lead. One other essential factor behind the success is our team. It is experienced, highly motivated and has a passionate drive for innovation. It also believes in the crucial importance of solar energy to combat climate change.

The usable storage capacity for your systems is, according to the HTW's tests, 2 per cent higher than RCT Power's stated figures. How can that be? Are your measurements incorrect?

No, we measure our systems in a proper way. Or rather, we have them measured. The renowned AIT (Austrian Institute of Technology) in Vienna has conducted the system measurements following the official efficiency guidelines on our behalf. The institute has been performing tests and measurements on photovoltaics and power electronics for many years. At RCT Power, we place a lot of emphasis on protection against deep discharge. Compared to the sometimes exaggerated statements about system performance by our competitors we tend to stay on the conservative side. Honesty and trust are fundamental values for us.

The smaller storage system from RCT Power came in third in the 5 kWp category. Are you disappointed?

The answer is a yes and a no. Yes, because it was a tight race at the top. Our system was only 1.1 per cent behind the test winner and 0.1 per cent behind the two joint runners-up. That is a pity, of course. And no, in practical terms there is only a minimal difference. Our smaller storage system is with an SPI of 91.1 per cent also highly energy-efficient. It has been among the best-performing systems on the market in the 5 kW category for several years now.

Will RCT Power also participate in next year's energy storage inspection?

Definitely. The energy storage inspection results are a great confirmation of our development work. Last year we even set an absolute record in the 10 kW storage system category. Many of our competitors are backed by large corporations. RCT Power, on the other hand, is a medium-sized company that builds long-term customer relationships. We place great emphasis on personal customer service and our maxim is sustainable growth. We are not yet among the biggest, but we are among the best on the market.

Mr Hauser, thank you very much for this informative conversation.

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