The manufacturer of solar-electric home technology My PV has further developed its solution for hot water with photovoltaic surplus. Whereas the previous heater could take up to three kilowatts of solar power, the new Elwa-E is infinitely variable up to 3.5 kilowatts. Because the unit can also control an external standard heating rod with 3 kilowatts, outputs of up to 6.5 kilowatts can be realised in total. This means that the solar power can be temporarily stored at different levels in a stratified storage system and that storage utilisation can be improved, says Gerhard Rimpler, Managing Director of My PV, describing the advantage of this feature of the new heating rod.

LAN or Wi-Fi - it's up to the circumstances

The new AC Elwa-E also has a Wi-Fi interface. It is true that a cable is always safer for communication between the inverter or energy management system and the heating rod, as Markus Gundendorfer, sales manager of My PV, points out. Nevertheless, the wireless transmission of control signals has the advantage that cables no longer have to be laid at great expense.

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A prerequisite, of course, is that the radio link between energy management, inverter and Elwa is not disturbed by thick reinforced concrete walls. For such cases, My PV has retained a cable connection for the new Elwa-E as well. The advantage of the LAN and Wi-Fi interface is that the Elwa can communicate with various energy management systems and inverters and is also suitable for the Smart Home.

Trade separation implemented

The biggest difference between the new AC Elwa 2 and its predecessor is that it is delivered in two parts that can be installed independently of each other. The heating element is still separated from the electronic unit on delivery. "This makes it possible to implement trade separation," Markus Gundendorfer explains. Because now the plumber can first install the actual heating element already in the buffer tank and then close the entire heating circuit. Only then does the electrician install the electronic unit and connect it - completely independently of the time of the plumbing installation. Time delays are thus avoided.

Dislay for commissioning and control

Another new feature of the improved Elwa-E is that it now has a display. This is already known from AC Thor from My PV. The Elwa can be commissioned and controlled via this display. My PV deliberately opted for a display - in contrast to control via an app on a smartphone or tablet, as this is more intuitive and direct to operate.

Compatible with storage units

The new AC Elwa 2 is also compatible with battery systems. If a battery storage system is integrated in the building, it is supplied with surplus solar power as a priority. Only when the battery is full does the AC Elwa 2 take over the storage of the solar power that is not used by other consumers, and uses it to heat the hot water or buffer storage tank. This is because water is the more cost-effective form of storage, which complements chemical storage batteries perfectly. In this way, more energy is used by the household itself, the load on the electricity grid is relieved and self-sufficiency is increased.

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The new heating rod will be available in March or April 2023 at the same price as the previous AC Elwa, My PV announces. (su/mfo)