AC Elwa 2 is a 0 - 3.5 kW linearly controlled water heater device for grid-connected photovoltaic systems and the successor to the proven AC ELWA-E. To maximize the self-consumption of your current PV system, AC Elwa 2 uses excess photovoltaic energy to heat your water. The increasing autonomy also protects against unpredictable or rising operating costs. With linear control, the PV feed-in power can be regulated to zero.