Powerwall 3 adds heat pump optimization to bank solar as hot water
Tesla launched Heat Pump Optimization for Powerwall 3 and 3P, storing surplus solar or cheap grid power as heat — widening what the energy business can do for a home (Europe only for now).
Per Electrek, the Powerwall sends a compatible heat pump either a "normal" or "boost" signal, so it heats water beyond immediate need when solar is in surplus or power is cheap. It is Europe-only; Tesla has not said whether it will come to the US or Canada.
In Self-Powered mode it boosts only when solar remains after household loads; in Savings mode it boosts when solar is available or grid power is cheapest, based on 24-hour tariff forecasts. It uses Germany's BWP SG-Ready standard and requires Powerwall 3/3P firmware 26.26+, an SG-Ready-certified heat pump, wiring by a Tesla-certified installer and Tesla app 4.59.1+.
Signals are recommendations the heat pump's thermostat can override, and the system reverts to normal during an outage so backup loads come first. Electrek says a 300-liter tank heated an extra 30°C stores about 10.5 kWh of heat for roughly 3.5 kWh of electricity at a COP of 3. Germany sold 299,000 heating heat pumps in 2025, up 55% year over year (BWP).
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