Solar + Battery + EV + Heat Pump: The Integrated Home, Costed
Four all-electric homes, twelve months of data. Solar, battery, EV and heat pump genuinely do multiply each other’s value — and 40% of the integrated installs we audited are misconfigured in ways that quietly cost €200–€400 a year.
The promise of sector coupling is arithmetic: your solar feeds the house, the surplus charges the battery, the battery covers the evening, the EV drinks the cheap night hours, and the heat pump pre-heats the boiler at solar noon. Every device makes every other device more valuable. The audits say the promise is real — when one brain coordinates it. The same audits say that brain is missing in two installations out of five.
The misconfigurations we found most: the battery’s AI dispatch and the heat pump’s schedule bidding against each other at the same cheap hour, spiking the capacity peak they were both meant to shave; the EV charger unaware of the battery, draining it at 32A while the house went dark; and the solar forecast ignored because nobody connected the weather feed. Each fix was a settings page, not new hardware.
The numbers from the best-performing home: 5.4 kWp solar, 10 kWh battery, one EV, one heat pump, dynamic contract, coordinated energy management. Annual grid import fell 61% against the unintegrated baseline. The capacity peak dropped from 4.4 to 2.3 kW. Total annual saving versus the same hardware unmanaged: €410. The hardware was mid-range; the orchestration was the premium component.
The buying implication inverts the usual advice: do not buy the four systems from four vendors and hope. Either buy an ecosystem that integrates natively — the all-in-one towers now handle solar, battery, EV DC charging and heat-pump interfaces in one unit — or insist on an open EMS layer and put the integration responsibility in the contract, named and priced. “They all work together” said at a kitchen table is worth nothing; written into the commissioning sheet, it is worth €400 a year.
Where to start if you own pieces already: check for a shared platform first (many battery apps can already see chargers and heat pumps), enable the solar-forecast feature, and schedule the heat pump’s hot-water cycle to solar noon. Those three settings captured most of the gap in our worst-performing home.
Method: four households, full-year energy audits, quarter-hour data across all circuits. The 40% misconfiguration figure comes from our installer-interview sample, not a census.