Solar PV has been "smart" for a decade — inverters communicate with monitoring apps, batteries optimise charging based on tariff signals, and EV chargers divert surplus PV to vehicles. In 2026 the integration has reached a new level: open API access from the major inverter manufacturers makes solar PV a first-class citizen in any home-automation system. This article covers what's possible, what manufacturers support, and how to specify it on a new build.
What "smart" means in 2026 solar
Three layers of integration matter: (1) Monitoring — real-time visibility of generation, consumption and export; this has been mainstream since 2018. (2) Optimisation — automated charging of batteries during off-peak tariff windows and discharging during peak periods; mainstream since 2022. (3) Whole-home automation — solar generation triggering decisions across heating, EV charging, hot water and discretionary loads (dishwashers, washing machines, pool heaters); this is the 2025-26 capability that's newly mainstream.
Inverter API support
The four most-installed inverter brands in UK new builds all support open APIs in 2026: SolarEdge (REST API via solaredge.com), SunSynk (MQTT and REST), Enphase (Enlighten API), and GivEnergy (REST and MQTT). All four return real-time generation, consumption, battery state-of-charge and grid import/export data. The APIs are documented, free for owner use, and rate-limited at generous levels (typically 60+ requests/hour).
Home automation platforms
Three platforms dominate UK self-build home automation: (1) Loxone — a Linz-based system with strong UK installer network, native Modbus and MQTT support, used on many architect-led custom builds; (2) Home Assistant — open-source, runs on a Raspberry Pi or NUC, has community integrations for every major UK inverter brand; (3) Hubitat — local-first hub-based system, growing UK presence, native Z-Wave/Zigbee plus REST integrations. All three integrate with the major inverter APIs through standard plugins or with light bridging code.
Practical automations on a new build
Common automations we see specified on self-build FHS installations: (1) EV solar diversion — Zappi charger reads inverter generation and diverts surplus PV to the car, no grid import; (2) Battery tariff optimisation — battery charges from grid during 30p Octopus Agile cheap-rate windows, discharges during 70p+ peaks; (3) Hot water heat-up — immersion heater triggered when battery is full and surplus PV is being exported, providing free hot water; (4) Dishwasher / washing machine deferral — appliances wait for surplus PV (Miele and Bosch both support this through their respective APIs); (5) Pre-heating — ASHP runs at higher setpoint when PV is generating, banking heat for the evening.
What new-build wiring should include
For maximum smart-home flexibility post-completion, the new-build first-fix wiring should include: (1) Cat6 ethernet to the inverter location (not just WiFi — for API reliability); (2) Modbus RS485 cable run from inverter to the home-automation hub location; (3) Spare 16A circuit for a controllable immersion heater; (4) Smart-meter compatibility (most UK new-build smart meters now support consumer access devices for direct half-hourly data access); (5) Ethernet runs to plant room equipment (ASHP, MVHR) where the manufacturers support BMS-level integration. None of these adds material cost on a new build if planned at first-fix — all are expensive retrofits.
Privacy and data ownership
A real consideration in 2026: inverter manufacturer cloud APIs require account registration and stream usage data to the manufacturer. For homeowners who care about data sovereignty, local-only solutions (Modbus to Home Assistant) exist for all major brands. For others, the cloud APIs are convenient and well-supported. Either route is compatible with FHS compliance — there's no regulatory requirement on data architecture.
The next frontier — V2X
Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G) are mostly still 2027-28 capability for UK new builds. The hardware is here (Nissan Leaf, Kia, BYD all support V2X; Wallbox and EVTec are shipping bidirectional chargers), but DNO approval and tariff support are not yet at scale. New-build wiring should be specified to support 7 kW bidirectional EV charging — a 32A circuit to the EV charger location with provision for an isolator switch is the practical detail.
