Quick Summary (TL;DR)
For Home Assistant integration rather than headline conversion efficiency, Fronius is the clearest conventional grid-tied choice in this comparison: its documented, local, read-only Solar API has a maintained Home Assistant integration, and many models additionally expose SunSpec Modbus TCP. Victron is the strongest option when the system is being designed around batteries, backup and local energy management: a compatible GX device running Venus OS can expose local MQTT to the official Victron GX integration. Neither statement means that every Fronius or Victron product works identically; the exact inverter, firmware, meter and gateway still matter.
Huawei can be a good monitored system, but its Home Assistant route is less straightforward: the widely used Huawei Solar integration is a third-party HACS project using Modbus, and connectivity, commissioning privileges and firmware can determine what is available. Solis requires the most careful communications-hardware check: SolisCloud API access is cloud-based, while local Modbus behaviour depends on the particular inverter and logger; Solis explicitly warns that enabling TCP/IP on the S2-WL-ST logger disconnects it from SolisCloud. Do not buy a model on the assumption that any Solis Wi-Fi stick provides simultaneous local Modbus and cloud monitoring.
This is a comparison of integration openness, commissioning access, reliability and total installed-system decisions, not an inverter-efficiency ranking. Solar generation, battery charging and grid import/export are different measurements. A Home Assistant dashboard is only as accurate as its meter locations and cumulative energy entities. For UK installations, the approved grid-connection arrangement, export limitation and qualified installer take precedence over any automation.
The comparison that matters: inverter, gateway, meter and permission
A solar inverter is not a self-contained Home Assistant product. The monitoring path may involve an inverter’s built-in Ethernet port, a separate communication dongle, a GX computer, an RS485 bus, an installer-owned cloud account, a revenue-grade meter or a hybrid battery controller. A data sheet saying Wi-Fi or Modbus is not proof that the feature is enabled for an owner or that a specific Home Assistant integration supports its register map.
Before comparing brands, decide whether you need (1) live solar power, (2) reliable daily and lifetime solar energy, (3) grid import/export, (4) battery state and charge/discharge flows, or (5) authorised control of setpoints. The first two can often come from an inverter alone; the others normally require more hardware or privileges. For a house with no battery, paying for advanced battery control is unnecessary. For a property with backup circuits and dynamic tariffs, the quality of the whole energy-management architecture may matter more than a simple production graph.
| Decision point | Fronius | Victron | Huawei | Solis |
|---|---|---|---|---|
| Most relevant home setup | Conventional string PV; GEN24 / GEN24 Plus options | Modular ESS, inverter/charger, solar chargers and backup | Integrated SUN2000/SUN5000 plus supported meter/battery ecosystem | Broad grid-tied and S6 hybrid ranges |
| Credible local monitoring path | Fronius Solar API JSON; optional SunSpec Modbus TCP | Venus OS GX local MQTT; optional Modbus TCP | Modbus RTU/TCP where supported and enabled; often HACS integration | Model-specific RS485 Modbus; some logger-specific TCP paths |
| Official Home Assistant integration | Fronius core integration | Victron GX core integration | No equivalent core Huawei Solar integration assumed here; community HACS project | No generic Solis core integration assumed here; custom/Modbus solutions require validation |
| Cloud needed for local path? | No, if Solar API is reachable on LAN | No, if GX MQTT is reachable on LAN | Not inherently for local Modbus; network/permission caveats | Not for a verified local Modbus path; SolisCloud API does need cloud |
| Additional component often needed | Smart Meter for grid-flow data | GX device; appropriate grid meter and other Victron devices | Compatible WLAN/FE dongle or wired RS485; Huawei meter | Datalogger, suitable Modbus interface or RS485 gateway |
| Largest integration trap | Solar API disabled on newer GEN24 firmware; wrong energy sensor | Mistaking an inverter/charger for a standalone network gateway | Assuming FusionSolar app access equals local Modbus and installer rights | Assuming any logger supports local TCP and SolisCloud simultaneously |
The table describes routes to investigate, not blanket support promises. Check the exact regional suffix, inverter firmware, communications module and installer configuration before signing an installation contract.
Fronius: the easiest conventional local integration to specify
Fronius publishes a <a href=”https://www.fronius.com/en-gb/uk/solar-energy/installers-partners/technical-data/all-products/system-monitoring/open-interfaces/fronius-solar-api-json-“>Solar API (JSON) specification</a>. The inverter or Datamanager serves a local HTTP interface for measurements such as AC power, voltage and energy, and may expose values from connected Smart Meters or other components. Home Assistant’s <a href=”https://www.home-assistant.io/integrations/fronius”>official Fronius integration</a> supports devices providing SolarAPI v0 or v1, including GEN24, and uses a LAN address rather than a Solar.web login.
That makes Fronius attractive if the purchasing requirement is keep the energy dashboard working when the internet fails. Ask the installer to enable the API, reserve the device’s DHCP address and demonstrate an actual Home Assistant connection before handover. Home Assistant’s documentation specifically notes that GEN24 devices delivered with firmware 1.14.1 or newer may require Solar API activation in the web interface. This is an easily missed commissioning task, not evidence that the inverter is cloud-only.
The distinction between the GEN24 and GEN24 Plus families also matters. Fronius markets <a href=”https://www.fronius.com/en-gb/uk/solar-energy/installers-partners/products-solutions/residential-energy-solutions/gen24plus-inverter-with-flexible-backup-power”>Primo GEN24</a> as single-phase and Symo GEN24 as three-phase; GEN24 Plus adds hybrid battery capability and potential Full Backup arrangements subject to model and extra equipment. The newer GEN24 SC versions have higher PV-input-current design for newer modules. Fronius states that Full Backup is not available on Symo GEN24 3.0–5.0 Plus. A PV Point output is not equivalent to whole-house backup. Confirm the exact AC rating, MPPT input currents, supported battery and backup topology for your country.
Solar API versus Modbus TCP
The Solar API is principally a read-only monitoring interface. The official Home Assistant integration can also use optional SunSpec Modbus TCP where enabled, including additional per-string/MPP tracker data. Fronius documentation now describes certain writable Modbus setpoints when the installer enables Inverter control via Modbus; those are not general-purpose permission to override the grid export arrangement. The AC power limit is a percentage of inverter output, not a guaranteed limit on export measured at the property boundary. The manufacturer’s dynamic power-reduction and DNO priority rules still govern export.
A good Fronius handover therefore includes separate answers for monitoring and control. Ask for Solar API access as a baseline; do not request write privileges unless there is a documented control design, a responsible installer and a tested fallback. If an automation fails or the LAN goes down, the inverter must still satisfy its commissioned grid settings.
Which Fronius energy entity belongs in the dashboard?
Home Assistant’s Fronius documentation recommends the inverter’s Energy total AC counter for solar production on a non-battery installation. A DC-side PV energy counter is not interchangeable with AC energy delivered to the home or grid: it can differ because of conversion losses. With hybrid storage, the documentation gives more specific instructions involving power-flow integration; blindly adding an inverter AC energy counter can count battery discharge as if it were fresh solar generation. Check the exact energy topology and avoid double-counting.
If you want grid import and export, confirm a compatible Fronius Smart Meter is fitted at the correct connection point and that the API actually exposes the required counters. An inverter output figure alone cannot tell you how much electricity the home purchased. The meter’s direction and phase mapping must be commissioned correctly. An additional independent meter may still be useful for billing reconciliation.
Victron: best fit for a designed energy-storage system
Victron should be evaluated as a system, not as a like-for-like substitute for a grid-tied PV string inverter. A common residential architecture combines a MultiPlus-II inverter/charger, suitable battery/BMS, PV chargers or AC-coupled PV, a grid meter and a Cerbo GX or another compatible GX device. Venus OS on the GX device aggregates the measurements and exposes supported services. The topology can handle complex ESS, backup and control use cases, but it is also more work to design and commission.
The <a href=”https://www.home-assistant.io/integrations/victron_gx”>official Victron GX Home Assistant integration</a> uses local MQTT, with automatic discovery where networking permits it. The documented connection uses MQTT over port 1883 when unsecured or 8883 with TLS on secured systems. Venus OS security profiles, pairing or credentials can affect setup. Home Assistant documents sensors for battery state of charge, grid power, solar charger yield, inverter state and some control entities; the exact list depends on installed devices and GX configuration.
Victron’s <a href=”https://www.victronenergy.com/media/pg/Cerbo_GX/en/configuration.html”>Cerbo GX configuration manual</a> documents separate switches for MQTT access and the Modbus TCP server. Do not assume both are on, or that buying a MultiPlus-II automatically includes a network-connected GX computer. If you already have a GX device, its MQTT interface may be the shortest path to Home Assistant. If you have only a charger or shunt, the <a href=”https://www.home-assistant.io/integrations/victron_ble/”>Victron BLE integration</a> supports certain Instant Readout devices, but BLE telemetry is not a substitute for a properly metered, system-wide ESS.
Victron’s local and cloud products are different
Victron’s VRM portal is useful for remote monitoring, historical reporting and supported forecasts. The <a href=”https://www.home-assistant.io/integrations/victron_remote_monitoring”>Home Assistant Victron Remote Monitoring integration</a> is a cloud service and currently concentrates on forecasts, not the same direct telemetry as the local GX integration. It requires an access token and at least 30 days of appropriate VRM history for forecast availability. An installation can use local GX monitoring and VRM together; a VRM login is not a prerequisite for LAN MQTT telemetry.
This separation makes a Victron system attractive for users who want local automations and optional remote services. It does not mean that every control exposed by MQTT should be automated. ESS setpoints, charge limits, relay outputs and generator control can have safety and battery-longevity implications. Keep approved inverter firmware and protection settings under the installer’s control, and build Home Assistant automations with bounded values, clear fail-safe behaviour and manual override.
Costs hidden in a Victron quote
Compare complete system bills of materials, not the price of a MultiPlus-II against a single hybrid inverter. Include the GX device, battery and BMS, grid meter, DC fusing and disconnects, protection equipment, appropriate cabling, enclosure, AC changeover/backup distribution, commissioning and any separate MPPT controllers. The inverter/charger alone does not establish how much PV was generated. A third-party AC-coupled PV inverter may need its own telemetry and a correct measurement boundary.
For a small roof with no battery and no requirement for islanded operation, this complexity may be unnecessary. For a home with critical-load circuits, variable tariffs, a generator or planned battery expansion, Victron can justify the additional engineering—provided a qualified designer checks the local grid code and supported ESS topology.
Huawei: strong integrated ecosystem, more commissioning friction
Huawei’s SUN2000 family includes distinct single-phase and three-phase products, with regional differences in battery compatibility and communication hardware. For example, the official <a href=”https://solar.huawei.com/pl/products/SUN2000-5-12K-MAP0/specs/”>SUN2000-5–12K-MAP0 specifications</a> describe a three-phase range and particular LUNA2000 battery families. That specification should not be applied to every older SUN2000-L1, M1 or newer SUN5000 model. The official <a href=”https://solar.huawei.com/it/products/SmartDongle-WLAN-FE/specs/”>Smart Dongle WLAN-FE compatibility list</a> spans several families but still has exact model limits.
The practical Home Assistant route many owners use is the <a href=”https://github.com/wlcrs/huawei_solar”>Huawei Solar community integration</a> installed through HACS. It talks Modbus over supported serial or network paths. This is not the same as a manufacturer-backed core Home Assistant integration. The project notes that connectivity can be via inverter RS485 or a network path, that some connections use ports 502 or 6607, and that firmware from 2023 onwards is its supported baseline. It also warns that a Huawei Modbus device may accept only one connection at a time. The correct IP address, slave ID, firmware and installer permissions matter.
Huawei’s own <a href=”https://info.support.huawei.com/Energy/info/en_US/solar/docView/EDOC1100612098″>FusionSolar installer manual</a> describes configuring Modbus TCP on the WLAN/FE Smart Dongle for third-party management. It is an installer-level configuration with security consequences, not a feature you should assume an ordinary FusionSolar owner account can change. If you want advanced HACS controls, the community project describes elevated permissions and, for some TCP paths, installer credentials. Never publish those credentials in configuration examples or expose Modbus TCP to the internet.
What to ask a Huawei installer before paying
Have the installer state in writing: the full SUN2000/SUN5000 part number; the dongle type and firmware; whether a supported Modbus TCP or RTU interface will be enabled; who retains the commissioning password; whether third-party polling can coexist with the monitoring app and other equipment; and which battery and power-meter registers will be available. Ask for a witnessed demonstration of PV watts, lifetime kWh, grid direction and battery SoC if those are part of the contract.
The result can be an excellent local monitoring setup, but the owner should not be left discovering after installation that the installer disabled Modbus, locked access or chose a communications device that the intended integration cannot use. Software updates may change behaviour, so agree who will support the connection after firmware changes.
Solis: buy the exact inverter and logger combination
Solis sells both conventional grid-tied inverters and multiple hybrid families. The UK <a href=”https://www.solisinverters.com/uk/energy_storage_inverters19/S6-EH1P%283-10%29K-L-PLUS_uk.html”>S6-EH1P(3–10)K-L-PLUS</a> is a single-phase low-voltage battery hybrid series, not a generic description of every Solis S6 product. Its 40–60 V battery architecture should not be confused with high-voltage three-phase models. Check the manufacturer’s battery compatibility list, inverter’s UK-specific certificate and supported communication hardware for the exact revision offered.
For cloud monitoring, Solis offers SolisCloud. The official <a href=”https://solis-service.solisinverters.com/en/support/solutions/articles/44002212561-request-api-access-soliscloud”>SolisCloud API access procedure</a> says end users can request API access via a support ticket and that API access does not confer remote control. This is a cloud API path, not local polling. An unofficial Home Assistant integration built around the API may work for monitoring, but it inherits internet access, authentication, service availability and rate-limit considerations.
For local access, look for a documented Modbus RTU RS485 port or supported logger-specific Modbus TCP mode. Solis’s official <a href=”https://solis-service.solisinverters.com/en/support/solutions/articles/44002530087-solis-s2-wl-st-modbus-tcp-communication”>S2-WL-ST Modbus TCP procedure</a> contains a crucial caveat: enabling TCP/IP causes the logger to disconnect from SolisCloud. That statement is specific to the documented logger mode; it should neither be ignored nor extrapolated to every Solis logger. If the installer promises both cloud and local Modbus, ask them to identify the exact hardware and demonstrate both working concurrently.
RS485 is a project, not just a plug-in feature
A wired RS485 connection may need a correctly isolated interface, appropriate twisted-pair cable, termination, addressing and a Modbus-to-Ethernet gateway. The inverter’s communication port may already be occupied by a logger or meter, and an unsupported parallel connection can cause intermittent polling. The register map can differ across Solis generations and hybrid variants. Generic community YAML from a different model can produce plausible but wrong numbers. Home Assistant’s <a href=”https://www.home-assistant.io/integrations/modbus”>Modbus documentation</a> explains the difference between Modbus TCP, serial RTU and transparent RTU-over-TCP bridges.
Solis can make economic sense in a professionally specified installation, but for a buyer who places a high value on uncomplicated, fully local Home Assistant support, the burden of proof should be on the exact Solis model and communications bundle. A low inverter-only quotation is not the installed cost of dependable monitoring.
Which readings are genuinely available?
The word integration can hide major differences in data completeness. A PV inverter typically knows its own AC output. It may know DC string voltage/current, but not household load. A grid meter knows exchange with the public network, but not the battery’s DC flows. A hybrid controller may expose state of charge, yet still omit the cumulative kWh counters Home Assistant needs. Do not infer missing values from an attractive energy-flow animation.
| Reading | Hardware/data source normally needed | Common failure | Practical acceptance test |
|---|---|---|---|
| PV instantaneous power (W) | Inverter or PV charger | Wrong unit or stale cloud update | Compare local inverter display during daylight |
| Lifetime solar energy (kWh) | Cumulative inverter/charger energy counter | Daily counter mistaken for lifetime | Confirm it increases across several days without unexpected reset |
| Grid import and export (kWh) | Bidirectional meter at point of connection | CT orientation, missing phase, net-only register | Compare direction under known import/export conditions |
| Battery state of charge (%) | Compatible BMS/hybrid or GX | SoC confused with battery voltage estimate | Compare battery manufacturer’s own display |
| Battery charge/discharge energy (kWh) | Dedicated counters or signed power integration | DC versus AC boundary and round-trip loss | Validate sign and totals across a complete charge/discharge cycle |
| Household consumption (W/kWh) | Metered grid + PV + battery flow model | Adding values with wrong signs or duplicated energy | Compare against independent whole-home meter |
| Export limit and inverter control | Commissioned controller with permission | HA command conflicts with DNO export cap | Have installer verify approved control priority and fail-safe |
A useful rule is to keep energy counters separate from instantaneous power. Watts describe what is happening now; kilowatt-hours accumulate over time. Home Assistant’s <a href=”https://www.home-assistant.io/docs/energy/”>Energy dashboard documentation</a> explains how a power sensor can be integrated into an energy estimate if no counter exists. Integration introduces error when updates are sparse or values become unavailable. A native lifetime kWh counter with correct units and statistics is preferable where available.
Energy dashboard setup: avoid the solar/battery double-count
For a simple grid-tied system without storage, use the inverter’s appropriate cumulative AC solar production energy entity. Use separate grid-import and grid-export cumulative entities from a correctly located meter. Do not add an inverter’s instantaneous watt sensor to a field expecting kWh. For a battery system, first draw a power-flow diagram with the locations of all meters. Decide whether PV production is measured before or after the hybrid inverter’s battery flow, and ensure battery discharge is not recorded as newly generated solar electricity.
Home Assistant’s <a href=”https://www.home-assistant.io/docs/energy/faq/”>energy FAQ</a> lists the attributes required for energy entities, including device_class: energy, an appropriate kWh unit and state_class: total or total_increasing. The correct state class depends on the source sensor’s behaviour; do not force total_increasing onto a counter that decreases or is net-signed without understanding its semantics. Check Settings → Developer tools → Statistics for errors before declaring a sensor suitable.
Consider a house where PV produces 18 kWh over a day, 7 kWh is exported and 11 kWh is consumed locally. If the battery also discharged 4 kWh that came from yesterday’s solar, treating that discharge as another 4 kWh of today’s PV would inflate today’s solar figure. Conversely, if a hybrid inverter reports only AC power delivered after battery blending, the AC inverter counter may not isolate actual panel generation. This is why the Fronius integration’s battery-specific guidance and the Victron system meter topology matter more than the brand label.
For a full troubleshooting procedure, see our existing <a href="https://esp32AliExpress price.co.uk/home-assistant-energy-dashboard-correct-grid-solar-and-battery-entities/">Home Assistant Energy Dashboard entity guide</a>. If your setup includes a separate DIN-rail meter, the <a href="https://esp32AliExpress price.co.uk/esp32AliExpress price-modbus-energy-meter-home-assistant-sdm120-sdm630AliExpress price/">SDM120/SDM630AliExpress price Modbus guide</a> covers a different, independent measurement path. Only use these links as supporting guides, not as proof of compatibility with any of the four inverter brands.
Local versus cloud: test the actual failure modes
Local should mean that Home Assistant obtains values directly over the home network or wired bus without asking a vendor’s internet service for every reading. It does not automatically mean that the inverter will buffer readings for Home Assistant, that every API feature works offline, or that the integration will restore data missed during an outage. A local interface can also fail if the inverter powers its network card down at night or the Wi-Fi signal is poor.
| Failure event | Local Solar API / MQTT / Modbus | Cloud API | What to test |
|---|---|---|---|
| Internet disconnected, LAN running | Should continue if local interface stays powered and enabled | Usually stops updating | Unplug WAN briefly without altering LAN; observe timestamps |
| Home Assistant restarts | Poll/push should resume; missed samples may not be recovered | May refill some history if service supports it | Restart and check counters/statistics |
| Router or Wi-Fi failure | Network path fails; wired serial may continue | Cloud logger may also lose uplink | Confirm physical path and wired fallback |
| Inverter sleeps at night | Some entities unavailable; cumulative totals should recover | Cloud may show delayed totals | Compare first morning readings and total counter |
| Vendor changes cloud API | Local documented path may be unaffected | Tokens, endpoints or limits may break | Ask for published API support and change policy |
| Installer changes firmware | Interface or permissions may change | Cloud account may continue | Re-run commissioning acceptance tests |
For a house where solar surplus triggers EV charging or heating, a cloud reading delayed by several minutes can cause unwanted grid import. Local data is preferable, but do not write an automation that starts a large load from a single positive power sample. Use a sustained surplus threshold, minimum run time, hysteresis and a fallback when the sensor becomes unavailable. A dedicated EV charger’s approved load management should still protect the supply independently of Home Assistant.
Single-phase, three-phase and regional approval
In the UK, a typical domestic supply is single-phase 230 V, but larger properties may have three-phase. Fronius Primo and Symo, Huawei SUN2000-L1 versus MAP0, and Solis single-phase versus three-phase families are not interchangeable merely because their rated kW numbers are similar. Victron systems also require an approved configuration for each phase and any islanding/backup arrangement. The inverter’s AC output, phase balance, export limit and protection requirements must match the site and the network operator’s connection permission.
In Great Britain, the installer must determine whether the installation falls under G98 or requires a G99 application; G98 generally covers qualifying microgeneration at no more than 16 A per phase, while larger or non-qualifying installations use G99. The official <a href=”https://www.gov.uk/government/publications/register-energy-devices-in-homes-or-small-businesses-guidance-for-device-owners-and-installation-contractors/register-energy-devices-in-homes-or-small-businesses-guidance-for-device-owners-and-installation-contractors”>UK government guidance</a> explains DNO notification and application routes. <a href=”https://connections.nationalgrid.co.uk/g99-connection-procedures”>National Grid’s G99 guidance</a> covers higher-rated generation and storage connections. Export limitation arrangements may involve G100 and site-specific approvals. Do not assume that a Home Assistant automation satisfies a DNO’s export-control requirement.
For EU markets, check the specific country’s grid code, anti-islanding certification, voltage/frequency settings, battery approvals and warranty terms. A UK-branded model with G98/G99 documentation is not automatically authorised in Greece, Germany or Ireland; similarly, a CE marking is not a complete grid-connection approval. Ask the installer for the full model’s current certificate and the utility’s approved settings. Modbus access must never defeat anti-islanding or statutory protection.
Real cost comparison: what should be in the quote?
Retail inverter prices alone are a poor buying guide. A complete installation can require communication accessories, energy meters, DC isolators, AC protection, surge protection, cabling, mounting, a battery, backup changeover, commissioning and network integration. Some items are mandatory because of site design and local regulation, not optional smart-home extras. Rather than inventing a UK street price, use a line-by-line quote comparison.
| Cost/ownership line | Fronius | Victron | Huawei | Solis |
|---|---|---|---|---|
| Inverter/core hardware | Exact Primo/Symo GEN24/Plus variant | Inverter/charger plus any PV charger/inverter | Exact SUN2000/SUN5000 and compatible battery | Exact grid-tied or S6 hybrid SKU |
| Local data gateway | Usually built-in networking on compatible models | GX device generally required for system MQTT | Supported dongle or serial interface | Logger or serial gateway; model-specific |
| Grid meter | Often Fronius Smart Meter for import/export | Supported meter as designed in ESS | Compatible Huawei power sensor/meter | Approved meter/CT arrangement |
| Battery system | Plus/hybrid compatibility and backup components | Battery, BMS, DC protection and ESS design | Supported LUNA battery and controllers | Matching voltage/BMS; low/high-voltage distinction |
| Network labour | Enable Solar API; reserve IP; verify entities | GX security, MQTT and meter mapping | Installer Modbus permission and dongle setup | Logger/RS485 setup, register mapping, cloud trade-off |
| Long-term ownership | Local API and firmware support | System configuration complexity and GX maintenance | HACS and firmware/permissions dependency | Cloud API and logger/reg-map dependency |
Ask each installer for two totals: the complete solar installation and the incremental cost of obtaining the Home Assistant data you actually need. Include ongoing cloud/API fees if any are contractually specified, maintenance, firmware support and whether the installer will restore integrations after warranty service. If one quotation omits a grid meter while another includes it, the offers are not functionally equivalent.
Installer handover checklist: demand a working demonstration
- Record the full part number, region, firmware, serial number, communications hardware and meter type, without publishing serials or passwords online.
- Confirm the authorised G98/G99 or local grid-code configuration, export limit, protection settings and any approved battery/backup scheme.
- Give the inverter/gateway a stable local IP reservation and document its physical network connection. Prefer Ethernet where available and sensible.
- Confirm which interfaces are enabled: Solar API, Modbus TCP/RTU, Venus MQTT or SolisCloud API. Record who is permitted to change them.
- In Home Assistant, demonstrate solar power W, cumulative production kWh, grid import/export and battery state if applicable. Check the units, sign and meter boundary.
- Briefly isolate internet access while keeping the LAN active. Verify that claimed local telemetry continues, then restore service.
- Check how the system behaves at night and after Home Assistant restart. Confirm that cumulative energy counters do not falsely reset or double-count.
- Document the firmware update policy, installer contact, integration support boundaries and credentials transfer. Keep cloud and installer credentials private.
- Ensure Home Assistant cannot override safety-critical limits, anti-islanding or a mandated export restriction. Prefer read-only integration unless control has been designed and tested.
- Save an as-built single-line diagram and a short table of sensor names and measurement locations. This will save hours when adding a battery or EV charger later.
The demonstration matters more than a sales promise of “Home Assistant compatible”. Ask to see the exact entities on your system, not a screenshot of someone else’s inverter with a different firmware version.
Recommendations by buyer scenario
Existing PV with no battery and a local-only dashboard
If choosing new hardware primarily for a straightforward, supported Home Assistant integration, Fronius with enabled Solar API is the most direct fit among these four. A supported GEN24 installation can expose data without a cloud login, and optional SunSpec provides additional detail. But do not replace a functioning inverter just to get telemetry: an independent energy meter or a supported existing gateway may be much cheaper and less disruptive. Compare options in our <a href="https://esp32.co.uk/best-home-energy-monitors-for-home-assistant-shelly-vs-emporia-vs-modbus/">whole-home energy-monitoring guide</a>.
Battery storage, backup circuits and future control
Victron is worth a serious design review when a modular ESS, multiple power sources, backup distribution or sophisticated local energy management is central to the project. The GX ecosystem provides strong local visibility, but cost and complexity rise with the number of components. Ask for a full schematic and commissioning plan rather than buying a MultiPlus-II and hoping it solves every problem. Fronius GEN24 Plus, Huawei and Solis hybrid solutions may be more compact when the battery and backup needs fit their approved ecosystems.
Installer-led integrated solar and battery package
Huawei may suit a buyer prioritising a matched inverter, battery and monitoring ecosystem, provided the installer commits to enabling a tested local Modbus route. If the installer cannot guarantee owner access, evaluate the system on its native FusionSolar experience and treat HACS support as a bonus, not a contractual certainty. This is especially important if you plan to use local data for automation rather than occasional charts.
Price-sensitive installation with specific local telemetry requirements
Solis is a candidate when the overall installed quote is attractive and the installer can demonstrate the precise local interface. Demand the logger part number, the Modbus register documentation and confirmation of whether local access disables SolisCloud. A cheap inverter plus unsupported dongle can become an expensive integration project. If the seller cannot prove the data path, budget for an independent meter rather than inventing an API capability.
Common mistakes to avoid
“It has Wi-Fi, therefore Home Assistant can read it locally.” Wi-Fi may only connect a vendor logger to a cloud portal. Ask for the exact local protocol and whether it is enabled.
“All Modbus devices work the same.” The transport is standardised, but register maps, scaling, units, permissions, device IDs and supported function codes are not universal. One model’s register map is not proof for another.
“The inverter’s power figure equals household consumption.” It does not. You need a grid meter and a coherent battery/PV model. A CT around the wrong conductor or phase can reverse or omit flows.
“A hybrid inverter always offers full backup.” Backup capability depends on battery, approved changeover hardware, protected circuits and specific model limits. A PV Point outlet, an EPS terminal and a whole-house islanding scheme are different things.
“If I can write a Modbus register, I may override the export limit.” Do not. A grid-code setpoint and DNO-approved export control are not experimental Home Assistant settings. Use read-only monitoring until a qualified installer has documented the permitted control architecture.
“Cloud access is useless.” Cloud portals may provide useful remote alerts, warranty diagnostics and historical information. The problem is dependence on cloud polling for fast local automations, not the mere existence of a cloud option. Local and cloud monitoring can coexist where the hardware supports both.
Frequently asked questions
Which of these has the most straightforward native Home Assistant integration?
For a conventional grid-tied solar inverter, Fronius’s official Solar API integration is a clear starting point. For a system designed around Victron batteries and ESS, the official Victron GX integration provides local MQTT. Neither choice guarantees that every desired battery, grid or per-string counter exists without the correct connected hardware.
Can Huawei Solar run in Home Assistant without the internet?
Yes, a supported local Modbus route can operate without internet access, but the commonly used Huawei Solar integration is a community HACS project, not a core vendor integration. Exact dongle, firmware, Modbus setting, connection count and commissioning permissions must be checked. FusionSolar app access alone does not prove that the local path is available.
Does SolisCloud API access give me local control?
No. Solis describes its SolisCloud API as an end-user cloud API and explicitly distinguishes it from remote control. Local Modbus is a separate, model-specific communications question. The documented S2-WL-ST TCP procedure can disconnect the logger from SolisCloud, so do not assume simultaneous operation.
Do I need an extra electricity meter?
If you only want solar inverter production, often not. For accurate grid import/export and household energy balance, a suitable meter at the grid connection point is normally required. Battery flows may require additional counters. The model and installation position are more important than the number of dashboard entities.
Is a three-phase inverter better for Home Assistant?
Not inherently. Three-phase hardware should be selected because of the electrical supply, generation rating and approved system design. A three-phase meter needs correct per-phase voltage/current association. Software integration quality depends on the inverter’s interface, not simply on its number of phases.
Should I buy the inverter with the highest advertised efficiency?
Efficiency matters to solar design, but this article does not rank inverter conversion performance. PV array orientation, MPPT limits, shading, thermal conditions, battery losses, warranty, grid approval and installed cost can outweigh small nameplate differences. Request an installer-produced yield model and the exact manufacturer’s regional data sheet.
Official documentation and further reading
- <a href=”https://www.home-assistant.io/integrations/fronius”>Home Assistant: Fronius integration</a> — supported Solar API and optional Modbus behaviour, energy sensor selection and control warnings.
- <a href=”https://www.fronius.com/en-gb/uk/solar-energy/installers-partners/technical-data/all-products/system-monitoring/open-interfaces/fronius-solar-api-json-“>Fronius: Solar API (JSON)</a> — vendor description of the open local API.
- <a href=”https://www.fronius.com/en-gb/uk/solar-energy/installers-partners/products-solutions/residential-energy-solutions/gen24plus-inverter-with-flexible-backup-power”>Fronius: GEN24 / GEN24 Plus</a> — regional product families and backup restrictions.
- <a href=”https://www.home-assistant.io/integrations/victron_gx”>Home Assistant: Victron GX integration</a> — local MQTT prerequisites and supported entity classes.
- <a href=”https://www.victronenergy.com/media/pg/Cerbo_GX/en/configuration.html”>Victron: Cerbo GX configuration</a> — MQTT and Modbus TCP settings.
- <a href=”https://solar.huawei.com/it/products/SmartDongle-WLAN-FE/specs/”>Huawei: Smart Dongle WLAN-FE specifications</a> — current manufacturer compatibility list (verify regional part numbers).
- <a href=”https://info.support.huawei.com/Energy/info/en_US/solar/docView/EDOC1100612098″>Huawei: FusionSolar installer manual</a> — Modbus TCP commissioning and third-party integration settings.
- <a href=”https://github.com/wlcrs/huawei_solar”>Huawei Solar community Home Assistant integration</a> — third-party support and firmware/connection caveats; not an official Huawei product.
- <a href=”https://www.solisinverters.com/uk/energy_storage_inverters19/S6-EH1P%283-10%29K-L-PLUS_uk.html”>Solis: UK S6 low-voltage hybrid series</a> — manufacturer product description.
- <a href=”https://solis-service.solisinverters.com/en/support/solutions/articles/44002212561-request-api-access-soliscloud”>Solis: SolisCloud API access</a> — end-user cloud API and access procedure.
- <a href=”https://solis-service.solisinverters.com/en/support/solutions/articles/44002530087-solis-s2-wl-st-modbus-tcp-communication”>Solis: S2-WL-ST Modbus TCP instructions</a> — logger-specific cloud disconnection caveat.
- <a href=”https://www.home-assistant.io/docs/energy/”>Home Assistant: Energy dashboard</a> and <a href=”https://www.home-assistant.io/integrations/modbus”>Modbus integration</a> — measurement classes and wired/network integration.
- <a href=”https://www.gov.uk/government/publications/register-energy-devices-in-homes-or-small-businesses-guidance-for-device-owners-and-installation-contractors/register-energy-devices-in-homes-or-small-businesses-guidance-for-device-owners-and-installation-contractors”>UK government: registering generation and storage</a> — DNO application and notification responsibilities.
Editorial verification: manufacturer and Home Assistant documentation checked 14 October 2026. Features, firmware and regional certifications can change; confirm the exact SKU and current installation manual before ordering. No product was independently bench-tested for this guide, and no unverified prices or yield claims are presented.