Solar inverters and home energy monitors usually report through the manufacturer’s own cloud app, which works fine until you want to compare it against other home data, keep history beyond the app’s retention window, or the manufacturer changes the app entirely. Pulling that same data into a self-hosted dashboard on a VPS, using Home Assistant or Grafana and InfluxDB, gives you full ownership of the history and lets it sit alongside the rest of a smart home’s data on one screen.
The problem this solves
Most solar inverters, whether from SolarEdge, Growatt, Huawei, GivEnergy or another major brand, ship with a perfectly functional manufacturer app showing generation, consumption and battery state. The limitation isn’t that these apps don’t work, it’s what they don’t do: most cap how far back you can see history, none of them show your solar data alongside your smart home’s other data (when did generation peak relative to when the heating kicked in?), and switching brands later usually means losing access to your historical data entirely, since it lived inside that specific app the whole time.
Getting data out of the inverter in the first place
Most modern inverters expose their data through one of a few common methods: a local Modbus TCP interface (the same protocol covered in this site’s industrial guides, just applied at home scale), a manufacturer-provided local API, or in some cases an unofficial but well-documented integration the Home Assistant community has built and maintained. Which method applies depends entirely on your specific inverter brand and model, worth checking Home Assistant’s integration list or community forums for your exact hardware before assuming a particular approach will work.
Two viable architectures, similar to elsewhere on this site
Home Assistant route: if your inverter has a native or community-built Home Assistant integration, this is the simpler path, solar data appears directly as entities in Home Assistant, immediately available for the unified dashboard covered in Self-Hosted Smart Home Dashboard, alongside every other device in the house.
Grafana and InfluxDB route: for more detailed historical analysis, or if Home Assistant’s energy dashboard doesn’t offer the specific view you want, exporting inverter data into InfluxDB via Node-RED, following the pattern in Grafana + InfluxDB on a VPS, gives more flexible long-term querying and custom dashboard building than Home Assistant’s built-in energy views.
Many setups genuinely use both together: Home Assistant for day-to-day glanceable status, InfluxDB and Grafana for deeper historical analysis and year-on-year comparison.
Where the VPS fits
As with the rest of this site’s smart home content, the inverter itself and the local data collection stay at home, on the same local hardware running Home Assistant or Node-RED. The VPS’s role is the now-familiar one: a WireGuard tunnel, covered in Home Assistant Remote Access Without the Cloud, making this dashboard reachable securely from anywhere, useful for checking generation while away from home, or for sharing read-only access with an installer troubleshooting a fault remotely.
What a genuinely useful energy dashboard shows
- Real-time generation versus consumption, the core view most people check daily.
- Battery state of charge over time, for systems with storage, useful for understanding actual usage patterns rather than just the current snapshot.
- Daily, monthly and year-on-year totals, the kind of long-term comparison most manufacturer apps deliberately limit, and exactly where InfluxDB’s unlimited retention genuinely earns its place over an app’s capped history.
- Correlation with other home data, the genuinely unique benefit of self-hosting: seeing solar generation next to heating activity or EV charging on the same timeline, a view no manufacturer app offers since it only knows about its own device.
A note on export tariffs and billing accuracy
Worth being clear: a self-hosted dashboard is for your own visibility and analysis, it isn’t a substitute for your energy supplier’s official meter readings when it comes to export tariff payments or billing, which rely on certified metering, not a self-hosted Modbus reading. Use this guide’s setup for insight and monitoring, and your supplier’s official figures for anything involving actual payment.
Frequently asked questions
Will pulling data this way void my inverter’s warranty?
Generally no, reading data via a documented local interface like Modbus TCP is a standard, supported monitoring method most manufacturers explicitly allow, though it’s worth checking your specific inverter’s documentation if there’s any doubt, particularly before making any configuration changes rather than just reading data.
Can I still use the manufacturer’s app alongside this self-hosted setup?
Yes, reading data locally doesn’t typically interfere with the inverter also reporting to the manufacturer’s own cloud service, the two can run in parallel without conflict in most setups.
What if my specific inverter brand has no Home Assistant integration at all?
Worth checking the manufacturer’s own API documentation, since some, even without an official Home Assistant integration, still expose a documented local or cloud API that Node-RED can poll directly, a more manual but still workable path into the same kind of dashboard.
How much historical data is realistic to keep long-term?
InfluxDB handles years of data comfortably at typical solar reporting intervals (every few minutes), with the retention and downsampling approach covered in the Grafana/InfluxDB guide keeping storage requirements modest even over several years.
Does this work for EV charger monitoring too, not just solar?
Yes, many EV chargers expose similar local APIs or Modbus interfaces, and the same architecture applies directly, often genuinely useful alongside solar data to see how much of an EV’s charging is actually covered by home generation.
A worked example: spotting a problem the manufacturer app would have missed
A genuinely common real-world payoff worth illustrating: a panel or string of panels gradually underperforming, perhaps due to shading from a tree that’s grown taller over a couple of years, or a connector slowly degrading. Most manufacturer apps show today’s generation clearly but make a gradual decline over many months genuinely hard to spot, since there’s nothing dramatic happening on any single day to draw attention to it. A self-hosted dashboard with proper long-term history, the kind InfluxDB’s unlimited retention makes straightforward, makes this exact pattern visible: plotting year-on-year generation for the same month reveals a slow decline a day-to-day glance never would, often the first real signal something needs a closer look before it becomes a bigger, more expensive problem.
Setting realistic expectations for the Modbus connection itself
Most inverters exposing Modbus TCP do so over the local network, not requiring any special hardware beyond what’s already connecting the inverter to your home Wi-Fi or Ethernet. The actual Node-RED setup follows the same pattern covered in Building a Modbus-to-MQTT Gateway, just applied to a single inverter’s register map rather than industrial PLCs, with the specific register addresses needed coming from your inverter manufacturer’s Modbus documentation, which varies meaningfully between brands and is worth locating before starting.
Alerting on genuinely useful conditions, not just data collection
Beyond passive dashboards, the same Node-RED threshold-alerting pattern covered throughout this site’s other guides applies directly here: an alert if generation drops to near-zero during clear daylight hours (a likely inverter fault, not just cloud cover), or if battery state of charge behaves unexpectedly compared to its normal daily pattern. These are exactly the kind of conditions a manufacturer’s app rarely surfaces proactively, since it has no concept of “unusual for this specific system” the way a custom alert tuned to your own historical data can.
Is this overkill for someone who just wants to glance at generation occasionally?
Possibly, the manufacturer’s own app is genuinely fine for that specific, modest need. This guide earns its complexity for anyone wanting longer history, cross-device correlation, or a dashboard that doesn’t change shape every time a manufacturer updates their app.
Can this same dashboard show electricity usage from a smart meter, not just solar generation?
Yes, if your smart meter or an in-home display exposes a local API or Modbus interface, the same Node-RED and InfluxDB pattern applies, giving a genuinely complete picture of generation, consumption and net usage on one dashboard rather than three separate apps.
Do I need to be technical to read my inverter’s Modbus register map?
It helps to be comfortable following documentation closely, manufacturer Modbus register maps are typically a table of addresses and what each represents, not something requiring programming experience to interpret, just careful matching against your specific model’s documentation.
Is there a risk of damaging the inverter by polling it too frequently over Modbus?
Reading data via Modbus is a passive, read-only operation for monitoring purposes and carries negligible risk to the inverter itself; reasonable polling intervals (every few seconds to every minute, depending on your needs) are standard practice and well within what inverters are designed to handle.
A realistic first week with this setup
Most people building this for the first time spend the bulk of the effort on a single step: locating the correct Modbus register addresses for their specific inverter model and confirming a successful first read. Once that first successful read is achieved, typically a single number like current generation in watts showing up correctly in Node-RED, everything afterward, wiring it into InfluxDB, building Grafana panels, adding alerting, follows comfortably from patterns already covered elsewhere on this site. The genuinely inverter-specific part of this project is front-loaded into that first connection; everything downstream of it is the same general-purpose dashboard-building skill applicable to any sensor data, solar or otherwise.
A sensible first goal, rather than building the complete dashboard described earlier in this guide all at once: get one single value, current generation, reliably updating in a simple Grafana panel, refreshing every few minutes. Once that’s solid and trusted, expanding it into the fuller dashboard with battery state, historical comparison and alerting becomes a series of small, low-risk additions rather than one large, harder-to-debug undertaking.
Why this is worth the effort even for a modest solar installation
It’s tempting to assume this kind of dashboard only makes sense for a large commercial-scale installation, but the actual value, genuine long-term history, cross-device correlation, freedom from a manufacturer’s app limitations, applies just as much to a modest domestic rooftop system as to anything larger. The effort to set this up doesn’t scale meaningfully with system size, a small household installation takes essentially the same setup time as a larger one, meaning the relative payoff per hour invested is, if anything, slightly higher for the smaller, more typical installation this guide is actually written for.
The data cap consideration worth checking regardless
WireGuard’s own protocol overhead is small, but if the underlying device or router is also doing other things over the same cellular data SIM, a security camera streaming continuously being the most common example, the SIM’s actual data allowance matters far more than which remote-access method sits on top of it. Checking your specific data allowance against your devices’ actual usage pattern is a separate but equally important consideration alongside everything covered in this guide’s main comparison.
Making the final decision
Stripped to its simplest form, the question is: will this ever be more than one device, and do I expect the device count to grow? If genuinely a permanent single-device situation and the fixed IP SIM pricing is acceptable, that’s a reasonable, simpler choice. If there’s any realistic chance of growth, the VPS approach’s flat, non-scaling cost structure means choosing it from the start avoids the later work of migrating, which is straightforward but still avoidable overhead. Most readers of this site, given they’re already exploring self-hosted infrastructure, will find the VPS approach the more natural long-term fit, but the fixed IP SIM remains genuinely right for the specific, narrower case it was designed for.
For anyone still genuinely undecided: start with one entry-level VPS, follow the WireGuard Hub guide for your first device, and the practical experience of how easily additional devices join the same tunnel will make the right long-term choice obvious within a few weeks of actual use. The practical experience of one device on a tunnel is the best argument for the pattern this guide describes.