Hoymiles HM-800 Microinverter
The Hoymiles HM-800 is the most widely deployed microinverter in European balcony solar systems. It's the hardware that powered Germany's balcony solar boom — proven across 1.15 million installs, robust in UK weather conditions, and available in the UK at significantly lower cost than proprietary alternatives from EcoFlow or Anker. Two MPPT inputs, 800W output, Wi-Fi monitoring via the Hoymiles DTU or S-Miles Cloud app, and a 10-year warranty.
Pros
- 800W dual MPPT output — works with any combination of compatible solar panels
- Proven across millions of European installs — the most battle-tested microinverter in this class
- Significantly cheaper than proprietary microinverters from EcoFlow or Anker
- Wi-Fi monitoring via S-Miles Cloud app with real-time generation data
- Compatible with all standard MC4 solar panels — no proprietary connectors
- UKCA certified and BS 7671 Amendment 4 compliant
Cons
- No integrated battery — you'll need a separate Solarbank or similar for storage
- Wi-Fi setup can be temperamental on 5GHz-only routers — requires 2.4GHz
- UK-specific support routes through Amazon or Hoymiles international channels
- Monitoring data routes through Hoymiles cloud — no official local API
The Hoymiles HM-800 is the hardware that made Germany's balcony solar movement happen. While EcoFlow and Anker sell complete kits in attractive packaging, the Hoymiles is the component-level choice — the microinverter you buy when you want to pair it with the panels of your choice rather than whatever comes in the box.
Why Hoymiles dominates European plug-in solar
The HM-800 has been shipping into European balcony solar markets since 2022. By the time the UK's regulatory framework arrived in 2026, Hoymiles had accumulated field data from millions of installs across Germany, the Netherlands, Austria, and Switzerland. That's a meaningful reliability advantage over newer market entrants.
The dual MPPT design means each panel is tracked independently. If one panel is partially shaded, the other continues generating at full efficiency — unlike a string inverter where shading on one panel reduces the output of the entire string. For UK installs where partial shading from chimneys, trees, or neighbouring buildings is common, this matters.
Setup and monitoring
The HM-800 connects to the Hoymiles DTU (Data Transfer Unit, sold separately) which bridges the microinverter to your home Wi-Fi network. The DTU-WLite is the standard option for single-microinverter setups and costs around £30. Without it, you have no monitoring — buy it at the same time as the inverter. The S-Miles Cloud app provides real-time generation data, daily totals, and alerts. It's functional rather than polished but the data is accurate and the app is reliable.
The DIY kit approach
Buying a Hoymiles HM-800 plus two 400W panels plus mounting hardware typically costs £280–£350 depending on panel choice — significantly less than a complete EcoFlow or Anker kit at £419–£499. The trade-off is more components to source, no single point of warranty support, and a setup process that requires slightly more technical confidence. For anyone comfortable following instructions and connecting MC4 cables, the HM-800 DIY route is the best value plug-in solar build in the UK.
The verdict
The Hoymiles HM-800 is the microinverter of choice for UK buyers who want maximum value and are comfortable sourcing panels and mounting hardware separately. It's not as frictionless as EcoFlow's STREAM kit, but it's substantially cheaper and just as capable. The most popular microinverter in Europe didn't get there by accident.
