Hoymiles 800W Inverter: Setup, G98 and ENA Registration Explained

The Hoymiles 800W inverter in our plug-in solar kits is the HMS-800-Pro, a micro-inverter that turns the direct current from up to six semi-flexible panels into mains electricity through an ordinary UK plug. Ravair Solar is a UK supplier of plug-in solar systems, and this guide explains what the inverter does, why its registration on the ENA register matters, what G98 notification to your network operator involves, and what the supplied manuals cover when you set it up. We supply the kit and the manuals; we are not installers.

What does the micro-inverter actually do?

A micro-inverter is a small inverter that sits at the panels rather than in a cupboard, converting their direct current into the alternating current your home uses. In a plug-in kit it does three further jobs that a panel cannot: it matches the grid's frequency, it shuts itself down if the mains fails so that no power is pushed into a dead line, and it never puts out more than its rated output. In our 720W full system, six 120W semi-flexible panels feed one HMS-800-Pro rated at 800W, and the inverter ends in a UK plug.

That is why the inverter, not the panels, is where the rules concentrate. The Government's interim product specification, in force since 27 August 2026, limits a plug-in device's inverter to 800VA and 3.5A of output, requires anti-islanding protection that cuts power within 100 milliseconds of unplugging, and requires a manufacturer-fitted non-rewireable BS 1363 plug with a fuse no larger than 5A. Every one of those is an inverter property. Our guide to the 2026 rules goes through the framework in full.

Why does ENA registration matter?

The Energy Networks Association is the body whose engineering recommendations govern how small generators connect to the low-voltage network in Great Britain, and its register lists the inverters that have been type-tested against those requirements. Our product page states that the Hoymiles HMS-800-Pro is registered on the UK ENA Register. An inverter that is on the register can be notified to your network operator as a known, tested device; one that is not has to be treated as unknown, which in practice means it cannot be notified properly.

This is the check we would make on any plug-in kit, from us or from anyone else: which inverter model is in the box, and is that model on the register. Cheaper inverters that are not registered exist, and we would rather say so than sell one. The ENA and G98 requirements are product-specific facts about this inverter; they do not mean every solar product carries identical connection requirements, so check the model you are actually buying.

What is G98, and who do I notify?

G98 is the ENA's engineering recommendation for connecting small generators to the low-voltage network. Under it, small systems are notified to the Distribution Network Operator - the company that owns and runs the wires in your area, which is not the same as the supplier you pay your bill to - rather than applied for in advance. Our product page refers to G98 registration within 28 days of installation for the HMS-800-Pro.

Notification is a form to your DNO with the details of the inverter and where it is installed. If you do not know which company is your DNO, it is the one named on your meter or in the "loss of supply" number on your bill, and the ENA publishes a way to find it by postcode. Solar systems should be installed and connected in accordance with the applicable UK electrical, network and manufacturer requirements; where grid-connected equipment requires notification or registration, the relevant ENA or DNO process must be followed. It is the step people most often skip, and it is not optional.

What do the manuals cover on setup?

The kit ships with an installation manual and the inverter's own manual, and those - not this article - are the instructions. In outline they cover positioning the inverter close to the panels, connecting the panel leads to the inverter's inputs, routing the cable to the socket, plugging in, and pairing the inverter with the Hoymiles app or cloud platform so that you can see what the panels are producing. We give no technical advice beyond those manuals, and we do not provide installation or bespoke electrical design.

Two things the manuals cannot judge for you. First, whether the socket and circuit you intend to use are in a fit state: the Government's framework assumes a sound existing installation, and if anything about the wiring is old, damaged or unknown, a qualified electrician is the right person to look at it before anything is plugged in. Second, whether you have permission to fix panels where you want them - a landlord, freeholder or managing agent question for flats and rentals.

Why is monitoring built in?

Because a plug-in system has no display of its own, the HMS-800-Pro's app and cloud monitoring is how you know it is working. It shows what the inverter is putting out, so you can see the panels producing on a bright morning and see them stop when a cloud crosses. That matters for two reasons: it tells you the system is running at all, and it lets you match your daytime use to what the panels make, which is where a small system without a battery earns its place.

We publish no output or savings figures, because what a system produces depends on its orientation, shading, season and location - the monitoring shows you your own numbers rather than anyone's estimate. Anything that promises a plug-in kit will cover its own cost, or electricity at no cost, is guessing.

Can I buy the inverter on its own?

Yes. The Hoymiles 800W inverter is listed separately for customers who already have suitable panels, alongside the 120W semi-flexible panel and the 720W full system; prices are on the solar products listing because they change - at the time of writing the inverter is listed at £139.50 and the full system at £600. Electrical products carry a one-year warranty under our general returns policy; the balcony system is advertised with a 10-year warranty on its product page, and warranty terms vary by product, so check the individual listing.

If you are pairing the inverter with your own panels, note that the specification allows up to 2,000W of panels behind an 800VA inverter, and that more panel capacity does not raise the inverter's output - it only reaches its ceiling earlier in the day. Delivery is UK-wide, free on orders over £200, with a mainland UK next-day target for orders finalised by 12pm.

Frequently asked questions

Solar regulations and electrical requirements can change. The information in this article is provided for general guidance and should not be treated as electrical, legal or installation advice. Always check the latest UK Government, Energy Networks Association and relevant electrical guidance before connecting a solar system to a property. Where electrical work is required, use a suitably qualified electrician.

See the inverter, panels and full system, or call 01892 750777 with a question about your setup.