Is this the future of DIY Energy projects?

Our first impressions with the AP systems EZHI Hybrid Microinverters.

After months of trying and failing, DIY Home Energy UK finally got hold of an APsystems EZHI. Ever since catching the plug in solar bug, we've wanted to go onto the next stage into a project more challenging and something more capable than just the plug in 800w solar systems. After much time researching, the EZHI stood out as one of the most interesting products currently out there, although it was not at the time available in the UK, starting this mission to get one imported!

The reason it was so attractive for a project is because the EZHI is what we believe to be the future of plug in solar and DIY home energy. Rather than offering just a plug in battery or just a plug in solar system, it combines both into a hybrid microinverter platform that has the potential to keeping growing alongside a homeowner's energy needs, includoing an off-grid functionality to cover all avenues.

There are already products on the market from companies such as EcoFlow and Zendure, many of which include MPPT solar inputs and battery storage. However, when comparing the cost per kilowatt hour of storage, they did not appear cheap and we disliked how they require users to commit to a single battery ecosystem, limiting future upgrade options.

That is where the EZHI really shines as a unique product compared to what is currently on the market.

A More Modular Approach

One of the biggest attractions of the EZHI for us is its flexibility.

To summarise just some of its capabilities:

• Two 600W MPPTs for 1200w of direct solar input

• 800W AC output with an option to go high power, to 1200w for built-in systems

• An off-grid functionaility, with a power strip able to provide power without grid-power needed

• The ability to then plug in a 800w microinverter into this off-grid strip to feed into the system, bringing the total solar input to 2000ws

• Battery storage flexibility, offering interoperanility with a range of battery manufacturers products, including Pylontech, Dyness, Felicity, Epever and more

• Modular batteries can expand storage capability into the potentially 100s of Kwhs

• Home Assistant integration and local API control, opening up a world of possibility for technical users, including running it as an AC-coupled battery, overnight charging and even integration with tariffs such as Octopus Agile to create logic for half hourly decisions on charge and discharge.
  

For anyone who enjoys continous developing and building, these capabilities offer a lot of tinkering, optimisation and expansion over time.

In this instance, we wanted to build it as an AC coupled battery system that can do overnight on cheaper electricity tariffs, soak up excess generation from the existing Hoymiles microinverters during the day, and discharge during the day tariffs to keep the import as close to 0 as possible.

Installation Experience

The physical installation itself was pretty straightforward once all the correct parts had been ordered and the battle to import thek it had been won!

As the plug in version, it was largely a case of connecting everything together before turning attention to the software side of the project. At DIY Home Energy UK, we did end up connecting the whole system fully on a dedicated circuit with an AC isolator and its own bidirectional RCBO to run it in 1200 W mode safely, but this part was done by a qualified professional and we tested the 800 W plug in mode for a full day beforehand.

Another point to note about installation is that if you are connecting up your home battery, nearly all home batteries are Class I devices, meaning they should be earthed correctly. Ensure your battery is earthed correctly and any metal enclosures bonded by a professional if you intend to use the EZHI with a battery.

On the APmeter setup, this particular kit arrived with the three phase APmeter. We first thought this might be a problem, but it turned out to be a non-issue.We just fit the Phase 1 CT clamp and left the remaining two unused allowed the meter to operate perfectly on a standard single phase UK installation.

On reflection, the physical installation ended up being the easiest part. There's some good videos by AP Systems themselves detailing how the parts go together, and the plug in element and standard app operation is easy to set up.

The EZHI paired with the Pylontech 5000C. 1200Ws of output with 5.12 Kwhs of battery that can easily be expanded with more batteries or up to 2000ws of solar, all DIY for less than £1500!

Integrating with Home Assistant

Getting the hardware connected was only part of the project.

As we already have a plug in solar setup with a Hoymiles inverter, we wanted to run the EZHI alongside a Pylontech US5000C as an AC coupled retrofit battery system. . The AP EasyPower app isn't really set up to run the EZHI in this way yet, so some customisation and bodging around was needed to set it up in this way. Luckily the EZHI has a strong community in Germany and so there was forums and HACS integrations which were really useful. We found the following the best integration available, and it really helped with building dashboards and setting up the EZHI as an AC-coupled battery - https://github.com/kamilkosek/EZHI

However, whilst there was a clear community integration to setting up the EZHI on Home Assistant, there was no Home Assistant integration available for the APmeter which was needed to tell the EZHI when it needs to charge and discharge. Instead, it required a bit of detective work, which could be offputting some.

Using Command Prompt tools such as ping and curl, the APmeter was interrogated to understand how it communicated over the local network. There was plenty of back and forth with ChatGPT during this process, but once enough information about the device was available, it became relatively straightforward to build a working solution.

REST sensors were then created within Home Assistant to read the APmeter data locally.

From there, custom automations were built to control the system. The automation was set up so that Home Assistant continuously adjusts the EZHI output to keep the APmeter reading at the incoming supply as close to 0 W as possible. This means it discharges and charges to prevent import and export as best it can.

A second automation then charges the battery overnight on the cheap tarriff so that it is ready for use the following day.

The final result has been a fully automated AC coupled battery system that operates entirely through local control with complex data reporting and seamless integrations with our Home Assistant ecosystem.

Home assistant has allowed for complex visualisations and tracking of multiple inputs, a must for data nerds!

Early results have been fantastic. Compared to running the Hoymiles plug in solar installation on its own, electricity bills have fallen by around a further 60%. While that figure will naturally depend on household consumption, electricity tariffs and the time of year, it demonstrates just how much value can be unlocked by combining existing plug in solar with battery storage and intelligent automation. There is now the option of adding more solar for relatively cheap to further increase our production and returns.

Not for the faint hearted.

As impressed as the overall experience has been, it would not be fair to suggest the EZHI is perfect.

At the time of writing, documentation is one of its weakest areas. Much of the available information is either incomplete or difficult to find, information such as battery capability, how to integrate with Home Assistant and some of its more advanced features require lots of digging to find out, or the information on them is outdated.

Several questions could only be answered by searching through German forums, translating discussions and piecing together information from other early adopters. There is currently very little English language documentation covering more advanced installations or local integrations.

The EZHI would also benefit from more clarity on how the battery and the EZHI communicate, we know it is a CAN Bus communication system, and it appears to use a Pylontech Protocol but clarity and confirmation around this for compatability sake would be great. The AP Systems official compatability list is somewhat outdated already, as battery manufacturers are releasing new models such as the Pylontech C series, which it isn't clear if they are compatabile. Confirmation of the exact protocol being used to communicate plays into the EZHIs biggest strength: Its versatility.

That is likely to improve as more people begin using the system, but anyone buying one today should be prepared to do a little researching, of which we hope we will be able to help with our own pioneering guides!

Final Thoughts

Despite those shortcomings on documentation , the APsystems EZHI has been an extremely positive experience so far.

Its biggest strengths are how capable it is, the endless possiblities for expansion and development, and the technical challenge of opening up some of its more advanced capabilities such as Home Assistant automation. We love how it isn't locking users into a single battery ecosystem, bringing in more competition and better prices for us as consumers.

For DIY enthusiasts and Home Assistant users in particular, that flexibility is arguably its greatest selling point and AP Systems should really lean in to that as the Plug-in solar scene rapidly grows and is legalised around the world.

While there is certainly room for improvement in documentation and software support, the hardware itself has shown a great deal of promise. Its clear they have a very unique product which has lots of interoperatability and flexibility for users, offering much better value than other brands which are bringing plug-in storage options to the market.

To thrive, AP Systems needs to play to these strengths, responding to community demands, making sure the platform is open, documentation is clear and users have more certainity to their projects, so that they can build full energy systems which they can expand over time as they . The UK has a strong DIY ethos, a nation of shed tinkerers and have-a-go engineers for whom something like this is ideal. The EZHI is the perfect product to appeal to this spirit, and we look forward to seeing it fully on the market here soon.