The Deye micro inverter has been around a while now and has been a big part of the ” plug in solar” for a while and also can be installed in difficult places, We have been running it on and off over the year and lets have a re take on our experience.
If you would like to view our First impressions click here. Well will start with the problems..
We sold a few of the Deye Micro inverters and the popular choice was the advanced kit. If you read the initial post it would make sense why clients went down this route, though it was not without problems. oddly most of what we mentioned in the initial post.
We made a follow up post in respect of the installation and set up of the micro inverter due to clients having issues with the simple tasks, Deye Micro Inverter Setup. — RenewSolar
The manual shows the plug for the BY01 connection which can be wired backwards if you do not read the markings on the actual plug itself.
The second issue was the software and actually setting up the inverters. the issue here is “the logger” and to-date that is still the same. The relay is factory connected to the inverter, but its easy to connect this to the wireless. the problem being that this does NOT connect to the wireless and if you do, it will cause the system to not work.
The connection installation is a little confusing, but its actually simple, you need to understand what’s going on. so you have a inverter SN and a Wifi SN and you add the wifi NOT the inverter on the second request, the first request being your home network.
( I think that the explanation is harder to follow, but thats what it is actually like)
The inverter or rather the software got an update in the form of the “deye cloud” app which is far better than Solarmon software which caused more issues that it needed to. It was complex and we stopped selling the inverters due to the problems people were having.
You have to take into account that there is a small margin and when problems take a lot of time, its not worth it for us to spend hours undertaking support.
The good points
They work and we had the predicted performance from the Deye micro inverter.
We had the panels ground mounted and had changed the angle of the panel for summer sun and they worked. what we did notice was the current was higher (SC) while the voltage was a little down (27-29v) which was mainly due to the heat on the panels. the power was more like 750 watts as a result of the hardware limitations. The system worked the same as our summer GTI, and the power delivery was above or just below and even higher as you would expect.
What I did notice this year was solar production was down. This was not an issue with Deye’s micro inverter, but the sun; as both systems were effected by the lack of sun power. What should have been a daily yield of 6.1kwh was around 4.6 -5.2kwh. This averages around £1.00 per day yields in terms of ROI.
This of course does not effect our targets of around 1 year return on solar investment. The cost of the inverter dropped mid season as Deye made the G4 version of the micro inverter. The update was to connect the relay (M1) to the inverter body. If you had been following there was a problem which lead to the relay and thus this was updated to be connected rather than having to be attached to the frame where there is a small length of cable to do so.
Over coming issues
From a business point selling inverters is fairly simple, but giving advice can have legal implications. Therefore we have been a little cautious on what we are saying or writing to clients. We posted up the BS7671 and the electrical installation requirements as well as hardware solutions and some guidance. we also wrote that you cannot plug in, plug in solar.
I think this was off putting as we had a lot of messages from people who had been abroad and seen Plug in solar and wanted it for themselves.
The advanced kit came with a isolator RCBO and cable so that the inverter could be installed legally, but we also added a gen port. and made this post
We had one issue where someone had wiring issues, but we cannot wire the unit up for you for many reasons.
We don’t know how you are installing or where you are installing and we also come into another range of legal requirements and costs – yes there is a lot more work and costs required.
We obviously had the software problem which was resolved fairly quickly by Deye.
We had tried the Hoysmile inverters as they appear to be popular, but we had so much of a issue with the supply chain that we could not get stock of the inverters and this was entirely pointless and a complete waste of time. We also found out from other solar partners that they had also had problems with supply and support. This securing the brand as a No go.
Ecoflow came out with there plug in system which goes to their battery packs and for a long time I was not sure this was a good option that we would recommend. They are illegal and without the battery and other hardware these can be a problem device – I have not looked into details of these, but the battery failure and the fire risks as well as the costs, it may not be a great option.
We do not like grid tied and here is why
Grid tied is pretty much a simple process, but its wasteful and limited. If you installed grid tied, you don’t have a battery to store power for later use. from what you do produce you only save money if you are using the power, or its going back to the grid freely for others to make money from you.
if you have a grid tied and to make it work for you, you would need to have a AC coupled system. This means that there is an inverter charger connected to your home and it detects the exported energy, then it charges the battery with that export. Later when you want power it discharges the battery, or works as a buffer when a cloud passes. For some this can present a issue as you have to add the inverter power together, so a 800w micro inverter, with a 3.2kw AC coupled inverter would jump you to a rather more complex G90 application. G98 is more simple and can be filed after the fact rather than permission stage of a G99 application.
While this is a little bit of faff, you also have double conversion losses, converting solar DC to AC only to then convert the export AC hack to DC and to use the inverter, back from the DC to the AC.
That’s about 20% losses each time making the system in effective over other hardware ( Hybrid inverters).
What is the use case of micro inverters?
Micro inverters do not scale well in terms of cost, but they do offer flexibility.
Enphase is considered the world’s leading micro inverter manufacturer, but the yield has been limited by their hardware. NEP were the first to make micro inverters which actually provided the power from the growing power from the solar panels.
As you can see on the image above, the micro inverter works well where there are different array directions and this can offset the power production over the day or year. Most larger home inverter chargers ( AIO), have only 2 solar inputs, meaning that you are limited to just two arrays.
With micro inverters you can limit to 5 arrays on a single bus, but you would not be limited on how many bus cables you had.
Shading.
Micro inverters have the best solution of shading. Each PV input is a MPPT, meaning that all panels are independent and ran at the maximum. Therefore you could have a part shaded system that has different parts shaded at different times. This is different to strings that may have a larger array. but most modern solar panels are not badly effected by shade and it is where Tigo seems to offer a solution, one we found does not work, but they did come up with a lot of excuses that are implausible.
Small scale
For small scale solar, Micro inverters are going to be ideal, if you have the 800w its two panels, if you have 1200 its four. this means that you can angle the panels as you please to give you the best coverage for year round solar production. this would be of course the benefit from the independent MPPT inputs.
With low start up voltage the whole system is less in terms of panels and inverter costs, as the inverter also fits under the panels there is a smaller foot print for the entire installation, and they can be put anywhere giving you more flexibility.
ROI
The return is so much faster with the lower cost hardware. They do not scale well regardless of the lower cost, as you may find a bigger single inverter may work better and cost less. As you add micro inverters the costs can grow quickly which is not the same as adding panels to a string inverter.
it is worth noting that the life time of a micro inverter is normally less than its larger counterpart.
Boost for winter
Micro solar can also be installed on Victron and Deye/Sunsynk inverter aux ports. this allows you to add additional solar array to your home where you need a winter boost. Remember you could attach a normal CC to the battery direct and to the panels rather than the AC connection.
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