On Tuesday the 12th of November 2013 we've had 12 UPT Solar panels installed onto our house. In total they're good for an electricity production of 3250 Watts at its peak. Positioned straight at the south they have an estimated delivery of around 3000 kWh per year. The panels have been bought at and the installation has been done by MetDeZon B.V..

Electrical wiring

The UPT Solar panels are connected to an Omnik 2.0 and an Omnik 1.5 converter. These take care of the transformation from the direct current (DC) to the alternating current (AC) which is used on the main electricity network. There are a lot of discussions on going how solar panels should be connected to your home eletricity network. I have used a Gacia electronic breaker switch with a C characteristic on 16 Amps for both of them which I purchased through Vekto.nl. The official guidelines in The Netherlands (the NEN norm) states that you don't have to use a ground fault circuit breaker (aardlekschakelaar in Dutch) when connecting solar panel converters as long as the group doesn't contain any other devices and does not contain any electronic outlets. This means that the solar converter needs to be connected directly to the mains and not through an electronic outlet and a plug. My personal all time favorite is to use Wago connectors. Even though most solar converters will be connected this way, some still vow to put in a ground fault breaker switch anyway. I guess in the end its up to you or your electronic installer which approach to take.

Installation of the solar panels

This is the part I have been doubting for a long time for: doing it myself or having it done. I've been looking at many movies and reading many stories about doing it yourself and it seemed like it was terribly easy to do so. Especially compared to the price they charge for having it done. Still, I didn't want to run the risk to climb up on the roof and slip causing injuries when falling down or worse. That wouldn't be worth it, so that eventually pulled me over the line to go and have them installed.

It turned out to be an easy job at hand indeed. All you basically need to do is push the roof tiles up a little and slide a metalic slider over the wooden carriers that support the roof. After having done that, you slide the roof tile back in its place again and continue with the next one. You place these like a meter away from each other and in two rows above each other. Once done, you use a saw to get the carriers in the proper length and then simply push then into the holders you just attached to your roof. The next step is to carry the solar panels up on the ladder to your roof. These guys are obviously very experiended in doing that and carry them one by one on their neck. Once up on the roof, you lay them over the two sliders and use simple screws to make sure they stay there. That's it. They could easily walk in the roof gutter to get the job done in about 1,5 hours for 8 solar panels with 2 guys working on it.

The four panels on our backyard shed were of course even more easy as they could simply walk on it to lay them out. All in all it took them about 3 hours between arrival and departure to place 12 solar panels. Next time I would certainly do it myself.

Installation of the converters

Once all is ready to go, the Omnik converters will boot and will be ready for use. They automatically become Wifi hotspots themselves. As you can see on the screenshot on the left, they show up as AP_ followed by an unique number. They are unsecure access points to which anybody in the viccinity can connect. Add to that the fact that once connected, you get a DHCP lease from the Omnik and the Omnik itself is always available under http://10.10.100.254 and uses the username\password combination admin\admin for authentication and you do want to change that configuration as soon as you can. And luckily you can. Once you're connected via your internet browser to the Omnik, you have the option Account in the left menu where you can change the username and password. Watch out here though. The password is only allowed to be 15 characters max. This is not shown anywhere nor is there a validation on the password fields if its longer than that, though when you do enter more than 15 characters, it will run against a bug after reboot where only each other HTTP request to the webserver in the Omnik will be accepted as shown on the Fiddler trace below. This makes the unit really unworkable as you keep getting password prompts. I'm in contact with Omnik support (really good and fast with replies!) to have this issue resolved. So just stay with 15 characters max in your new password and you should be fine.

 

 

 

Once you've got that taken care of, you can use the Wizard option in the left menu to go through a step by step installation process. It allows you to have the Omnik connect to your Wifi network through the same module you're now connected to it. Have it scan for Wifi networks, select your Wifi SSID, put in your encryption key and it will connect to your Wifi network. From there onwards, you can also connect to it through the IP address that your Wifi access point will assign to it so you don't have to connect to the funky unprotected Wifi anymore. From discussions on the internet I understand that with Wifi modules of which the serial number starts with (0)602, they would automatically disable the wifi access point broadcast once you link it to your own wifi as a client. With the (0)603 and (0)604 like I have, this doesn't happen and both the access point and client mode will stay active. I have contacted Omnik support about this and they've told they will built in an option to disable the wifi access point functionality from (0)605 onwards which is expected to be released sometime in January 2014. For now if you're using a 603 or 604, the best you can do is add a WPA-PSK2 password to it so not everybody in your neighbourhood can log on to it.

Live Monitoring

These Omniks are equipped with Wifi modules which are used by the Omnik to frequently send out statistical data to the host li504-69.members.linode.com [176.58.117.69] over TCP port 10004. It first sends out an ICMP echo request, better known as a ping, to see if it can reach this host. If the ping doesn't reply, it doesn't attempt to connect to this host. This data transmission can not be disabled on the Omnik. The only way to block it from sending data to Omnik would be to set up a firewall to block this traffic.

You can sign up for free at www.omnikportal.com where you can register your Omnik converters using the serial number that should have been given to you by the company that sold you the Omnik. This is the place where the statistical data the Omnik sends out is being transformed into some fancy statistics and charts. It also allows you to share this information with the whole wide world to see how good you are producing electricity and it also allows you to see others in the world who are producing electricity through Omnik converters. Direct links to my solar panels can be found on the right side of this page.

The Omnik also allows for configuring an own IP address and port number (up to two additional locations next to the one that is set to the above address and which can't be changed) to which the statistical data will be sent. This sounds like music to me wanting to parse the statistics myself in my already existing domotics system. Checking with Omnik support on the details of the protocol used by their software revealed that it the specifications are closed and they will not share it with the public. So we have to find it out ourselves.

Omnik Monitoring API

I have done some research into the protocol used by Omnik and have created an API in C# on the Microsoft .NET 4.5 framework which can be used to query and parse the statistics from the Omnik device. Thanks to these three great resources and some investigation myself I managed to create the most rich and full open source API yet available on the internet for the Omnik Solar Inverters. Find the source code below. The code is overly commented inline and contains a working sample console application, so for someone with some Microsoft .NET development skills it should be very easy to understand and implement in your own software. It supports both pulling data out an Omnik (actively connecting to it and requesting its statistics) as well as having the Omnik push data to us at an approximate 5 minute interval.

Note: the sourcecode is now also available at GitHub

Version 1.0 - released 19th of November 2013

KoenZomers.Omnik-v1.0.zip (source code in Visual Studio 2010/2012/2013 - 164 KB)

Changelog:

  • Initial version


 

No sun, no Omnik

No, this isn't meant as some cheap slogan for selling Omnik stuff. I was unpleasantly surprises when being in the middle of configuring the Omniks that I all of a sudden lost my connection. When walking up to both of the Omniks, I also noticed that the status screen didn't display anything anymore. Since it would be awkward that I messed them both up at the same time, I had my doubts whether or not they would work without electricity being generated or in other words, the sun shining. A quick call to MetDeZon revealed that this was the case, no sun, no Omnik. There's no way to access it without the sun shining. Hummm.. quite sucky. Keep that in mind when configuring your Omniks to avoid unpleasant surprises.

What's really the return on investment on solar panels?

This is the #1 question asked when mentioning you've got solar panels on your house. On the right side of this page you'll find links to the Omnik website where a live overview is being shown of the electricity production of my solar panels. Based on the API I have published above, I also created a SharePoint 2013 App which shows the produced electricity and money equivallent in one glance coming live from the solar panels (updated every 5 seconds):

The first two lines are a set of old solar panels (over 10 years old). The bottom two are the two Omniks which are mentioned on this page. The energy production of these two started on the 12th of November 2013. The ROI is calculated by taking the current production in euro, divide it by the number of days since they were placed and dividing the cost price of the solar panels by that outcome. That gives me a pretty accurate view on how many more of the similar days would be needed to get to the break even point on production versus cost price.

 Solar Panel Statistics