Ahmet Oguz Akyuz

Hi there! I have two Layen's style beehives, which I built mostly by following the instructions at https://horizontalhive.com/. This was the second winter for one of the hives, and it was the first one for the other. At the end of October, I thought I was winterizing my hives by putting several layers of fabric on top of the frames including clean undershirts and towels. In one of the hives, I even put a small cushion. All of these materials were placed above the frames and underneath the lid. The lid has two side ventilations and the hive has a screened hole at the bottom to allow airflow. After collecting the honey and making sure to leave the bees a generous amount, I removed the empty frames and put an insulation board to tuck the bees in to one side of the hive (to the side where the entrance is). Finally, I reduced the size of the size of the entrance slit to prevent unnecessary heat loss.

When I arrived at the side today, I was faced with a catastrophe. All bees in both hives were dead. The fabrics in one of the hives were clearly wet. Perhaps rain found a way to get in it couldn't dry out. The top of the frames were all moldy. Even the left-over honey looked quite dark and unusable. The second hive appeared to be dry, but nonetheless the bees were all dead.

Now, a number of things could have gone wrong of course including some kind of infestation. But I was wondering if it was a mistake to use fabric as an insulation. I wonder if it got wet because of rain finding a way in or because of the condensation from within the hive. I would be very happy to hear your advice on this matter -- in particular whether I was doing something bad for the bees in an attempt to keep them warm.

As an extra information, I want to keep bees naturally by providing them good conditions and leaving generous amounts of honey for their consumption, which they make for themselves anyways. I don't want to feed sugar or spray any kind of chemicals. I am not in it for profit, but simply for the joy of keeping bees. My climate is a continental one, with relatively cold winters (can go below 0 degrees Celcius but daytime temperatures are usually around 0-10 degrees Celcius in winter).

As a related question, how can I clean the hive and the frames which got moldy? I hope I don't have to throw them away and start anew -- especially for the hive. My frames are also custom build as the hive dimensions are non-standard. Looking forward to your advice.

Oguz

Hi David,

I am using Lithium (LiFePO4 to be specific) at 48V. The battery box has a BMS in it and I can monitor the individual cells (there are 16 of them) using an app. But the inverter has no communication with the BMS -- it is an hybrid inverter rated at 6.2 kW. So I think my inverter is already relying on the global battery voltage readings from the poles of the battery. Is this a problem?

If I add a second charge controller, which in the mean-time I realized to be quite an expensive option, it would also connect to the battery poles directly and would sample the battery voltage from there. But I will make sure to enter the same battery settings for the existing inverter and the new MPPT.

I do have a question regarding the MPPT choice. Given that my panel specs are 320W-410W 32V-40V 7.7A-10A and I will connect 6 of these in series, can you recommend me a budget-friendly MPPT that will work with them. Victron models are unfortunately very expensive.

Also, I noticed that inverters can consume non-negligible battery capacity at night. The aforementioned 6.2 kW inverter easily eats up around 15% of my 100 Ah battery. Do you know if charge controllers also consume such capacity?

Thanks.

Hi Nathanael,

Yes, the inverter is an all-in-one type inverter which includes MPPT. I do not see this MPPT but it must be inside the inverter box.  The description of the inverter states "Mppt 90-500v Pv Input 100a" , which I understand to contain an MPPT with the given specs.

If I now buy a second MPPT with the same voltage and current settings (I guess it doesn't have to be the same, but it must match my panel specs) AND program the MPPT to use the same charging parameters as the built-in MPPT that comes with the inverter, I should be good to go, right?

The only thing that I do not understand is that, the inverter would be unaware of this second MPPT. But I guess it is not a problem.

Thanks,
Oguz

Hi There,

In my setup, I two two strings of panels on east and west side of my roof. Each string has 6 approximately 400W panels serially connected. I would like to ensure that each string gets its own MPPT for optimal performance. I have previously found out that when I directly connected these strings in parallel, I ran into a malfunction in one of the strings (most likely bypass diodes in the strings). So I now want to do things right to avoid a similar future problem.

The issue is that my solar hybrid inverter has a single MPPT module. How can I best add the second MPPT to my system? It seems to be suggested that the second MPPT output should be directly connected to the battery. Doesn't it create a weird configuration where one string goes to an inverter and then to a battery and the other string directly goes to the battery (I mean after the MPPT). I guess if I make this connection, the inverter would be fully unaware of my second string which goes to the battery directly. Wouldn't it cause a problem?

Or would you suggest that using blocking diodes in a combiner box a better option for my system?

Thanks for any insights.

Thanks for your responses. After going through them and doing a lot of research online, I believe I have reached a reasonable conclusion. Let me share it here -- but the confirmation will have to wait until I bring down and hopefully inspect the junction box of the panels in about a months time (this is a remote site that I do not have regular access).

To remind you my setup, I had two strings (meaning serially connected) of panes on each side of the roof; east and west. The groups of panels were bought at different times, so the east side must have had a slightly higher voltage ratings (the panels look a bit bigger too). I made the mistake of connecting each string in parallel to each other, assuming that this is the best type of connection under such an east-west configuration. The solar guys from whom I bought the panels and help me install them did not warn me of any potential problem.

After doing research, I now realize that such an east-west configuration typically requires an extra step: 1) Either blocking diodes that prevents voltage discharge between the strings (each string gets its blocking diode in series, before the strings are paralleled). 2) Separate MPPT for each string. These two solutions are clearly presented in this video: https://www.youtube.com/watch?v=-x_6OLdAods

I will ask a related question about these two options in a separate thread.

So I now hope that lack of either solution caused a heating and a malfunction, most likely a short circuit, of the bypass diodes in the failed string. Hopefully, my junction boxes are not buried in epoxy and have easy to replace bypass diodes. Will keep you updated once I fully get to the bottom of this problem.

Yes, I disconnected west panels one by one. Sorry for the typo.

The brand of the inverter is Lexron - it has a 6.2 kW rating and a MPPT voltage range of 90 - 500 Volt. I think my inverter was turned off when I arrived at the site from the on-off switch.

Dear Fellows,

I've run into a strange solar panel problem, I would like to pick your brains to hopefully figure out what could be going wrong.

First my setup: due to east-west facing of our home, we installed 6 solar panels on the east part of the roof and 6 on the west. 6 panels on each side (let's call this a set) are serially connected to each other. The two sets are connected in parallel. The panels are approximately 500 W each. I bought the west facing ones a few years earlier, but they are not older than 5 years old. We do have a 6.8 kW inverter and 5kWh lithuim-ion battery. The system was working when I last saw it.

When I arrived our off-grid home a couple of days ago, I noticed that the inverter is reporting 0 volts from the PV during the day -- which was unusual. I disconnected the plus and minus solar cables from the inverter and directly measured the voltage using a voltmeter and I saw 0 again. The next day I climbed the roof to further inspect the issue. I discovered that the six panels on the east side are actually producing good voltage (something close to 200 V, which was reasonable given the position of the sun). But 0 was coming from the west side. I then disconnected all the east panels one by one and individually measured their voltages. 0 on all of them (one reported something like 4V but it is much lower than what it should be).

Talking to a few solar people in our town (not necessarily knowledgeable about the matter -- but they are in this business anyway), one suggested that the east side panels could have burned out the west side ones, especially if I left the system alone without any load. His argument was that when the east side panels produce more volts in the morning than the west side ones, they can burn out the west ones. Could this really be true? Isn't the purpose of parallel connections between the sets to deal with such situations. And this system worked like this for approximately 2 years -- why choose now to burn them out?

In any case, if there is a burn out, I would assume one of the diodes or panels to burn out first potentially protecting the rest in the series kind of acting like a circuit breaker. This could be wrong thinking, I know. Unfortunately, our roof has a steep slope and it is impossible for me to look at the back of the panels to check the diodes. I would have to bring them down, but this is a multi-people job that I cannot afford to do it right now.

To provide a few more clues, this was an unusually wet, rainy, and stormy winter around our off-grid home. Perhaps water got into some places that it shouldn't have? Does the fact that parallel connecting the working and non-working ones made the combined voltage 0 suggests that there is a short circuit somewhere? Do you think just leaving the system dry out and hoping for the best could bring my panels back?

Sorry for the detailed post, but I am miserable and clue to this mystery would be very welcome!

Hi There,

I would assume that in a post and beam foundation, the beams should sit on top of the posts for better load bearing ability. But in some builds, I see that beams are nailed to the posts. Here is a youtube link   to a builder who I am sure knows his stuff, but he is nailing (see the part between 2:30 and 3:00). Is it because the total weight the beams will carry is not that much so that nailing works? If you were to build one from scratch, would you recommend the beams to sit on the posts rather than being nailed to them. I can see one advantage of nailing the beams, which is that they get tightly attached to the posts. If we were to put the beams on the posts, we can still do it but may require some L-shaped braces or diagonal screws.

Thanks for any insight.

Thank you very much for the detailed replies. Part of the problem is that this garden is located miles away from where we normally live (8 hour drive by car). So I can't always be on top of the weeding chores. Also the garden was rototilled several times by a nearby farmer, and later on by myself. This definitely made the problem worse. The soil is quite sandy, which easily compacts and gets very hard in the dry season. The region has Mediterranean climate, which means no rain roughly between May through October. So the garden is irrigated with drip irrigation.

I really think that deep garden beds is going to be the answer. I am thinking of stacking three 2x4's along the length of the beds as border (about 25 meters = 75 feet). This is not going to be cheap for sure, but maybe I can think of a cheaper border alternative. Please let me know if you have better ideas to make the borders for the deep bed. Could borderless be an option? Then of course I need to add good quality soil and mulch. I also thought that if I had softer soil pulling this weed could be much easier.

Unfortunately my garden is infested with this pesky weed (please see the video https://drive.google.com/file/d/1Do_c4A1-4NWuU-B3MJdi1L7O13GvV8Xz/view?usp=drive_link). I think it could be called witch grass or couch grass -- not exactly sure but it is some kind of nasty grass. You can see the video of me attacking it with a hoe. I want to get rid of this weed or reduce its impact on the garden by natural means. I am trying to grow vegetables on that spot and the presence of this weed makes it a pain. Some people say that it can only be killed by spraying with a chemical but I do not want to do that. Any advice is most welcome.