superdiy

Version 1.10 available from: http://www.ostrovni-elektrarny.cz/index.php?page=podpora

OK, I've now looked again at the image you've posted - I thought it was SolarPower on your PC, but now I saw that it is a screenshot with a manual in the background.

Don't you have the option to change this drop-down to "Grid-tie with backup (II)"?

Hi jcn, have you tried to upgrade SolarPower to a later version? I think the latest is 1.10. My inverter is a 2014 model with firmware 3.10 and 0.31 - you have 0.32 which, to me, looks like a later version than what I have. I was able to adjust the settings you refer to from the initial version of SolarPower, which was bundled with the inverter and in all the versions of SolarPower thereafter. I would suggest to try a later version of SolarPower and report back. Yes, the software does query the inverter's capabilities and it also looks at the FW2 value in quite a few places, but it only checks FW2 > 0.3 or FW2 <= 0.3 - I'm not sure what the difference between FW version 0.31 and FW version 0.32 would be, but both of those versions will have the same result in either the FW2 > 0.3 or FW2 <= 0.3 comparisons.

OK, that makes sense.

One thing that bothers me (being a perfectionist) about this picture is the arrows pointing towards the suns?

Hi Haider, welcome to the forum. Inverter settings are not one size fits all - you have to configure the inverter for your specific needs. If you can give us more information about your set-up and requirements, e.g. PV panel specs, number of panels, off-grid, grid-tied, feedback to grid etc. etc. we might be able to make a few suggestions. Regarding charging settings, again you'll have to send us more detail, preferably a link to the datasheet of the cells you are using.

OK, totally different story. You can then feed the gas geyser directly since you already have storage.

That was not an official calculation, but depending on the length of cable used you can run either 4mm2 or 6mm2 per string of panels producing in the range of 8-9 amps - again not calculated exactly. 3 strings in parallel will require 3 x the cable cross-section of the cable used per string and you always go a size up instead of down when you use cable, because the thicker the cable the lower the resistance, losses, heat etc. etc. If you are using 4mm2 per string, for 3 strings you would use 12mm2 or the next size up which would be 16mm2. (or 3 x 4mm2 cables in parallel - your choice) If you are using 6mm2 per string, for 3 strings you would use 18mm2 or the next size up which would be 25mm2. (or 3 x 6mm2 cables in parallel - your choice) If 25mm2 is the next size up then be it. In these low PV voltage configurations you will have a lot of current flowing from the panel array and especially if using long cable lengths, you rather want to use thicker cable.

OK, saw more detail in some of your other posts as well. It has features of both the Axperts and infinis.

Keep in mind that the collector only holds 1 or 2 litres of water depending on the type and size. If you feed the gas geyser directly from the collector, without having storage, you will use the hot water from the collector within the first few seconds while you shower. Or do you have a solar collector with an integrated storage tank at the top?

Yes, that is correct. Electrically it would not really make a difference where you install the combiner box. If in the "battery room" you would have to run say 3 pairs of 6mm2 cable between the 3 strings of panels and the combiner box. If you put the combiner box closer to the panels you would have to run thicker cables with the same cross section of copper as the 3 x 6mm2 cables, e.g. 18mm2 cable between the combiner box and the charge controller / inverter. So it is your choice: 3 pairs of 6mm2 cable or one pair of 18mm2 cable. 18mm2 cable is not standard and you might have to use the next size up e.g. 25mm2 - keep in mind that the thicker cable is more difficult to work with e.g. when pulling through conduit. On the other hand if your combiner box is in the "battery room" it is protected from the elements and easy to monitor / replace a blown fuse etc. etc. If I were you I would run 3 pairs of cable to the "battery room" and install the combiner box in the battery room.

Hi Jaco Please give us more info about your inverter - the 4KW infini? On the 3KW infini there is a setting in the software where you can adjust the feedback calibration - if I remember correctly Wetkit fiddled that value until the meter stopped tripping. But I would really like to know more about the 4KW infini.

My pleasure. That's what this is all about - to help out others.

1st two will both work, 3rd one will not get hot water from the "collection box" back into the "holding tank" because the hot water will not flow down into the top of the "holding tank" - that simply means that the "holding tank's" water will never be heated by the "collection box". The input "from street" into the "holding tank" should also be at the bottom of the tank, not at the top. Like hot air, hot water rises and you have to keep that in mind when you route the piping and when you mount the solar collector and where the water enters and exits the "tank" / geyser.

A charge controller cannot distinguish between different power sources. Depending on the SOC of the battery the charge controller might sometimes draw very little power from the laptop PSU and on other instances it will draw a lot. Since it is a switch-mode power supply it will always try to keep the voltage constant, irrelevant of the amount of power being drawn from it. If the charge controller draws more power from the laptop PSU than what the PSU can handle (overload condition) or if the PSU is running at almost max output for extended periods it will eventually fail. You will not have the same problem with a PV panel, because the panel will only be able to supply a certain amount of current and once you try to draw more than that the panel's voltage will start to drop (unlike the switch-mode power supply which will try to keep the voltage constant) and that is usually when the "maximum power point" (MPP) is reached. If the charge controller tries to draw more current the panel voltage will drop further and the charge controller will back off and draw less, the panel voltage will rise again and the charge controller will draw more current again, which will cause the panel voltage to drop again and the charge controller will back off again and that process will carry on and on and on without causing any harm to the panel.

The inverter / charge controller needs to be able to charge the battery bank at a recommended minimum current of 10% of the Ah rating of the batteries. In your case all the inverters are linked and each inverter can charge at up to 120A (60A solar and 60A grid) which gives a total charging current of 600A. That means that you can effectively have a battery bank of up to 6000Ah in your installation. Currently you have a 1040Ah (4 x 260) battery bank, so effectively you can almost add 80 more batteries. Ideally you do not want any parallel battery strings because of the dangers if one or more cells in any of the batteries fail and becomes shorted and because of the complexity of balancing and monitoring and the challenge of having exactly the same length of cable per string in order to ensure that each string is charged and discharged equally. Having said this I would not recommend adding any more of these batteries in parallel to the existing 4 strings. If you do want to increase the capacity, I would suggest to rather sell the 16 Omnipower batteries and replace them with one string of 2V cells with a higher Ah rating.

Ditto 2 controllers charging the same bank - not recommended. Even if you can adjust both controllers to change charge modes at specific voltages etc. etc. no 2 charge controllers will be calibrated to the millivolt and or milliamp and at some point in time they will fight. It is a different story when charge controllers or inverters can be linked as in the case of the Axperts where they have a shared battery bank and communication between the inverters.

In most PV panels the individual cells are all connected in one serial string. When manufacturers assemble different sized (e.g. 150W & 300W) panels they usually make use of cells with similar characteristics, but use more of these cells in larger panels (e.g. 300W) and less cells in smaller panels (e.g. 150W). Since the cells are all connected in series the open circuit voltage and max power point voltage of the larger panels will be higher than that of the smaller panels, but the short-circuit current and max power point current will be exactly the same in both panels. Therefor if you buy a 150W panel and a 300W panel from the same supplier and the datasheets of both panels indicate the same short-circuit current and max power point current, you can be fairly certain that they've used cells with similar characteristics in both panels. That 150W panel and 300W panel connected in series will perform exactly the same as one 450W panel using similar cells. If you however connect a 150W panel and a 300W panel in series and they consist of dissimilar cells e.g. where the panel voltages are the same, you will have a very mismatched combination. To summarise: When connecting panels in series ensure that the max power point current (IMPP) of all the panels are as close as possible to each other When connecting panels in parallel ensure that the max power point voltage (VMPP) of all the panels are as close as possible to each other When you have to connect panels in series and parallel e.g. 4 parallel strings of 3 panels each, the IMPP of all the panels in a string must be as close as possible to each other and the combined VMPP of each string must be as close as possible to the combined VMPP of every other string.

Yes, do get those, but as I've said, if it comes from the same manufacturer and the same cells are used to manufacture the 2 panel sizes, the panels voltage is the only thing that would be different since the properties of the individual cells are exactly the same. It will work perfectly if the same cells are used in the 300W and in the 200W panels and if the charge controller can handle the higher voltage. Think of it this way - a 300W panel and a 200W panel made up of exactly the same cells are nothing else than if you are using 3 x AA Energizer Max batteries connected in series and the set connected in series with another set of 2 x AA Energizer Max batteries connected in series. The batteries are exactly the same, the current through them will be exactly the same and the set of 2 x AA Energizer Max batteries connected in series will have 2/3 available power compared to the set of 3 x AA Energizer Max batteries connected in series. I don't know how else to explain it.

Usually most companies make use of exactly the same cells when constructing panels of different sizes - larger panels consists of more cells all connected in one series string and smaller panels consists of less cells also all connected in one series string. By adding more cells in series the total voltage of the panel increases but the current stays the same. In your post above you claim the voltage to be the same and the current to be different between the different sized panels - are you 100% sure this is the case? If the panel voltages of the 200W and 300W panels are indeed the same, then you can connect the strings in parallel without any issues, but if the voltages do differ I stand by my suggestion above (3 strings of 300W+300W+200W+200W) if your charge controller would be able to handle the higher voltages.

Usually solar panels consists of a specific number of individual cells all connected in series - the more cells connected in series the higher the power rating (and voltage) of the panel. If you are going to use panels manufactured by the same company the cells used in the panels should have very similar characteristics. I am leaning towards the idea of maybe having 3 strings in total with 2 x 300W panels and 2 x 200W panels connected in series, per string. Then you will have 3 equally rated strings in parallel and the MPPT will be happy, but it all depends on if you are willing to re-wire the exiting panels and if the charge controller would be able to handle the higher array voltage - so please answer the following: Will you be able to re-wire the current panels differently? What is the maximum PV input voltage on your charge controller? What is the MPPT range of the charge controller? What are the open circuit voltages of the existing and new panels (or model number or link to the datasheet) What are the MPP voltages of the existing and new panels (or model number or link to the datasheet)

Although that might be true, by software I'm actually referring to monitoring software e.g. on a PC.

OK, that is on the battery side only - I have not really monitored battery charging/discharging that closely on the infini - changes in PV reflects instantly on mains power though.

I might be wrong - I have not tested this since I do not have one, but that was mentioned by other users in this and other forums. The infini 3KW draws about 60W from grid during the night though.