Louisvdw

What are the reasoning why you would use the higher voltage MTTP against a cheaper one and do the reasons justify the price. I'm looking at this from the point of view of someone just wanting to start into solar, trying to reduce the monthly electricity bill, without breaking the bank. This is just looking at the solar part. Lets assume ESS with 48V battery and Multi. If I look at the cheapest option for each voltage we have: MPPT100/20-48V (max 1160W) @ ~R2500 MPPT 150/35 (max 2000W) @ ~R5000 MPPT 250/60 (max 3440W) @ ~R10000 Before your panels can start charging the batteries, the voltage need to be more that the battery voltage. With only 2 panels (series) in the 100V MPPT, the 3 panels under 150V and 5 under 250V will start sooner. But how much difference does this make in practice? Will the wire cost make that much a difference to offset the cost if you need to do 4 panels (2s2p vs 4s)? Any features that the 100/20 might not have that could limit your system? Would the 150/35 (2000W @ R5000) be better or same vs. 2x 100/20 (2320W @ R5000 - having 2x MPPT trackers might be better also)

GeyserWise has a PV geyser system availabe for a while now. https://www.geyserwise.com/products/pv-water-heating-systems/150l-pv-water-heating-system/ If you compare this to a normal PV system where you want to run your electrical stuff on solar, then I would react with the same response. But the idea here is that you don't use a thermal solar geyser to heat your water. So think of those PV panels replacing the thermal panels (Flat of vacuum tube, etc.) The benefit here is that you can upgrade an existing geyser system to solar with much less cost and with more safety. Safety - A normal thermal system can overheat or even freeze. These systems recycle warm water into the panels when they get too cold. If they get to hot the system can blow up (not sure how they handle that these days). With the PV panels this is not much of an issue. It is an electrical switch to limit the heat and PV panels dont have that same issue when water freeze as there are no water in them, thus they handle cold better. Installation - You can use you existing geyser installation. No extra plumbing needed. Just an sparky that fits the solar panels, MPPT and new heating element to the geyser. This about half the installation cost for an upgrade to solar geyser vs thermal. In interest is that there is a youtube video on the early "beta" version of the GeyserWise PV system. In this version they charge your battery after the geyser has reached it's temperature. But it does not seem that this has made it into the production version.

Many 220V LED floodlights also use 32V inside. I would have though 36V made mode sense.

I would suggest the Inverter forum https://powerforum.co.za/forum/9-inverters/

The Mecer is also an Axpert, so they are very similar. The Axpert is not in the approved inverter list to feed back into the grid, so you might have a problem there in future. From what I understand the Axpert also have a hard switch over if you need more power than it's max. So if you use for instance use 5.5 kw (more than the 5kw max of the inverter) it will switch the full load to the utilities. If you use something like the Vicron Multi it will just add the extra you need from the grid and supply the rest itself (0.5kw from the grid and 5kw from the inverter)

Most LED projectors are small and use a built in battery so that that they can be portable. To charge the battery will be similar to changing a cellphone although the battery will be larger and thus take a bit longer. But this should not have any real impact on an existing solar installation and usage. The be more accurate you will need to look at the power rating (LED projects should be in the range of 10-50W). For an hour usage at 50W you will use 50Wh. Your notebook will normally be between 50W - 120W. PS. The big thing to watch out for with these LED projectors are their resolution they work with (480 x 320 is poor while 800 x 480 is better) and the brightness (200 lumens you need a dark room, 800 lumens is not bad).

I think part of the problem with gas is to get efficient heat transfer. Last year I got one of those gas stoves that have build in fins for better heat transfer and it made a huge difference. You can see the fins at the botton of the pot in the the image at https://www.loot.co.za/product/xtreme-living-inferno-cooking-system/tkhg-5447-g000 Most gas geysers would have a similar concept as well.

You could make a UPS that use an automatic changeover switch which switch to the inverter as soon as the grid fails. This is more efficient that in the inline method described by PJJ, but will cost more and you need a fast switch so that appliances will not loose power during the change over. Victron sell these (Filax 2), but they are expensive so it is better just to go with a Multi. More detail on the transfer switch and wiring https://www.electricaltechnology.org/2018/11/automatic-manual-changeover-transfer-switch.html

If this is for a normal Pi it all depends on what you installed on your Pi and if it has a UI or if you need to connect using SSH. If however you are using your Pi with Victron VenusOS then just load VictronConnect to you phone connected on the same Wifi as the Pi and you should see the Pi there. It has a link to the log in age.

Sorry, I don't have any spare

@Energy I got mine from Netram R120 for the basic https://www.netram.co.za/3008-sonoff-basic-wifi-wireless-smart-switch.html But Pishop also has some stock https://www.pishop.co.za/