mgoedeke

So how would one spread ones bet for that rainy day? Say a 4x200 A.h LA battery and 2x3000C? I have the Olson BPS 2436 or Mecer also has some inverters in my power demand range... One can always power the geyser (we have 2 in series) with the remaining energy with spare capacity which would chop a significant amount off our monthly bill. Would one have to program a micro to do that or is that the realm of the fancy inverters (where one would spend 50% of the battery capacity on) Unfortunately we're on PAYG. I hear that even some very fancy inverters can trip them? I'll look at the options, seems like 3000C goes for R16k which seems like good value. ANy suggestions for LA?

For for the Li-Ion batteries, which is currently the benchmark for W.h/R at rated discharge? How does that compare to Lead Acid if one draws at 0.15 -0.2C for example to 50% DoD? A good inverter is about the cost of a 3-5 kW.h LiIon battery bank it seems like. More batteries and panels might trump the fancy inverters for this? For my low baseload power requirement, what are the recommended options around the 2-3 kVA mark among the Axpert and co crowd and what among the hybrid inverters of the world?

5 hours changes the setup quite drastically. Then it makes sense to limit capex and use some grid power and find some point where one can optimize the cost of the inverter with regards to the solar panels and battery bank. It also means that efficiencies become more critical.

Awesome responses. I'll post some questions below for tl;dr. I can mount this setup about 5m away from the panels and will run only this application and perhaps rewire my 220V LED lights to it for lighting in the house. Because of the continuous load this might see RoE in 3 years perhaps. I am looking at various options. I have an existing new in box Olson BPS-2436 24V inverter and a battery box with dead batteries from an old UPS that can house a good couple of LA batteries. To add a solar charge module to that would mean a MPPT and some panels. Because I have a 98-99% PF load I can look at VA simply and if one takes out the money for lithium batteries one might want to optimize the efficiencies right to the PC power supplies and cooling fans. The average load will be on the order of 790VA though if I upgrade it might go up to 1kVA. If the better inverters have 3-5 kVA capacity and solar charge controllers built in that would make a move easier but i suspect most ROI gains will be with solar and batteries. I have an existing 25u rack mount chassis standing around that I could use for Li batteries and the like and looked at the Pylontech 3000C batteries with some hybrid inverters as an option. I am looking primarily at cost per drawable kW.hr and don't care for 1.0C over 0.5C that much. A quick search on the forum suggested the 3000C, i'll look into the others listed here. Because of the continuous base load and >R2/kWh Tshwane electricity ripoff I suspect that the money is best spent in some moderate solar and some hefty batteries. i assume 8 hours charge and 16 hours discharge for one would need 3x base load in solar panels at 2.4kW? perhaps one can start at something smaller and grow? It seems like the money is best spent on LiION and solar capacity here. Questions How can I estimate solar irradiance and panel output in Pretoria? Can one get anything for the old 100/200Ah batteries when buying some AGMs or similar? Do the hybrid inverters have any benefits during periods where solar irradiance drops below my base load? Please suggest good sources for LA/Lithium batteries and panels around Pretoria/Gauteng. Regards Martin

Hi All I want to keep some video surveillance and processing gear hooked up 24/7. Base load is about 700W with ancillary peaks at some 1kVA-1.5kVA max, though it could be capped at 1kVA. I would like to have the system to be able to survive an outage for up 4-6 hours, obviously during the daytime a solar setup would help and because the base load is fairly constant +/- 100VA the solar panels seem to make sense. Any suggestions? Hybrid MPPT inverter and battery/BMS or all in one hybrid inverter? I was thinking whether one 5kW Pylontech battery or similar would be a good starting point though lead acid would likely also work, just be a lot heavier. The kit will be about 5-10m from the panels in an attic with a concrete slab floor, masonry walls, one large window for ventilation and a polycarb roof. Regards Martin