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Advice please: Wanting to start with a small solar setup with no battery


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My solar experience is limited to solar garden lamps, so I need some serious help, please!

I'm fortunate enough to in process of buying a house, so finances are a bit tight. My plan is to reduce my electricity bill, by trying to utilize as much solar power as possible (i.e. try to run the house off solar during the day, or get to it as close as possible, weather permitting), and then obviously at night it would be Eskom... for now. I want to increase the number of panels over time and then when I have the optimum solar input, start adding batteries 

I've read that first thing is to try and get the electricity bill down to <600kWh per month, to try and stay out of the last sliding scale bracket. In my current house I'm at around 1000kWh...

I know that I have to get an hybrid inverter and I think a 5kW that can be run parallel seems like the best option. But which brand and model? Axpert / Mecer / RCT seems to be popular to start with, but then they are sold to get something else. Then I also see that Growatt is being used, but from what I've read reliability might be hit-and-miss...

Next would be panels. I know I would like to go monocrystalline and probably >400w and I've seen brands like Canadian and JA. But is mono and >400w the correct route? And what brands would be ideal to go for? Keep in mind that I want to expand over time, therefor availability and compatibility is key. And what is the minimum panels I can start with (from what I've read they work in pairs).

Can this work? Can anybody please help me with some pointers and ideas?

Thanks!

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You say that you want to expand, learn from my mistakes and buy a proper hybrid inverter to start with, I would recommend the 5 kw Sunsynk, this inverter can be paralleled for extra capacity ( a lot of guys on the forum have this inverter), you can start with 4 panels, poly or mono , go with the cheapest cost per watt, but try to go at least 400 plus watts per panel, if you don’t need load shedding back up, the Sunsynk can run with no batteries

Edited by Tariq
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+1 on Sunsynk 5kW, using one here and its working well.

As for monocrsytaline, if you're lacking space, yes, go for highest yield W/m^2, but if space is not that limited, go for maximum smoke/R, in other words, probably Polycrystaline where ZAR/W is the lowest, I went for 280W JA Solar Poly's last year, they gave me most bang for buck at the time, again working well.

If I were you, I'd add 5kW's worth of panels, that would get you producing near the inverters limit when the sun is at the most ideal angle and therefore help make a dent in your Eskom usage, if you're not using LED lights as yet, budget on changing lighting... figure out where your energy is disappearing to and investigate options etc.

I used to run an Apple Mac Pro, still have it, but it gets switched on once every 2 weeks for a few hours, no more on for 24/7 etc. these things are total power drains, I've got a MacBookPro also and this is now my main machine, on 24/7 and slurping 30Wh on avg. as opposed to the bigger machines 200Wh+, there are other things that we've changed to reduce the power footprint, you really need to start measuring to see where the electrons disappear to... we used to consume around 900kWh/month, now we're more like 500kWh/month...

 

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Thanks @Tariq & @Kalahari Meerkat for the advice and recommendations!

As soon as I relocate, all the light bulbs (a mixture of CFL and normal globes) will be changed to LED, same as what I've done in my current house.

I think one of my big power sucking culprits would be my media server (basically an entry level gaming pc that's on 24/7). I'll have to look into this...

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45 minutes ago, DannyBoyZA said:

I think one of my big power sucking culprits would be my media server (basically an entry level gaming pc that's on 24/7). I'll have to look into this...

Good luck on that one, I was also not really wanting to "downgrade" so to speak, but when you potentially need more than a 5kWh LiFePO4 just for the Intel based hardware, then financial implications turn on a huge red light :-).

I also, btw, run 3 Raspberry Pi's, a 3B and 2 4B's total consumption should be well less than 50W and really probably only 20W or so mostly, one is running primarily Asterisk (VoIP PBX) under Slackware ARM current, the 3B is acting as PiHole server and also querying an environmental sensor or two around the property on 430MHz and logs the data to a SQL database and makes it available as graphs via the web server and the 3d one is more for seeing what else I can do, ideally getting the Sunsynk to give me my data locally rather than every 5, 6 or 8 minutes by way of some website in China...

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1 hour ago, DannyBoyZA said:

Thanks @Tariq & @Kalahari Meerkat for the advice and recommendations!

As soon as I relocate, all the light bulbs (a mixture of CFL and normal globes) will be changed to LED, same as what I've done in my current house.

I think one of my big power sucking culprits would be my media server (basically an entry level gaming pc that's on 24/7). I'll have to look into this...

You can try removing the graphics card, these are notoriously power hungry, rather use processor's onboard graphics or downgrade to a smaller entry-level card, and then fiddling with the power save settings. Best to replace with a smaller machine though, I use a 8th gen HP Microsever 24/7, it uses 50W (max when starting up) and then settles down to a trickle. despite having 4x 4TB drives, It also doubles as a Unifi controller and Pi-hole runs in a container. Second-hand ones are cheapish and pretty common on Carbonite.

I also replaced my desktop-based firewall with one of these, works great and runs a full UTM. Next on my optimisation list is my 16 port switch, will keep my eyes open for an energy efficient one that supports PoE. 

+1 for 5.5k Sunsynk, love mine, works great.

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21 hours ago, DannyBoyZA said:

I've read that first thing is to try and get the electricity bill down to <600kWh per month, to try and stay out of the last sliding scale bracket. In my current house I'm at around 1000kWh...

Well, if you get your PV system up and running then that will reduce the amount you draw from the grid. To maximise the benefit you will need to "move" loads into the daylight hours as much as possible and be willing to align your lifestyle with the system IE literally make hay while the sun shines. So no more running the dishwasher overnight, run that sucker whilst the sun is up. etc.

Personally I think 1000 kw/h a month is pretty high. I was only doing about 400 a month before I converted to solar. But one way of looking at that is my savings aren't so great. 

But if you see yourself adding batteries in the future then get those loads down. The lower the loads, the longer your batteries will provide power.  

A little discipline can go a long way here. Don't have things on that you don't need on. If nobody's watching the telly then turn it off etc. Don't fill the kettle all the way to the top and then boil it 6 times to make a single cup of coffee. Don't heat your water so hot that you have to add lots of cold. Geysers especially need taming.

21 hours ago, DannyBoyZA said:

I know that I have to get an hybrid inverter and I think a 5kW that can be run parallel seems like the best option. But which brand and model? Axpert / Mecer / RCT seems to be popular to start with, but then they are sold to get something else. Then I also see that Growatt is being used, but from what I've read reliability might be hit-and-miss...

Sunsynk or Goodwe. Those are nice all in one box systems that you can hook batteries up to in the future without too much trouble. They also come with tools that allow you to monitor the system so you can see when power is being used and when it's being generated. 

Bear in mind that 5kw limit. It's not an issue for you at first because without batteries when the grid goes down your system will go down. But when you have batteries that 5kw limit is what you can back up using the batteries. It's unlikely you will be able to back up the whole property, so you will have to split your DB into essential (backed up) and non-essential loads. Your geysers, electric stove, pool pump will usually go onto the non-essential side. 

If you can afford an 8kw unit then that gives you more that you an back up in the future.

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