Need help with getting start in solar

Good day everyone,

I am completely new here and to solar and was advised to pick some brains here regarding backup power and ultimately full house solar system.

My situation is a little complicated (at least for me) but I will try make it as clear as possible.

So I originally wanted a backup system for when Eskom decides to not do it’s thing to power 2 “offices” that come to about 700w at load for a loadshedding duration. I was looking at the following Ups, Inverters and Powerbank :: Inverters With Batteries :: Mecer 2400VA Inverter + 2x 100AH Battery (8 HOUR BATTERY LIFE) KIT - 1440W but apparently that is not a good idea and was suggested to start aiming towards going solar and scaling up as funds become available.

This issue is that the house was bought more then 35 years ago and the electrics are a complete mess, pretty sure they will be illegal and I need someone who is able to help me plan how I go from this mess to ultimately having a house that mainly runs off solar (with an immediate solution for the 2 offices while we build towards the end goal).

Any suggestions would be greatly appreciated and if someone could recommend someone to maybe come out and give us a quote then that would be fantastic.

I live in Cape Town, Fish Hoek so recommendations for this area would be greatly appreciated.

Thanks in advance,

Hi Luc,
Please provide more detail about what needs to be kept running in your 2 offices…

Welcome Supaman. I was in Houtbaai yesterday, if you posted this yesterday, I could have driven over the mountain to do a quick assessment.

There is a lot of knowledgeable people on this forum and I am sure a few of them will start asking questions soon.

Thanks for the welcome Jaco,

I unfortunately was only suggested this on another forum today otherwise I would have come sooner.

You reputation precedes you so it is quite unfortunate that I missed the opportunity.

I look forward to any help that I can get.

It seems like a “where to start” problem.
Usually, once you have a plan it all becomes clearer.
Break the problem down into broad parts or phases. Nothing too detailed just a bit of a plan.
Then you can prioritize the stages according to budget and needs.

Can I suggest something like:
Stage 1: Fix the wiring in the 2 offices and put them on their own DB, (bypassed from the main house DB).
Stage 2: Fit small solar for them. ( with a transfer switch between the main house DB).
Stage 3: Fix the remainder of the house wiring.
Stage 4: Expand solar to later requirements.

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Hi Richard,

Um I will try but I don’t know the power draw of everything.

I am looking for a loadshedding solution for 2 office setups that run at about 700watts in total.

  • computers
  • monitors
  • wifi
  • lights
  • small speaker system
  • potentially a tv

I basically need it to last a loadshedding duration so 2-3 hours.

I doubt the draw will always be 700w but that is what I got at max load with a meter someone gave me to put between the walloutlet and the 2 multiplugs with everything in.

The one pc is a gaming/rendering setup and the other is a simple office pc.

I hope this answers your question otherwise helps you understand a little better.

Hi Phil,

This is a fantastic suggestion.

It is a “where to start” problem in conjuntion with a “need an immediate solution” problem.

I am basically at the point where I am just biting the bullet and buying the Mecer unit I linked above because of a review saying it worked for them with a similar rendering PC + other stuff, I know this isn’t the best option and should be avoided but I need to start somewhere and we lose money everytime loadshedding pops up so we are basically throwing money away if we do nothing anyway.

Your suggestion would be amazing if it is possible and it would give me a lil room to breathe, trying to understand this all from scratch and run my own business is becoming quite taxing.

Those Mecer inverters are not the worst things in the world… though given the amount of room at the bottom of this spectrum, don’t take this as a compliment either :slight_smile:

The only trouble with them is that they are designed to take two 100Ah lead acid batteries, and you can do just about whatever you want, those things just don’t last.

I don’t suppose you can just run a generator? This is probably a surprising suggestion, coming from me and all… but that’s an immediate solution, cheap, effective, and those suitcase generators are always useful and easy to sell later. Small 24V inverters slightly less so (outside of load-shedding blocks where others also need immediate solutions).

Then take the time to measure and plan properly.

It’s amazing how people get paralysed by power outages. I used to believe that you could ask the question of which electrical device they missed the most but they appear so overwhelmed so that a sensible answer is not possible.This, then doesn’t provide a good starting point!

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I completely agree with what you are saying, even while being one of those people.

I think it is also coupled with the fact that I have grown up my whole life with kinda a motto that I don’t fiddle with plumbing or electrics as they can lead to absolute disasters.

So it basically leaves me with zero hands on knowledge about what is going on but a need to so others can help, couple that with trying to run 2 small businesses and it leads to a bit of panic.

This could be an option as well,

I will look into them as I haven’t considered them.

Do they use battery systems or is it basically like a normal generater and also are they safe for running PCs?

I wrote that last night, but this morning I did check prices quickly. The thing is, those trolley-inverters (with the Mecer on top and space for two 100Ah batteries below) cost around 8.5k to 10k, excluding the batteries. Add in two good batteries and you are not far off a really nice inverter-generator, such as this one (I’ve seen this model for around 13k at a Builders Warehouse).

Takealot has cheaper options too, like this and this smaller 1200W model.

Now make no mistake, generator power is expensive (somewhere between R7 and R20 per kWh, depending on factors such as Petrol vs Diesel, engine load, etc), but if you need something right now to drive a few PCs, that small 1200W model does not look too bad.

Then you get your portable battery pack inverter type things like the Ecoflow or the Flexopower. Generally lower power (Flexopower is around 400W max), but quite good enough for a few lights, powering a TV, or a few laptops. A bit on the low side for heavy things like laser printers (that you may have in an office). What is nice about these types of devices, is that if you are into camping… they work really well for that too.

Look up Bluetti. I have no idea what budget you are on but if your goal is a backup then a generator may be cheap but is a bit clumsy. I would not go a generator unless I was fully off grid. For off grid a generator will get you through does winter cloudy days if you don’t have enough solar panels and big enough storage. You don’t want to be mucking around with liquid fuels unless you have to.At least when off grid you will be able to schedule when your generator is fuelled, maintained and started. As a backup you will have to go outside and star up your generator which you will have to keep fuelled all the time. You know what happens to petrol lawn movers when you leave the fuel in the tank, they eventually gum up the carburettor and you can’t start them.

The Ecoflow and Flexopower are very similar devices. I see the Bluetti entry level model (similar in power capability to the Flexo) is 430USD… but somehow jumps double that price once local sellers get hold of it…

As long as you can get the power and time out of these other units, sure go for it. Bluetti that has done the rounds on YouTube reviewers channels have a fair capacity and power availability. Just make sure you compare apples with apples.

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The Flexopower Lithium555 has a 555Wh battery (rather specific… :stuck_out_tongue: ) and a 400W inverter. So good for a little over an hour at full power. The entry-level Bluetti has a 500Wh pack and a 300W inverter. They are pretty close as far as I can see. The Lithium555 retails for just under 9k… which is what I would expect the Bluetti to go for as well… but the two local sellers want quite a bit more.

I was thinking more along the lines of a 2000 Wh 2000 W. If you have to start up anything with a motor in it you will need a few amps to get it started. Once turning over they drop back to lower currents. You maybe closer to the mark with just a couple of pc. A bit limited but if that is all you want 400 W may be enough.

Andy on the Off Grid Garage had a look at the 2kWh one and now uses it as an additional battery bank to hold things over while he reconfigures his bigger battery bank and inverter.

It is true that inductive loads have an inrush current of say 6x its normal draw, but inverters typically also have an overcurrent allowance for say 1-10 seconds or so. So you can check that on the inverter you intend to buy. In other words, you don’t need to size the continuous load of the inverter for the instantaneous inrush current of your inductive loads.

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Indeed, most of them can handle 200% Pnominal for about a second. So given that an induction motor needs about 500% of its nominal power to start, the inverter needs to be 5/2 (about 2.5 times) the size of the motor. So 2000W probably is safer. But then… I’ve personally used an 850W well point pump off a 1.6kVA Multiplus without problems, so there does appear to be some leeway, some unknowns in the normal rule-of-thumb calculations.

And also, once you’ve decided you need 2000W… I’d just shoot for a 3kVA. In value for money terms, it’s the better one. It is by far the most popular product in the blue stable and benefits from economies of scale.

Edit: I’ve also started my 1.2kW swimming pool pump off my 3kVA. It caused an almighty startup drone, but it worked. Just this morning I started my 1.1kW air compressor off the same Multi.

We’ve just bought 3x Ecoflow River UPS (288 Wh + optional 2nd batt) for staff outside of CT (ie. stage 4 is really stage 4) and I have a Delta purchased earlier. They’re truly plug & play.

Both the River and the Delta can recharge from 0 to 80% in 1h and up to 100% in 2h tops, then run down during LS and does it again. For running work stuff during stage 2+, recharge time is essential. Everything else I looked at was on the range of 6-8h, which is fine for TVs and lights, but useless for work-from-home.

They’re expensive though, but should hold quite a bit of second-hand value if you want to upgrade to a fixed install.

(BTW, for me and wife the Delta runs a Dell PC, Mac Mini, PC laptop, 4x screens, 10 Unifi cameras + Dream Machine router, alarm & HTPC for about 4h. For the 6-8 AM slot it powers wife’s dressing table lights, hair dryer & unidentified hair heat thing. And says it could do so for about 30m all in before the computers start up. Youtube videos show microwaves running.)