Since getting our solar connected last week Tuesday, we have not has a moment of load shedding. It’s been a week of bad load shedding and bad weather and we’ve been going strong, and not a single moment without power. For our need the setup is perfect and honestly the way to go.
But, with the heavy rains of yesterday and today, I will experience load shedding for the first time today. It’s been impossible to charge the battery and there just isn’t enough sun to generate more power. But it’s perfectly acceptable, especially seeing as it is an exception rather than a rule.
So there are pros and cons to both. It comes down to what you need. My 8-panel 5kW inverter system generates about 12 to 15 kWh per day, which is about half of all our power needs on a normal day. The most important part would be the battery, and I would suggest looking at adding an additional battery to help carry your needs longer.
At peak, our home can go over 5 kW of power needed, but that is with the pool pump, geyser, oven and dishwasher all running at the same time. If you only get the 5 kW inverter option, as long as you keep a close eye on what elements you use, you should not have any issues at all.
I would say it comes down to your budget and your position about ownership. You can definitely add the cost onto your bond and own the system outright, but it adds a lot to your monthly bond. You could buy it outright if you have that money lying somewhere. For me, neither of those was an option looking at my budget, which is my the leasing option through GoSolr was the only option.
My recommendation would be, a 5 kW inverter should be perfectly fine for you, but I would recommend the additional battery.
@Solitude I can echo Hammer’ words. Our power requirements are a bit less with not having a pool so the 5KW inverter, 5,5KW battery and 8 panels covers most of our needs. Even with the load shedding at stage 5 we can avoid power outages when there’s enough sunlight. With the recent rainy weather it is a bit more challenging. Another, or bigger capacity battery would always be a win since most households use the majority of their daily power in the evenings so if anything that would be the area to spend a bit more in - it sucks that it is the most expensive area already though.
The different in price between the 5KW model and 8KW model of the inverter we have is fairly small comparatively, so it may be worth looking at 8KW inverters [Edit: okay I checked the difference is actually quite a lot more than I thought]. The most important thing is to get a smart hybrid inverter so that it seamlessly balances the load between solar/battery and grid power whenever the demand is higher than the inverter provides, i.e. no tripping unless there is load shedding and then you exceed the 5/8KW demand.
Check out https://solaradvice.co.za/ it’s a great site where you can put in your current municipal bill, indicate when you use the most power during the day and tweak a few other things. It will then present you with reasonable options that you could install as well as the pricing. It will give you a good idea of what would be good to get.
What is also possible to do is get just the inverter and battery to start off with and then add the panels later. So you’ll still be using grid power but will have a decent backup in place for load shedding. Then as you have the funds you can then get some panels installed.
Today is a good test for my solar system. It is completely overcast and has been raining constantly without break.
This whole morning, I’ve been drawing power from the batteries as the load exceeded the generation power but now I’m finally generating about 1.3kw and charging the batteries slowly (standing at 55%). Will see if generation increases closer to the afternoon.
The geysers aren’t doing too great though. Temperature is currently only 21 degrees so will have to turn it on manually later.
@Solitude With the inverters you have flexibility. If you buy 5kw, you could always buy another 5kw later. Depending on which on you buy, the 5kw might require some management (i.e. don’t run microwave and tumble dryer simultaneously). I would definitely recommend Sunsynk or Deye. They’re the same, but Sunsynk just have a more “westernized” interface from what I hear.
Solar panels you can always add later as you need them. It would obviously be useful to have a bunch to start off with in case you have loadshedding during the day. This would carry you through that and allow you to charge the batteries.
The bigger issue is the batteries. You need to buy them pretty much at the same time or very close to each other, otherwise the newest one will degrade to have the same life as the remaining life of the older ones.
Don’t know which brands you were looking at, but you can get Hubble AM2 5.5kw batteries for around R32k and I see there is Dyness 4.8kw for around R26k. I think Dyness is ok (they are 1C batteries), but I can’t remember. You’ll have to check for reviews and maybe on PowerForum for feedback. I have Hubble AM2s and no issues (ran them for a year in the old house before moving them over to the new house) and I’ve heard of people claiming from their warranty and they replace problem batteries without issue.
@DarthMol / @DieGrootHammer / any others: I’m trying to wrap my head around how the system works, so excuse some really dumb questions.
You both used Gosolr right? Any reason why you chose them over others? Are there even others who do the same thing?
Do you have to manually switch over to the solar system when loadshedding starts? Or is it automated?
If it’s manually, is it a DB board type of system where you get to turn off whichever circuits you don’t want to use on the solar system, and then manually switch over to it?
Also, if it’s that sort of manual system, how do you handle things like 2:00AM loadshedding sessions?
On the rare occasions that there is Eskom mains power, how does the system know whether to pull energy from the grid or from the batteries?
From the way you’ve been describing things, am I correct in assuming that the batteries only get charged when there’s sunlight? Is there no way to recharge them from the grid when there’s extended periods of overcast weather? (I realise that that sort of defeats the purpose and won’t do anything to reduce your Eskom usage, just curious if it’s possible to do in a pinch.)
If you reach the three-year minimum contract period and opt to buy the system outright, do they give you an idea now what it would cost? If so, broadly what sort of cost would it be, and how is that calculated? Percentage of outright cost to install now? Or based on the estimated cost/value of the installation in three years time?
And Darth perhaps more than Hammer as you’ve had your install for a little longer: have you seen a decent reduction in your Eskom bill since you’ve installed your system yet? Are you feeling the monthly fee is justified? If you had to completely ignore the obvious practical benefits of having power available with a lot more regularity, is it a positive financial decision? There’s no way I’d be able to afford an outright installation without extending the bond, so I’m trying to work out whether the added bond cost or the Gosolr rental would be the better option.
I’m sure there’s more I don’t understand, but I’m already feeling dumb just re-reading that lot, so I’ll leave it there for the moment.
Yeah with the rain I’ve got some major “range anxiety” for the batteries, but mainly know if probably experience load shedding at some time during today. Oh well first load shedding in a week so not too bad
Just had a look. The panels at work are producing 264W in these cloudy and raining conditions. Battery SOC is still 100% loadshedding kicked in here at 10:00.
So far so good. 2 hours into a 4 hours load shedding stint and the power is stable. Can keep my pc running even, but decided not too to charge the battery more. Even in this bad weather it is wild that the panels still keeps power going!
The system is always connected. The inverter is the brains that handles all of that. You can setup different profiles. Only charge from solar, use battery power between x hour to x hour, etc… They install a second DB board that becomes your essentials board, this is what you battery runs when there is no Eskom. So something like the pool pump and stove wouldn’t go on there. There should also be a CT coil before your meter that prevents you from exporting power, something my boss learned the hard way and actually doubled his bell.
You can also allow the grid to charge your batteries or only rely on solar. The grid actually charges the battery faster than solar. At the office when load shedding ended the battery was on 42% and the draw from the grid was 3kW.
The other questions I can’t answer. This is just osmotic stuff I’ve picked up at the office and the other guys with solar.
Another question to the solar guys, if you have the ability check your incoming voltage from the grid. My colleagues inverter stopped switch over back the the grid straight after loadshedding. It turns out the voltages are sometimes exceedingly high (280V) and his inverter is preventing switchover to prevent damage.
Okay let’s unpack some of the questions you have here from what I can:
I took them as I just spent all my savings in buying a house, and at the time my bond was way too new to add anything additionally to the bond. Because of those budgetary reasons, I was tempted by the leasing model and it made sense within my monthly expense budget.
It is not a manual system, so when power is cut by Eskom, the inverter automatically routes power from the batteries to the house.
The inverter constantly checks where power is coming from, and balances power from various sources to ensure the house has the power it needs. So if Eskom actually provides power, the system checks to see what the demand is, both from the battery levels and the house consumption, and balances the load accordingly.
The rule of thumb that GoSolr gave me was, panels power battery, battery powers house. But the inverter is smart enough to balance power from all sources. So I’ve seen extra power from the panels come directly into the house when the battery was charged to a specific level. I’ve also seen the batteries charge to a different level during the night when load shedding ends and the batteries are getting low. For example, I would get power from my panels when my battery is at 85%, and the panels will focus on battery charge when the battery is below 50%. At night, Eskom power (such as it is) would charge the battery if the battery was below 30%, and stop charging the battery when it reaches 50%.
They give you a full costing structure for the next 8 years, after which the payment needs to be recalculated by their boffins. The cost (which you can pay on the 3rd anniversary of your contract) depends on your setup, but is between R120k to R160k. From there it decreases according to their costing schedule. If you go and calculate things, it is more expensive going through the Gosolr route rather than getting a loan or additional bond for solar outright. But, the additional value add maintenance and monitoring they do are something to take into consideration. Plus what I am paying now monthly is less by 67% than a loan for the same level system.
While I cannot fully comment on it yet, what I have seen is that the number of units of power I had when my installation was completed lasted 2 as long as it did previously. I normally would go through about 160 units of power a week. When my installation was switched on, I had just under 200 units on my meter, and today I have 120 units of power left.
all the plugpoints linked to the inverter are constantly running on inverter power so when loadshedding hits everything powered by it is still on, because the inverter i have is only 3kw the plugs of the fridges and microwave are eskom powered, I did have a changeover switch installed incase the inverter fails then i can just flip it it bypasses the inverter and I run on eskom power for all the plugs. the only thing we couldnt install as the electrician was running out of time and i didnt wanna pay for an additional callout was an additional surge protector in the db board
Which installer if I may ask? I’ve considered a number of them to do my installation just recently, so I might know of them. (Then again, there are sooooo many)
