Solar PPAs in South Africa

Hey all.

Been a while.

Any of you’ll have advice on what questions to ask when looking at a Solar PPA option?

Looking to get it installed at a building where there’s no real budget to pay upfront at the moment.


I have a lot of advice, what would you like to know?

(I work for a company that does utility-scale PPAs and have tried in my own capacity to do the same for smaller industries[making sure no conflict of interest occurs!])



Good day Karel.

Had the team from Candi Solar out to do a site inspection. They will put together a couple of scenarios. Worried I don’t know enough to ask the proper questions.

Looking at the term. It’s 20 years. This seems long to be bound to a contract.

My other question is what should we look out for? Probably need a lawyer to read these contracts haha.


Too long in my opinion.

Have you considered a rent-to-own option instead? I know there are a few outfits around that will do a rent to own thing over 3 to 5 years. The ones I’ve seen are all Sunsynk installers, so it will probably depend on whether you have preferences in that department.

How does this look?

My first question would be why is option 1 not loadshedding proof in the sun :slight_smile: .

Other than that, the 15 year option 1 does not look to bad. What do you think?

Do you know what you need?
If you’re deciding between grid-tied and hybrid at this stage with this sort of budget it is likely you are going to get hurt.

The issue is the central heating of hot water. That takes a lot of power. I can get the amounts.

Can you explain what you mean by ‘going to get hurt’ :smiley: .

I mean financially, to a man, we have all paid school fees ( and they hurt).
The question you are asking is so fundamental to the system that it is clear that you don’t appreciate the enormity of this functional choice.
I suggest you get professional advice.
I am really not trying to sound patronising, but that is a lot of money to gamble because the wrong fit will be irrevocable.

Spot on! No I understand now. The wrong fit is what I was trying to avoid. Simply trying not to make a 15 year mistake.

I’ll start off with the aim, that’s to lower our power bill. In the BC we do not have the expertise to know where to start. Had a couple of companies over to give quotes. Been looking at a PPA because there’s no upfront cost options.

Some stats, the building consumption peak was in August at an average of 2300kwh/day. And a low of 900kwh/day in January.

Our heat pumps are hungry beasts! :slight_smile:

I support @Phil.g00 but in short… Option 1 will switch off during load shedding as it’s Pure Grid Tied (ie no battery backup). It’s designed that way.

Ah, thanks man! Much appreciated.

So you have to have a battery to run a hybrid inverter I take it? Could you not simply have a small battery to have the setup still work during daylight? Thanks.

Not really for a long list of reason I don’t really fully understand…
Start here for example: AC-coupling and the Factor 1.0 rule [Victron Energy]

That’s a lot.
Enough, in fact, to warrant a consultant.
A consultant’s first step will be to reduce that amount, and then he/she/they/xie/yo/ze/ve/co/en/ey will outline your solar requirements to suit your needs.

1 Like

As always, “It depends”. With a Low Frequency inverter, such as a Victron Quattro/Multiplus, the battery cannot be too small. The way it creates AC from the battery causes a ripple voltage on top of the DC, at 100Hz, and if the battery is too small then this ripple voltage is simply too large. No, TTT, I see you there with your virtual hand up… just no. :slight_smile:

With a high frequency topology, such as used in the new Multi RS, you can get away with as little as 50Ah (or 2.5kWh) of battery even though this is a 4.5kW (continuous) inverter. That is to say, with the HF setup, the battery can be 4 times smaller than with the LF setup.

You will run out super quick, and probably damage the batteries if you discharge them too fast, but you won’t have a ripple issue. You can, in fact, get away with just using a small battery, as long as the loads are kept in check.

1 Like

With that energy requirement (and IF cost reduction is your goal), you need many more panels than quoted and a grid-tied system. Probably 3x or 4x the panels.
(Which brings into question the space available for panels).
If it were me, I’d also have a more minor hybrid system that only ran the lights and finished the lift cycles.
So, as you can see, permutations may be more suitable.
The hot water system design (centralized vs decentralized) may be worth considering.
It’s worthwhile paying a consultant.

1 Like

Having put my hand down … during LS, would you want to power the big loads other than like i.e. computers, lights, internet?

Yes, then go “left”, get the consultant in.
No, then another rabbit hole … go grid tied (no batteries) with appropriate UPS’es to power selected loads, during LS, also an option. When LS is over, the grid-tied system will recharge the batteries via the UPS’es, so fewer batteries are needed.

Like others have said, put differently, a “rabbit hole” this … not to forget the NEEDS vs WANTS vs HOBBY level one has to consider.
(NEEDS are much cheaper than WANTS … HOBBY level is “priceless”)

Oh hat, I got this wrong. That’s the total consumption. Which is not what we are trying to cover.

Owners/tenants understand the struggle of LS. The aim is not to keep any units power on. It is to feed the hungry heat pumps when we can. They are 3 x 50kw. So the total we aiming at is 150kw. That’s why the proposed system is 100kw and 140kw.

Apologise for that confusion, answering in between work, my bad.


Hey TTT!

Got the total numbers wrong. My bad. As said above.

Would be a win to lower the ever increasing cost of Eishkom in the long run. The biggest user would be the heat pumps.

The lights to the common areas would be great to have on. Lights in those areas give the sense of safety.

No need to run the heat pumps during LS. Like I said, the struggle is understood :slight_smile: .

Wonder if that hybrid system needs such a massive battery?


And they run when Eskom is on only so then you need only a grid-tied system without batteries.

Such a system reduced your Eskom usage over the years to come.

And what is the total wattage of them on?
For lights you need batteries, being on at night, but because they are not really heat pump wattages, you can get away with a much smaller battery, hence the UPS idea, a pure sine wave one, cause I bet the lights are LED.

Note: These are just ideas we are spitballing, to give you more things to ponder on.

I’ll ask the building manager. Yes they were all converted to LED not too long ago.

Oh yeah for sure! Much appreciated.

Asked the consultant to redo a quote based on all this feedback, thanks all. Hard to think of cost saving and the future at the same time :smiley: !