CoCT built a dam … maybe they want to extend that concept?
Doh. Completely forgot about that. Yeah, definitely could end up with something like that to cover the evenings for sure.
And then this just in: How much Eskom wants to charge normal households, and those with solar - Moneyweb
The core there, from what I’m reading with us being grid tied having registered for free and having a PAYG meter installed by CoCT for free because we are not feeding anything back and having to pay a fixed monthly fee already and knowing that we are using Eskom for peak loads and knowing how CoCT has structured the PV feedback if you do, this is the core of that article I’m reading, seeing as this is EXACTLY what is happening with us:
Eskom identified the need for a residential time-of-use tariff to provide the right economic signals that promote economic efficiency and sustainability for Eskom and the customer long ago.
The proposed tariff will also help to optmise the system and “protect future revenue”.
There is a need to get fair compensation for the use of the grid and to incentivise customers to stay connected to the grid but that the “current IBT structure does not provide a TOU signal or a signal for net billing; PV [solar photovoltaic], for example, reduces sales, but not peak consumption and peak demand.
How is this true? My peak reduced substantially. I can see that from the data. I think they are confusing Grid-tie inverters (those PV inverters) with hybrids/off-grid inverters. I am actually quite certain that is what they are doing in setting these regulations.
Hybrid systems (with sufficient battery backup and no feedback) should improve the stability of the grid. It is PV inverters that is horrible to grid stability. To me, the following two types of installations should be tightly governed:
- PV Inverters (because they do nothing but worsen the “duck graph”)
- UPSes (because they cause “loadshedding” to be less effective)
Hybrid (with no feedback) and offgrid inverters should really be applauded and encouraged. With hybrids, regulations should be made regarding a minimum battery capacity as well as a minimum discharge to be allowed, to smooth intermittent clouds etc. Otherwise hybrids will be just as bad as PV inverters for grid stability.
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It is definitely true. Even us people with Hybrids, we definitely try to use the PV as it comes in rather than cycle the batteries unnecessarily. That means that between 10AM and 3PM we’re buying no electricity, and then come 6PM we add to the normal peak along with everyone else.
Well, perhaps I’m not the worst offender in this regard. We do cook on gas and we have a heat pump for the hot water. But it is still true that between 6PM and 8PM… I’m running from the grid baby, even if my consumption is low.
On the other hand though, if you are one of those people who don’t add to the peak, then the TOU tariff will also not be a problem to you. And people like myself will move our loads, eg by giving the heat pump a timed profile so it runs after 10PM.
Not necessarily. Load-shedding is about lowering the peak consumption, not the overall energy use. If you think about a power vs time chart, with Watts on the Y axis and time on the X axis, the area under the chart is the energy while the line itself is the power. Load-shedding cuts off the peak. A UPS ensures that the area under the chart remains the same. It is in many ways no different than your fridge, freezer and geyser switching on directly after load-shedding to replace the lost energy, and also the reason why quite often load-shedding does not lower your power bill 
You will however get to a point, perhaps like it is in Zimbabwe now, where we also won’t have enough energy, so that load-shedding itself will no longer be enough, or there would be so much of it that you would literally not be able to recharge the UPS in that time. But we’re far away from that… at least for now.
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That’s one pet peeve I often have with people who say EVs cannot work, usually on social media. They would make claims that we can never have EVs because with load shedding etc Eskom already can’t keep everything on…
Well, the truth is a bit more complex than that. Around 3AM in the morning, Eskom has spare capacity. They’d love to sell some of it to you… but you are in your bed sound asleep!
The other argument is the perpetual “why are we still selling to Zimbabwe… CuT tHeM OfF!!1!”. #eyeroll. We sell them like < 1% of our energy, and that’s as part of the whole SAPP (Southern African Power Pool) deal whereby we also get power back (sometimes more than we export) from some of the other partners.
Don’t you just love how every social media commentator is an expert?
</rant mode off>
Not all of the Hybrid users will add to the peak demand. I am quite fortunate in having enough battery capacity, so that the only time I would use municipal electricity is when it is cloudy for a few days on end.
Currently, my 6PM to 6AM usage is all battery, with PV and battery during the day. Grid is only used as a last resort. Jaco actually installed a disconnect between my pre-paid meter and my house, so I can selectively “load shed” my municipal power.
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If we assume that everybody has a UPS (presumably regulations is written from that view point, otherwise no one should care about the 0.01% [made up number] of power users who have PV), then wouldn’t we just cut the peak off say the 8am to 10am slot and add it to the 10am to 12pm slot (when all the UPSes recharge) and worsen it even more, because the UPSes (depending on lithium/lead acid) will try to recharge in say 30 minutes all 2 hours worth of energy? So if everybody has a UPS, loadshedding should have no impact (or just pretty much kick the can down the road)?
I can see this being the case, but most people I know with hybrids, actually aren’t that tech savvy or can’t care to fine tune a system they had installed. They wanted a loadshedding solution that can pay for itself in the long run. They had it set by the installer and forget about it, drain the batteries as soon as PV drops out and by about 2am in the morning (depending on battery capacity) need to switch to Eskom. This is an almost perfect situation for Eskom.
But this is why I propose that the size of the inverter shouldn’t be regulated when it comes to hybrid (at least not so tightly), it should be the size of the battery bank.
Haha! I remember how everybody became a legal expert during the Oscar trial and then again a virologist at the start of COVID. Unfortunately the internet makes people think they are learned in every respect while in reality they are parroting what they read somewhere, written by another internet expert most of the time. I am not ignorant enough to exclude myself from that collection of people… 
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Yeah, that is true. My argument runs out of steam when you have both an inability to handle the peak AND an overall shortage of energy. Then whatever energy you conserve is simply added to the next window, as you say.
Still, I don’t think it is entirely symmetrical. The things with high peak consumption are usually not backed up, so you still get rid of them when you load-shed (and they still come back the moment the power is back, with or without a UPS). Also, there are regulations saying how hard you are allowed to charge (though presently this only applies to SSEG users who use a UPS as a hybrid SSEG, to use the Cape Town lingo… ie people with an Axpert/Mecer), which generally forces you to spread out the energy “reclamation” over a longer period, again helping bring the peak down even if it leaves the energy demand in the same place.
Ah yes, I understand. Effectively you are forcing some people in the country to shift their evening routine with two hours, smoothing your 6pm to 8pm peak, over 4pm to 10pm for example. Not sure if the effect would be worthwhile over the midday/after 10pm though.
Indeed, which I think is a little strange to say the least. Perhaps there’s difficulty enforcing regulation on UPSes, but since the large ones still require a CoC (because it’ll be integrated into your wiring), surely it can be regulated at the CoC stage?
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[quote=“Deon_in_ZA, post:28, topic:491”]
Not all of the Hybrid users will add to the peak demand. I am quite fortunate in having enough battery capacity, so that the only time I would use municipal electricity is when it is cloudy for a few days on end.
Exactly, from using just under 600 kWh, for March( with the cloudy/rainy days this month ) I am at 54.6 kWh usage, and now with the days getting shorter, using using around 1 to 2 kWh in the morning due to discharged batteries.
So I think @plonkster’s point less relates to total energy usage, but rather peak demand. But yeah, if you are saying that you are looking for 1/2 kWh in the morning due to flat batteries, it would probably be nice for Eskom to give you that power at 3/4am.
I’m one of those who specifically shifted my energy usage to consume grid over the peak period (6PM) because my battery capacity is not enough to get me through the night, and I wanted to have backup power available for as long as possible for unexpected outages.
If this every comes to pass in Tshwane I will likely just reverse this and use batteries over the peak (to avoid the high cost) and then consume Eskom in the early morning hours when the batteries are depleted. Of course, I won’t have backup power but if the costs are what they’re talking about here, I’ll probably take the risk (or invest in more batteries).
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@ebendl , I’m exactly the same. I want to reserve the battery power in case of an outage. I want the batteries to be full by 5PM (ish) and then I want to keep them as full as possible in case there is an outage later. Which is something that has happened a few times where I live (an outage at 11PM which lasts until 5AM for example).
So for a long time I did the reverse, I use power over the peak, and then from around 4AM I start to run from the batteries (to make space for the solar power that comes later). In other words, I make Eskom’s problems worse on both ends … 
If we get a TOU tariff, I will also just shift things around a bit. I’ll set the heat pump to not run at that time, and then use the top 20% of the battery to cover the loads. Something like that.
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Therein the HA doing the SOC increases every day, to get to 100% by 5pm.
Cause I know what the Critical Loads DB would need for extended hours, I drop the inverter max power (via a Cronjob) to the same wattage needed for extended Critical Loads on batts, which is a SOC of 30%, so that from ±8pm till when the sun takes over, I shave off even more from Eskom. And if there is a LS event at night, it matters none, as the numbers work out, adjusted according to seasons AND keeping an eye out for next days planned LS events AND weather.
As a result AND with the Daly gone, I can now do this - down to 44% for the year, yesterday being bad day for solar:
My weather view, 1 is for today and 2 the week.
Just in case you have missed this article:
Correct me if I’m wrong but this is the first time I have heard of Time Of Use (TOU) billing.
This makes sense since the problem that Eskom has is the peak demand on the grid hasn’t got any better with all the RE that has been installed. That is a real problem for them!
Hehehe I learned of this some years ago when we made Scheduled Charging for Victron systems. Precisely so it can charge during the cheap times, and discharge during peak times. People actually save enough money that way that it pays to use the batteries…
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I don’t think we have the capacity for TOU billing (the electricity meters need to be smart!)
So I reckon we aren’t in a position to implement this type of billing even if we wanted to…