Just have a think, ICE cars EVs and power generation

Yep. He doesn’t have to go looking for a charge station and then pay charge station rates and wait charge station time. So if you’re going to, say, Lisbon on a business trip then you and the City get what they want. And in some cities you’ll get into areas that you couldn’t with a petrol car.

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Cheapest one yet: BMW i3 eDrive for sale in Bloemfontein - ID: 27452205 - AutoTrader

Exactly the same spec is mine/ours, but with about 50 000km more on the odo, which is probably the reason for the low price.

Looks like a stick is needed to get EVs to take off. I’m sure this will happen but presently it seems that it’s the survival of the fittest.

Or a tax refund for the purchaser. It’s like so many things to do with reducing the global carbon foot print - it costs money.

I’m fairly sure that by now my heat pump has saved me money V a conventional geyser. But I bought it 13 years ago, and I had to pay up front in order to save in the long run. Not everybody is in that position (I’m no longer in that position).

Talking of heatpumps, governments in Europe are keen on these, but they’re not taking off as hoped. Firstly because folks are saying “yes, a heat pump is very efficient, but if you want me to install one how much of the cost are you going to bear because they’re not cheap.” Secondly, in the UK anyway, the boiler industry is running a disinformation campaign about heat pumps.

Of course there will be regulations passed such that all new constructions must use heat pumps instead of boilers or resistive element geysers, but those changes will not have a large effect in the short term.

With heat pumps with a COP 5 rating the payback is pretty quick. I wasn’t aware just how quick. Some finance firm should sell a package to the home owners and there’s sure to be enough in it to make it worth their while…

I had to go and google that. So if I understand correctly, it means that it uses 1W to produce the equivalent of 5W of useful heating. Assuming no losses in a 3kW geyser, your heatpump is going to run at 600W.

So that’s pretty efficient. Especially if, as I can, you can run it on a timer because there’s just two of you with fairly fixed routines so I can run it on a timer.

This fits in with what @plonkster was getting at elsewhere. It’s the whole package that really has a significant effect. You start getting heat pumps into the system and so they use less juice. You also work on the heat retention of the geyser and there’s another saving because if the water retains more heat, you don’t have to heat it as much as often. Then to complete the package, you have lots of non-carbon electricity to power that not so hard working heat pump.

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Indeed, even the older heat pumps have a CoP of at least 3.5 and mine runs at around 900W.

The same goes for the old “the grid cannot handle all the new vehicle charging” objection. That objection assumes that absolutely nothing else will change. In reality, the UK grid has not quite used up the room created when switching to LED lighting and as you add heat pumps to the list, this becomes even more true.

Further to that, people often forget that electrical systems are designed with a certain load factor in mind, basically the percentage difference between the max load and the average load. Residential supplies have to be designed with quite a bit of room, for that evening peak. That means that the capacity for charging vehicles after hours, when the load is down anyway, is already available.

Of course it has to be said that in South Africa, that doesn’t help if the supply isn’t available on the other side, but at least in terms of infrastructure, the grid is not as far behind as the naysayers want you to believe. That argument almost always assumes that nothing else is going to chance (or is already changing).

So true! If you can refrain from buying a system until you have improved your energy usage by more efficient devices and heat retention as much as you can then you will be able to see the benefits of your RE system. Otherwise you can’t establish what the actual benefit of this or that is leaving you confused :confused:

To run at a COP of 5, you have to lower the temperature delta. So unless it’s VERY hot outside, the heatpumps that claim COP of 5 is usually for home heating, running at less than 35°C.

Pool heatpumps claim COP of up to 9, but only under certain conditions - like the ambient temperature has to be 7°C higher than the water temperature.


There is an issue. We have the situation of infra not being upgraded. So the infra people is using the peak capacity as the average, so no need to upgrade the transformer, there is capacity spare in there. Same as with Eskom, keep on reducing the accepted % to cover failures (15%) down to currently less than or around 5%.

We see and read about that frequently. A new suburb development added to existing supply capacity, but upstream nothing changes, until it runs out.

In an ideal World, this is done correctly. We long since abandoned that philosophy, as evidence shows. So the “it should be ok or it should work this way” breaks down here. All bets are off. Maybe in the WC or rather CT it may be like that still, or at least somewhat, elsewhere, not so much me thinks.

Lots of things are a-changing, but sadly in the wrong way.


In many poorly managed South African municipalities… absolutely. Adding EVs to the mix is going to bring the rot to the surface very quickly. I am referring more to the world wide argument that the grid was not designed to handle this. Frankly… it was designed to handle higher peaks (even if not maintained always). The anti-EV bunch are absolutely speaking through their necks (I think that is an Afrikaans expression, Jy praat deur jou nek, ie nonsense).

In Cape Winelands on the 10th of April?

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I like the idea of an EV. I’m retiring, and have an amount of money that is burning a hole in my pocket, and I would so love an EV. But how to charge? It will impose an extra load on my battery overnight (I bet it wants more than 10kWh, which is the entirety of my battery). I could probably trickle charge it off solar during the day (5kW limit), but how do I stop it carrying on charging into the night?

Fast charging seems out of the equation for me.

HEV? Well I like those too. They are not as non-polluting as an EV, but they will reduce my emissions and have cool features that my old banger doesn’t have. And I don’t have to plug it in.

But the mileage I do these days, the planet friendliest thing to do might be just to hold on to the banger and at least not increase my footprint by the manufacture of yet another new car.

City of Johannesburg are offering a TOU tariff with quite decent savings in the wee hours. But you’d have to bet on the grid being available during those hours, and I don’t think that’s a bet I’d place.

Node Red to the rescue:


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You’d need an EVSE that has the ability to set a schedule, or some similar feature. Or use a sonoff or similar to just switch the thing on and off :slight_smile:

On the topic of nomenclature, I love how that has developed. When charging from AC, or so called “destination charging”, the charger is actually in the car. The box on the wall is just a glorified power socket with some safety features and signalling capabilities. Hence it is called an EVSE (electrical vehicle supply equipment). The entire location where this is installed is the EVCS, the electrical vehicle charge station.

That’s putting the DC directly into the battery. You can get away with as little as 25kW. When DC charging, the charger is outside the vehicle, and the charger itself is significantly more expensive. Dala (the dude who reverse engineered stuff for the Nissan Leaf) got one for himself.

I have been thinking about that. You basically have BMS comms with the car’s battery:


All the comms are closed protocols, but from what I have seen, there is no minimum current limit (and even if there is, many cars will just accept it if you tell them you are charging at that limit).

So, basically just need panels + MPPT + comms interface between car and MPPT…

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Aaah yes, the Optimal Energy Joule. It was built in PE too.