The way forward

Not even sure this goes under general… But guess the admins will move it if they deem it necessary:-P

So a few of you know my journey of complaining and diagnosing and guessing…

Now the journey continues… Moving to a new house. This time round my approach of “essentials” is a bit more complicated as water supply is borehole to tanks to booster pumps to filtration system… Basically, my little mpii 3000 is likely not quite adequate anymore.

Would also love to do solar this time round…

So do I add another mpii in parallel? Find a buyer and get a bigger mpii? Or (this would make me sad) switch to a different brand!?

Also, does anyone have an installer that would be willing to re-use my existing kit, add to it and add me some panels, in the Randburg area? @JacoDeJongh if it’s blue and pylontech going forward this would be your flavour?

Also do I get an electrician to come split the db first?

And can anyone recommend a solar geyser installer? And tell me the nightmares to watch out for?

I would really recommend splitting… IMHO it is the easiest, (but still time-intensive) part of an install.

I would recommend skipping this step and going straight to a heatpump and a couple more PV panels. It’s just so much easier to control and maintain.

  1. I have move this thread and assume you will post the journey and photo as you go :wink:
  1. Sell and buy what your loads will require.
  2. This assumes a full assessment of your current and planned loads (heating, cooling, cooking, pool, etc)
  3. Then you know what inverter size you go for. Brand is a matter of choice.
  1. Jaco can answer this or maybe do they install.

See point 3. above… what do you split? Do 3. then 5. and then Split decisions can be made.

Heat pump per @_a_a_a with an oversized PV array.

A pricey option given that you still have to provide that extra power for it.
Stand alone solar water heating is a mature competitive industry these days.

Cannot agree less.

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Wasn’t my intention to be this controversial…

But anyways

I was planning on splitting anyway, did it myself on the current house and yes, took me a few hours. Worth it. The new house has sub DBs so it will be more work.

Regarding the solar geyser… There’s 4 options, I guess, but I can cut it down to 3 because gas would still require paying for. There’s the solar tubes option (I have friends and colleagues that have these and love them). The heat pump option… I have family and colleagues that use them… But not on solar… Mixed reviews but the level of control is attractive. And then there’s the panels with a mppt and DC element.

Option two has quite a bit of cost to it, I’d have to upsize the inverter, add panels and most likely another mppt and the actual heat pump. Would however love to see some numbers on these, summer vs winter and what automation people are doing.

Option 3 adds a lot of cost but none of the flexibility of option 2.

Option 1 is al about simplicity… Definitely doesn’t have the braai-brag factor. From what I can tell the big trick with these is to have the backup power to make sure the pump runs and then also to not oversize the collector… At the risk of limited hot water on cold days?

Can I suggest an Option 5: Dual Tubes and Element
I have an Extreme geyser with a 2000w element on my inverter (Sonoff Switch and HA to control)
It only is used if needed when the water temp is below 55deg.
I have it come on @ 12:30 till 15:00 and 5:00 to 6:00.
I also set a min SOC of 50% so it doesn’t drain the battery very low.

You get the best of both worlds. Tubes for 90% of the time and AC the rest. Plus no DC panels - all panels available for other things if needed. Like the dishwasher in the morning after 9:00.

I like it!

I presume mains power is available? So you would use this power and only use battery during outages?

Solar is available and used most of the day - then battery to 25%-40% SOC, depending on loadshedding schedules, at night… The mains only if needed. Pretty standard model.

My take on the standard model is: battery only if needed…

With lithium batteries now being standard, it is normal to cycle your batteries at least a bit.

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That is the “no loadshedding/outage plus feed in model”.
I bet it won’t work for you in South Africa…

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My 2 cents.

Had an EV tube system that needed total replacement after 9.5 years. Looked at flat panels, heat pumps, everything. The costs put me off.

In the end, a 2kw element on a Geyserwise timer with a couple more panels added to cover the 2kw load.

Heated water = a happy family.

Then our geyser popped last week, I left the 3kw element in. I will pay a few cents extra to heat it faster if there is insufficient solar.

The core takeaway is I’m not spending 10s of thousands on a device that saves me more money, that needs replacement every few years. That is not saving.

Busy with Shelly to trigger a 2P Hager NC relay to automate the geyser again as I have removed the Gyeserwise on it.

If you have it already then yes… otherwise normal geyser/element or heat pump… :wink:

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I called heat pump repairers. Did not like the answers I got given on their “general” lifespans. Some last for a very long time. Some don’t.

The costs did not make sense when you have spent the monies once and then have to keep on spending that to keep on “saving” … the replacement tends to happen at the worst time ito finances. Or just my bad luck …

This penny I shared becomes a real-life consideration when you need to replace a water-heating device that is EOL. 2kw element with “headroom” on the inverter to handle that with ease, enough panels to charge the batteries and run the inverters demand, is cheaper, my sums concluded.

EDIT 1: Hence me removing the Geyserwise’s also. LS tends to “weaken” them and at R1800 going rate now, bugger that expense. Back to basics with cheaper components.

EDIT 2: Also see insurers are getting “stricter” on LS claims.

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Mains only in emergencies??

I am very happy with my heat pump. It’s been going without a hitch for more than 6 years.
Heat pumps are so plentiful like sheep in the Karoo (seeing that every fridge, freezer and aircon is a heat pump), I think you might just want to shop around for repairers with good price/service when you do need them.

My heatpump use 900W to generate 3.5kW of heat. To heat the 150L watertank it takes about 55min in winter and 45min in summer. That means I can heat my watertank for less than 900Ah or 1/10th fo a 10kWh battery if you need to (although it almost always runs from the sun)

If you have a high risk profile, like our resident smoke master, then perhaps stick to more basic technology like old school geyser elements that don’t have any moving parts or electronic circuits.
(But in that case you might also want to reconsidder if you should own a fridge or an aircon. :stuck_out_tongue: )

Emergencies here usually being a low battery SOC or a very large load.

actually… Heater water = nobody notices, Cold water = wife might stab me.

Right now this is looking like (and slap me if I’m being a DENSA member)…

use the grid feed option to supplement juice for the geyser? This should mean I don’t need to go crazy with the size of the inverter as I’d only be using excess juice from solar for the job?

As for heat pumps… I like the idea, I understand the maths (for those wondering… the primary bit that fails with load shedding providing that it’s not a random brown-out is the capacitor on the motor… have had that on both my pool pump and my aircon… they are relatively cheap to replace… not recommended for DIY if you tend to do “silly” things). The numbers I’m getting (what “people” tell me), are a little bit all over the place. cutting it to 1/3rd of the bill would be awesome though as I do know those tubes have a way of ruining your holiday.

I guess it adds option number 6 on the list… the dual element flange…