Hi All,

I have a geyserwise delta-T system that circulates water from a roof mounted collector plate back to my geysers (2 x 150L in series) via a pump. 2 years ago I got a 5kVA hybrid inverter system installed and asked the installer if it was possible to keep the geyserwise system on the inverter so that when there is load shedding, the circulating pump on the geyserwise keeps running to (a) ensure that the plate doesn't overheat and (b) we keep getting cheap/free hot water when the sun is out. The geyserwise system obviously also needs to turn on the geyser element on overcast days when the collector plate would be ineffective. However the geyserwise system is supplied by the inverter (essential network) and the power to the element is on the eskom mains. So the solar installer used some sort of solenoid actuator (not sure) so that the geyserwise unit can control mains power to the geyser element even though they are on different networks. Well done if you've read this far.

However I find the whole system to be a bit complex and not exactly robust or user friendly. For example, occasionally, the geyserwise will "try" to switch on the geyser element when there is load shedding. But the geyser never heats up and the geyserwise unit reports an element fault because the temp sensor notices no increase in geyser temp despite it sending power to the element. Trying to explain any of this to a potential tenant is a mission. I'd like to try and simplify everything and have a few questions:

1. Having the geyserwise on the inverter and the geyser element on mains has resulted in some untidy eletronics, as explained above. It might be better to just put everything geyser related back onto mains and live with the fact that occasional load shedding will prevent me from maximizing my collector plate's potential. However I'm still left with the issue that temps in the plate get incredibly high if the circulating pump doesn't work. Does anyone know how likely I am to damage this plate it its just sitting in direct sun for 4 hour load shedding stretches? I've battled to find any literature.
2. If anyone knows of any other smart ways for a geyserwise system (on an inverter) and a geyser element (on eskom mains and therefore subject to load shedding) to work in tandem, I'd appreciate suggestions. Maybe my current setup is the only option.

Thanks in advance...

Hi Nick,

 

I have a similar setup although I decided on evacuated tube collector and just had my electrician connect the geyser to a change over switch with which I can manually (does not happen often) switch between Eskom and my inverter. Sometimes I just switch on the element for a while to boost the water temperature like I did today. I still want to try and automate that, but I would typically only do it when the battery has reasonable charge and there is some sun. When it is really overcast, I switch the geyser to Eskom, switch the element on an just let it heat up without drawing from the inverter.

 

Regards,

Heine

I use the Thingwala upgrade - took me like 5 minutes to install. Using it I can disable the element based on an automation in Home Assistant. And my wife loves the app because she can boost the hot water when she is on her way home.

@heine I'm interested in your setup please. I also have the tubes and a 5KVa Sunsynk. Currently my geyser is not wired through my inverter from my main board and 99% of the time the tubes give me enough hot water. Occasionally, when we have a few bad days, I simply switch on the geyser via Geyserwize, pulling from Escom, for an hour or 2. I don't want to pull from my inverter as I may exceed my load.

Ultimately I want to turn off my mains - and disconnect from Escom. I have a gensec wired into my inverter should Inreally need it (lots of rainy days, etc). The problem is if I turn off my mains now, after a few days my geyser solar battery dies and I lose the geyserwize panel. From what I can see the Geyserwize only takes a single mains input and then outfits AC to the geyser and DC to the panel. Is there a way to have the Geyserwize pull it's power from the inverter but the geyser power only gets powered from Esckom (or in future a direct line to my gensec via a cutover switch that decides whether to feed the inverter or the geyser?

Hope this makes sense...

4 minutes ago, Neil.inSA said:

@heine I'm interested in your setup please. I also have the tubes and a 5KVa Sunsynk. Currently my geyser is not wired through my inverter from my main board and 99% of the time the tubes give me enough hot water. Occasionally, when we have a few bad days, I simply switch on the geyser via Geyserwize, pulling from Escom, for an hour or 2. I don't want to pull from my inverter as I may exceed my load.

Ultimately I want to turn off my mains - and disconnect from Escom. I have a gensec wired into my inverter should Inreally need it (lots of rainy days, etc). The problem is if I turn off my mains now, after a few days my geyser solar battery dies and I lose the geyserwize panel. From what I can see the Geyserwize only takes a single mains input and then outfits AC to the geyser and DC to the panel. Is there a way to have the Geyserwize pull it's power from the inverter but the geyser power only gets powered from Esckom (or in future a direct line to my gensec via a cutover switch that decides whether to feed the inverter or the geyser?

Hope this makes sense...

Hi Neil,

I think it makes perfect sense. Irun solar-assistant (https://solar-assistant.io/help/getting-started/prepare-device) which I see appears to support Sunsynk inverters too. Solar-assistant makes it very easy to configure rules such as, switch to Eskom when battery power drops below X. I ran my Geyserwise PTC element (https://livestainable.co.za/products/geyserwise-2kw-230v-stainless-steel-ptc-geyser-element-2000w-ac-only?variant=43669700608180&country=ZA&currency=ZAR&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=Cj0KCQjwna6_BhCbARIsALId2Z0gT62T5gpLeDw2t85-oQNwNH8OdKndp23Q4OnxU5nqsG88UlFSr4caAm-iEALw_wcB) from a single 5kw Kodak when the tubes did not generate enough power until not too ago using Solar-assistant and also some additional home automation (Homeassistant) to manage total load. I now have 2 x Kodak 5kw and more panels so life is less complicated as far as managing the load. I was actually able to pay for much of the expansion using my calculated saving from my initial system over a couple of years.

I also decided to go with a AC powered pump for the tubes and that is connected to my inverter too. Why another battery and tiny solar panel I reasoned.

You don't mention which area you reside in. Here in Cape Town and surrounds we really struggle a bit with solar generation during winter. You might not have those issues to also consider.

In all honesty, if I had the opportunity to do it all other gain, the one thing I would change would be rather go for a heat pump instead of the tubes. In summer, I often have to cool down the water overnight using the Geyserwise "away mode", but in winter it is a challenge and often have to boost the temperature using the element, Having said that, if you have a regular 3kw or high element for your geyser, I would suggest be very careful with your current 5kw setup. Downgrading the wattage and/or going for a Geyserwise PTC element might be something to consider.

What I also did when I only had a single 5kw inverter was install a change over switch for the geyser which allowed me to switch to Eskom directly in winter and via the inverter in summer and then still had Solar-assistant to manage the actual source of power during summer.

Hope it helped and I didn't confuse the heck out of you. If there is anything unclear or you more question please reach out.

Kind regards,

Heine

Thanks for the very useful info @Hein! I’m actually JHB based and I find with the good winters we have here I get pretty decent hot water all year round. Only a few occasions when we have a few dull days do I need to top it up via the element and in that case the plan is to just top up via the gensec directly (I have a 3 way cutover for that in place (gensec / off / direct grid not via inverter).

I’ll definitely look at changing the geyser pump to an AC version on the inverter. They say adding a second small panel to the existing tube installation will improve battery charging and sort the issue I have currently where the battery dies after a few days of poor sun. But AC would be better.

Thanks again!

Just now, Neil.inSA said:

Thanks for the very useful info @Hein! I’m actually JHB based and I find with the good winters we have here I get pretty decent hot water all year round. Only a few occasions when we have a few dull days do I need to top it up via the element and in that case the plan is to just top up via the gensec directly (I have a 3 way cutover for that in place (gensec / off / direct grid not via inverter).

I’ll definitely look at changing the geyser pump to an AC version on the inverter. They say adding a second small panel to the existing tube installation will improve battery charging and sort the issue I have currently where the battery dies after a few days of poor sun. But AC would be better.

Thanks again!

You're welcome