Hi Guys

I have got a good setup running for my home 12 x JA Panels, 4kw Inverter, and Supercap. Works like a charm. Except I don't run my geysers on it as it will overload the system and drain the cap in no time.

I was wondering if any of you guys use an inverter on the geyser only ? And if so what inverter is it ? I want to get my geyser on an inverter with solar only (no battery) so the inverter would need to be capable of running without a battery. Should solar not be available it should fail back to grid.

 

My problem is I have 2 x Geysers so if I can get an inverter setup with solar then I will  alternate the times they heat up.

 

I have looked at geyser wise etc they all come in around 20k for 150l geysers (problem is my 250l geyser uses up to 4kw to heat) so geyserwise etc won't work

Get a solar geyser, much cheaper and more effective.

8 hours ago, Treschen said:

Hi Guys

I have got a good setup running for my home 12 x JA Panels, 4kw Inverter, and Supercap. Works like a charm. Except I don't run my geysers on it as it will overload the system and drain the cap in no time.

I was wondering if any of you guys use an inverter on the geyser only ? And if so what inverter is it ? I want to get my geyser on an inverter with solar only (no battery) so the inverter would need to be capable of running without a battery. Should solar not be available it should fail back to grid.

 

My problem is I have 2 x Geysers so if I can get an inverter setup with solar then I will  alternate the times they heat up.

 

I have looked at geyser wise etc they all come in around 20k for 150l geysers (problem is my 250l geyser uses up to 4kw to heat) so geyserwise etc won't work

I have 2 150lt geysers and install a vacuum tube system from hudu (franchise is long closed.. story for another day) the 18 vacuum tube system with a 12v solar circulation pump heats up the water most days of the year just fine and my heating elements in the geysers only work when I have guests over or Someone takes a long shower off the agreed schedule!

the system paid itself off in less than six years. It cost me 18k back in 2009.

9 hours ago, Treschen said:

I want to get my geyser on an inverter with solar only (no battery) so the inverter would need to be capable of running without a battery. Should solar not be available it should fail back to grid.

I have 2 x 150l geysers and 2 x Geyserwise units.

Geysers heat up after batts are charged so no batts are used for any geyser as the system is set to "Keep Batteries Charged" when the 1st geysers starts heating as 12pm.

Grid tied helps a LOT to simplify the system.
 

9 hours ago, Treschen said:

I have looked at geyser wise etc they all come in around 20k for 150l geysers (

The actual Geyserwise unit, the thing that makes it all work i.e. timer etc, is like under R1k for the bottom of the range non-solar one.

Hi Treschen 

How did you solve your issue? I’ve got a5kW inverter grid tied with 15kW battery - runs my entire house and pool. Everything except geyser. Had a solar panel geyser. Not impressed with it (water just never got hot enough and therefore for a household of five we constantly struggled with consistent hot water - could be due to the fact that the geyser installed was a 300l?!) and seems like the solar is not working at the moment so at the moment we’re paying electricity for hot water. 
 

i was also thinking of getting a 3kW parallel inverter not touching the batteries specifically for the geyser. This should give us the benefit of less grid usage and consistency of hot water ?

Hi @Reena

There are different type of solar heaters e.g. flat plate, evacuated tubes, and pv. The solar unit you have may not be adequate for the larger geyser volume.

@Treschen

if you install a larger geyser or add another, you may run into less of a warm water issue. With a 300 liter geyser I would think that 4x PV panels and a 2000W AC/1100W DC element will do the job.

Heating my 150l geyser with 2x 330w pv panels and a Geyserwise 1500W AC/900W DC ptc element works well. In the summer I do not have to top-up with AC power.

However, you family's behavior will have an effect on the sizing of a solution. E.g. how much water are consumed and when in the day; this has a direct impact on power consumption.

Just to add a handy tool in sizing a system. One needs 175Wh to increase the temp by 1 degree for a 150L geyser. This is 7kWh from 20 to 60 degrees. Thus 2h20min with a 3kW element.

37 minutes ago, Scorp007 said:

Just to add a handy tool in sizing a system. One needs 175Wh to increase the temp by 1 degree for a 150L geyser. This is 7kWh from 20 to 60 degrees. Thus 2h20min with a 3kW element.

That helps. I guess a geyser is hardly ever 20 degrees, so one probably needs less. I had a quick look now and my home assistant energy dashboard tells me we averaged about 4.5kWh per day on our 150l geyser this last week (family of 5). 

12 hours ago, Speedster said:

That helps. I guess a geyser is hardly ever 20 degrees, so one probably needs less. I had a quick look now and my home assistant energy dashboard tells me we averaged about 4.5kWh per day on our 150l geyser this last week (family of 5). 

In winter time incoming water can be very cold. Early this evening my wife took a bath and my 150L geyser was at 22 degrees. It might have included some hot water for washing up in the sink before running a bath. 4.5kWh per day is surely low. Heat loss alone could be close to 2kWh per 24 hrs on an older geyser. I saw the latest Kwikot has better insulation.

On 2022/07/09 at 7:27 AM, Reena said:

Hi Treschen 

How did you solve your issue? I’ve got a5kW inverter grid tied with 15kW battery - runs my entire house and pool. Everything except geyser. Had a solar panel geyser. Not impressed with it (water just never got hot enough and therefore for a household of five we constantly struggled with consistent hot water - could be due to the fact that the geyser installed was a 300l?!) and seems like the solar is not working at the moment so at the moment we’re paying electricity for hot water. 
 

i was also thinking of getting a 3kW parallel inverter not touching the batteries specifically for the geyser. This should give us the benefit of less grid usage and consistency of hot water ?

@Reena

Just recently installed a 8kw sunsynk with 16 x 545watt JA panels, I have a 4kw chugger of a geyser and 2.4kw smaller geyser they both on timers I will cycle them at different times during the day... They both on non essential side of the sunsynk tomorrow will be day two with the new system so need to see how much of PV can feed back to the geysers. But by 9am today I saw around 3000 watts coming from PV charging the battery.

 

I looked at solar conversations but kept had guys telling my 250l geyser is too big for that and I should change the element to a 3kw element, now that is all good for me but my family is used to the geyser heating up in an hour... I can imagine my wife coming at me because it takes 2 hours 😂

 

Ultimately maybe get a heat pump ? With timers big geyser runs daily 4am to 7am. 4pm to 8pm of course this will change with the new system 

Edited July 26, 20224 yr by Treschen

**Edit** With the new setup I power the 4.4kw geyser from PV during the day takes about 1h15min then I turn on small geyser this is soon going to be fully automated with Node Red. Able to power geyser from batteries during the morning loads and that takes my batts down to 20%. So now based on this its a tough choice between getting a heat pump or adding a third battery. For cloudy/rainy nights its give and take and I will rather just run purely on ESKOM and leave batts fully charged, as there will be no point to power loads from battery on cloudy nights. 

Adding 2 more 545 watt panels tomorrow as well.

29 minutes ago, Treschen said:

So now based on this its a tough choice between getting a heat pump or adding a third battery

How about installing solar direct heating panels for the geyser? They are much more efficient than PVs. Yes, it may require a small water pump with a Geyserwise control system, assuming that you are in a region without seasonal freezing temperatures.

3 minutes ago, Beat said:

How about installing solar direct heating panels for the geyser? They are much more efficient than PVs. Yes, it may require a small water pump with a Geyserwise control system, assuming that you are in a region without seasonal freezing temperatures.

Open to options will look into this and associated costs 

1 hour ago, Treschen said:

Open to options will look into this and associated costs 

Luckily we all have different ideas. PV is fine as it can generate power for any need. I would never go the solar panel route to only heat the geyser and then do nothing if one can generate power for own use from PV. PV is like a tractor, lorry and plaas bakkie all in one. 🤔🤔🤔

29 minutes ago, Scorp007 said:

Luckily we all have different ideas. PV is fine as it can generate power for any need. I would never go the solar panel route to only heat the geyser and then do nothing if one can generate power for own use from PV. PV is like a tractor, lorry and plaas bakkie all in one. 🤔🤔🤔

Yeah at the moment with the 2 additional panels I will have more than enough on tap for those sunny days. My main aim now is to get temp reading from the geyser just so that I have an extra value to determine the geyser final state allowing me to switch it off based on that, but its 2022 and we don't have an off the shelf solution for this...... sigh 

3 hours ago, Treschen said:

Yeah at the moment with the 2 additional panels I will have more than enough on tap for those sunny days. My main aim now is to get temp reading from the geyser just so that I have an extra value to determine the geyser final state allowing me to switch it off based on that, but its 2022 and we don't have an off the shelf solution for this...... sigh 

Easy to have remote temp info via APP on your phone. Have 8 switch on and off settings. Geyser wise I think has only a few on/off settings. Users can expand on it.

Just not sure of a easy way to switch that 4kw load of the element.

1 hour ago, Scorp007 said:

Easy to have remote temp info via APP on your phone. Have 8 switch on and off settings. Geyser wise I think has only a few on/off settings. Users can expand on it.

Just not sure of a easy way to switch that 4kw load of the element.

Not sure about easy but need to read the geyser temps without compromising the safety that a thermostat provides

15 minutes ago, Treschen said:

Not sure about easy but need to read the geyser temps without compromising the safety that a thermostat provides

I am sure other guys have Sonoff TH16 as a remote temp control coupled to Sonoff basic driving a relay that powers equipment.

Some time ago I used a Sonoff via relay to drive a heat pump and geyser. Both came on at the same time but each still had their own thermostat. No sure how to use the single pocket on geyser with the element as well as the TH16. Have never had a need for working out how in detail. Sonoff do indicate the TH16 can interface with other Sonoff units.

I installed a thermostat pocket on the one side of the geyser. It is in the port that is usually used when the geyser is installed vertically. For horizontal installations that port is plugged. Similar to the image below. 

Then used a Wemos d1 mini and three DS18B20's to read the temps, all managed with Home assistant.

The DS18B20 slides into the pocket.

 

I see the Sonoff TH16 has been continued locally and I think it has been replaced by this unit - SONOFF TH Origin Smart Temperature Humidity Monitoring Switch (TH10/16 Upgrade Version) (itead.cc)

23 hours ago, Scorp007 said:

Luckily we all have different ideas. PV is fine as it can generate power for any need. I would never go the solar panel route to only heat the geyser and then do nothing if one can generate power for own use from PV. PV is like a tractor, lorry and plaas bakkie all in one.

Good for you. But I never meant to use solar heating panels only. I started my ecologic path many years ago with such an installation. It works fairly well. My experience shows that one needs approx 1m² of panels per person living in the house. The Geyserwise control shows the water temperature on its remote display. Its feeler fits with the thermostat into the same pocket. The control allows to heat electrically as a supplement as well scheduled as manually and programmable temperature controlled.

I then started to add the PV system with off grid inverter 2½ years ago. Both systems can live together and complement each other. Nevertheless the direct heating panels have much higher efficiency for heating than PVs. Also is hot water in the geyser a less expensive energy storage than batteries.

Edited August 12, 20224 yr by Beat

8 minutes ago, Beat said:

Good for you. But I never meant to use solar heating panels only. I started my ecologic path many years ago with such an installation. It works fairly well. My experience shows that one needs approx 1m² of panels per person living in the house. The Geyserwise control shows the water temperature on its remote display. Its feeler fits with the thermostat in the same tube. The control allows to heat electrically as a supplement as well scheduled as manually and programmable temperature controlled.

I then started to add the PV system with off grid inverter 2½ years ago. Both systems can live together and complement each other. Nevertheless the direct heating panels have much higher efficiency for heating than PVs. Also is hot water in the geyser a less expensive energy storage than batteries.

We don't always have to think about batteries when wanting to heat a geyser. A low cost grid tied only or string inverters can also be used to provide the 220V power to element from the sun. Then it works at the same times that solar plate or tubes would work. 

No fancy controllers. Just the normal thermostat.

@Treschen

The Astute smart controller is now priced at R499 at Chamberlain's. 30A resistive load. 10A inductive. Then you just need to sort out the remote temperature.

KISS does apply sometimes. 

Edited August 12, 20224 yr by Scorp007

22 minutes ago, Scorp007 said:

Then it works at the same times that solar plate or tubes would work. 

Sure! But you would need about 4 to 6 times more PV panel surface compared to heating collectors to get the same heating power.

Edited August 12, 20224 yr by Beat

5 minutes ago, Beat said:

Sure! But you would need about 4 to 6 times more PV panel surface compared to heating collectors to get the same heating power.

I have no figures so will accept it. PV does open up use for other power use at the expense of space.

That why I mentioned earlier there are so many options available.

One guy would insist on having WiFi for a geyser wise @ R2800 the next guy would go for 2 x PV panels instead.

Perhaps an EV solar geyser conversion is a better option but my experience with the flat panel geyser conversion has been a mixed bag. OK to good in Summer and mediocre in Winter. I got mine about 5 years ago at a fairly reasonable price.
Then I had my PV system installed a year ago and I use that to power the geyser element to the max the Geyserwise allows (65C). Even when the water temp is at 30C in the morning, it takes about 1:30 max to heat the water to the max. The flat panel then heats it further during the day.
Considering the costs of the Geyser conversion at the time  I could have had 4 to 5 more of my PV panels.
Now that I have PV, I would never reconsider a solar geyser as the efficiency of the 3 kW element cannot be beaten (that is to say if you have enough spare solar capacity and don't use grid power).
My Flat Panel on it's own before PV used to get to around 55C after a full day in summer also starting typically at 30-35C with no usage of the element.