I had the opertunity to install this for a client today. He had 4x 460 watt panels that could not be used in his solar system.
I was so impressed with how quick you can install this. Use your old ac wiring as is and bring in one DC line with the correct protection. Phone app is exstreamly easy to use and with 4 basic settings you can set up everything. Install the app. Power up the unit, connect via WiFi, enter address and WiFi details, set PV only and required temp. App has a button to use grid should you require heating from AC and displays the Geyser temp. Complete instalation including the four panels we’re done in under 2 hours. Pv voltage rating is 60-230 volts
I think this is an awesome little device for someone with a few unused panels.
The client bought a complete kit. 20m 6mm solar cable, DC breaker and fuse and the thermostat for R6.9 k. Will look around and see if I can find only the thermostat somewhere without the rest. I am sure all the rest can be sourced at lower prices.
With a couple extra panels in the garage and R6k burning a hole in your pocket, I still think spending the money on a Solis PV inverter will be money better spent.
Depending on the rest of the setup of course.
I also like Solis inverters but I think the question to be asked is there a better way to heat water from PV panels.
I have argued this until I’m red in the face and I believe there are simpler ways than electronic voltage converters (be they AC or DC)
Thanks Plonk!
The problem I have with these plug and play PV geyser water heating kits is they aren’t transparent about how they convert the low voltage PV supply to the voltage required to power your 220V element…
Hi sir. To my knowledge they don’t convert, they send DC straight into the element. That works perfectly, converted a geyser to dc in2019 and still working until today. Took a little bit of modification. Had to use the contacts on the thermostat to switch a SSR. The solid state relay then switches the DC to the element.
That is true. There is much cheaper options for guys like us that wants to do it ourselves. Can’t offer that to a client that wants support at the end of the day. I will see if I still have the pictures of a mod I did in 2019. Used a normal thermostat to switch a SSR with 3 panels in series unto a normal element. Been working ever since with no ac connected to the geyser since then.
Agreed! DC is just as good as AC.
Yes there are challenges wrt switching DC but that’s about it.
As I have reiterated time and again is how do they convert the low voltage DC from a couple of PV panels and get 220V to drive the geyser element??
They don’t produce pure 220v. The element is resistive so will take 10v if it is available and start working. So 4x 40v panels = 160v @ 10a will heat the water.
The normal geyser thermostat could not handle switching the 120VDC and packed up in about two days. That is why I chose to switch 12VDC. The thermostat handled the 12V perfectly.
Too long ago, might be in one of my cloud storages, but have to look again later today. Its only pics of the final conversion. The client/friend did not want to use ac anymore, but if you integrate a normal changeover switch, you will be able to select between PV and AC.
Note: I would not change that over under full DC load. Or I will use two decent contactors as an Auto Changeover, but all of these components will add to the total project cost.
Price above is from an expensive distributor, shop around for petter pricing.
Man I am putting my head on a block here and might call @plonkster away from his breakfast table to correct me in making the following statement.
IMO a MPPT will be of little use in this specific application. This will be driving a constant resistive load and the current will be determined by the incoming voltage as the sun moves.
An MPPT is useful when you want to convert excess Voltage to current when charging a battery at a specific voltage.
@Jaco, note that the manuals you have attached are for the old Elon 100 and not the Elon Smart - the one in the blue box with wifi
I installed an Elon 100 system before the Elon Smart was available. This was to replace an evacuated tube pre-heater geyser (solar only/no grid connection). I am pretty happy with it and I was very reluctant to go the geyserwise DC element route.
The Elon Smart makes the installation much quicker and neater vs the Elon 100 and off course you have the internet connectivity with the Smart which I would have liked. One needs to remember that the efficiency of the Elons is not 100% as there is no MPPT controller. The solar DC is connected to the element directly as mentioned by fellow forum members. I installed 3x 475W and, so far, the peak power that I have gotten (V * A) is about 1050W. The daily power that I get is that is sufficient to heat the 150l geyser from 20 deg C to 64 deg C on a sunny day. In installed a simple temperature probe clamped to the flange in order to read the water temperature.
Finally, remember that the Elons only work on Kwikot geysers.
For the Elon Smart system manuals see Downloads - Elon Smart Water Solution