LiveBootleg

Howzit guys. Its been a while since I've been on this forum but thought I would share what I've implemented at the end and answering some of the questions that has been asked throughout this thread. Firstly, a note on the solar system I installed. I installed 2 Growatt inverters (2 x 5kw), 9.24kw solar panels (28 x 330w) and 14kw batteries (4 x 3.5kw Pylontech). I'm usually running out of battery between 4am and 6am every day so I will be adding another 4.8kw battery soon. I installed this in November 2020 so its been running smoothly for over 2 years now, effectively cutting down on 80% of my Eskom bill. I've got a garden flat and an office over and above the household that it needs to power. When I installed the system, Growatt was the only inverter that was supported natively by Home Assistant as an existing integration already existed (https://www.home-assistant.io/integrations/growatt_server/). Now if I had to do this again I would probably go for a SunSynk 8Kw and use something like Solar Assistant (https://solar-assistant.io/) to plug it into my Home Assistant. I also considered Geyserwise - they have dual elements with 2 power sources (Grid & PV). Firstly at the time I installed this - there was no integration available into Home Assistant. There has since been some Geyserwise API's released but no formal integration, some people built their own solutions by scraping from the website and others plugged in ESP8266 modules to replace the Geyserwise Wifi module but I did not choose to go down that route. So my main requirements are: 1. Ensure we have hot water in the mornings 5am when my wife and I shower and in the evenings when the kids bath 2. Use as little of Eskom as possible (preferably nothing) and effectively maximise the use of PV power 3. Do not use any battery capacity to heat the geyser 4. Do this in an automated way where I don't need to look at different apps every other hour to switch things on and off Also worth noting, I had an additional spare 150l geyser (replaced the kitchen geyser with a gas geyser) and I connected it in series with the existing one. The logic behind this was that you heat both during the day with PV and when the kids bath in the evenings the hot water is displaced from the secondary geyser to the primary one and in the bathroom the water should still be warm enough the next morning when we shower. Works like charm (only in summer though) ... Back to the question I originally posted - I went the route of installing a Hager 25A contactor (https://hager.com/intl-en/products/information/esc427-contactor-25a-2no2nc-230v); installed by an electrician of course and bought it ElectroMechanica (https://www.em.co.za/ESC427) - one for each Geyser. The diagram basically depicts what I've got but in principle there are 4 lines: 1. Geyser 1 Grid 2. Geyser 1 PV 3. Geyser 2 Grid 4. Geyser 2 PV The two contactors then narrow this down to the power supply to each of the two geysers. The electrician was concerned about the contactors getting warm so we installed another wifi switch to only switch the contactors on when I need to heat them up with PV. When the contactors are switched off - the supply from Eskom still works. I also still have normal 20A circuit breakers for every line - this was also just a precaution and for CoC purposes. So this is how my setup runs today: I have an automation on Home assistant that runs in the afternoon between 12pm and 4pm. It switches on the PV supply for both geysers, however it checks every 5mins if its still using power from the PV and in case it starts drawing from the battery (probably because its overcast outside), then switch off the PV supply and switch on the Grid supply. This ensures we've got enough hot water when the kids take a bath at night and the battery does not run out. In the morning - I run another automation at 3am which firstly checks the geyser temperature (Sonoff TH16 which is not installed inline with the geysers at all) and if the temperature is below 40 degrees - it will switch on the Grid supply to heat it up. Best case scenario is in summer when the sun is shining in the afternoon and its not too cold outside - I use no Eskom power to heat up my geysers and we've got more than enough hot water. Todo: The only challenge I have currently is if we have loadshedding during 3am and 5am and the water is not warm enough. I still look at the loadshedding schedule for the next day every evening and amend the morning geyser schedule to run outside of the loadshedding window. The same would apply for an overcast day and when there is loadshedding between 12 and 4 - still need to figure this out.

Thanks for the replies - I will have a look into both and see what will work best.

I had a decent solar system installed at the end of last year and its been working really well. Only two lines in the original db was configured to stay solely on Eskom power, that being my stove and the other my geyser. The rest of house runs through the inverters and if the batteries are depleted it automatically switches over to Eskom. I am looking to refine the system a bit as I'd obviously like to have my Eskom usage as low as possible. One improvement opportunity I have is to heat my geyser in the day with PV power as I have a lot of spare capacity there. Currently my geyser (running only on Eskom) has a afternoon cycle to heat the water for the kids to take a bath at night, and another morning cycle before wifey and I take a shower in the morning. Now, I had a discussion with the solar installer (he is a qualified electrician) and he recommended installing a changeover switch - this will allow me to supply the geyser with PV power during the day and then with Eskom power at night. Having also jumped on the Home automation bandwagon using Home Assistant with great success across other areas around the house (alarm, lights, pool pump, irrigation etc) I would not want to go back in time and have a manual switch sitting in my db which I need to remember to switch over twice a day. I currently have a Smart circuit breaker in my db for the geyser (https://www.robofactory.co.za/home-automation/167-63a-1p-smart-circuit-breaker-with-monitoring-ewelink.html) which allows me to activate the timer in the afternoon and the morning using Home Assistant automations. I also get to switch it on or off using my mobile if there is a need and I also get the benefit of monitoring the power - either in real time or looking at the monthly stats. This works like a charm. My idea is to add a 2nd smart circuit breaker (same one), which feeds power from the inverter to the geyser and I can configure the afternoon cycle to simply draw power from the 2nd circuit breaker instead of the 1st one. That would swing roughly 50% of power usage on my geyser from Eskom to solar which will save me a bit more which is great. My challenge though is this: In the rare event where the software lets me down and for some bizarre reason both circuit breakers are turned on at the same time (should not happen, but what if it does?). Logic tells me that this will cause problems - I have very limited understanding of electricity and the implications of this; effectively powering a geyser from both sources at the same time is surely not ideal. So, how would I prevent this from happening by implementing a failover not using software? A manual failover switch will never allow the power supply from both sources, but how do I add a mechanism to the circuit breaker I have and the one I intend to install to prevent this from happening. This may not be in the correct thread, but please do advise - would love to hear your thoughts on this.

Hi, last week I had 2 x Growatt SPF 5000 ES inverters installed. The both came with a WiFi datalogger and my installer configured both of them on my ShinePhone app and they work as expected. Material was also supplied by GC Solar. Whereabouts are you located, perhaps my installer would be able to assist?