PaulF007

I would suggest you first go to an Auto electrician with a multi meter and ask him to show to you the difference between parallel and series connections else you almost certainly are going to create some magic smoke... Dc is not something you should bugger around with if you don't know the basics. 12v is fairly low but the Amps could burn you badly....

As far as I know yes , but they also have an extensive Wiki page so if you are not sure of the device have a look to confirm. The basic is very well supported but you could also have a look at the Wemos d1 mini. You can have up to 8 io ports in one device.

Have a look at Jonathan Oxer's website , he has been involved with house automation for many years. Interestingly he moved away from all interfaces and is now using Node Red UI for his system.

Been using Openhab now for almost four years . Here is a LINK of the setup I posted on another page. Personally I tested both and the reason why I went OH is that they have a Proxy server that works out of the box. You install the plugin register the on the site and add your UUI and Secured code. No need to port forward and it is for free. But apart from that I could not see much difference for what I an using. Also after three years you tend to know the interface so it is "easier" to setup

@Stef that is a cheap android tablet that I used.

It is looking good well done! Here is some additional points to consider. Ensure that the geyser will not switch on while you are on battery power unless it is not a problem and you battery bank can handle it. One way of handling it is to ensure that the contact is powered from the grid feed. Should the grid fail the contact can not close. Have some way of monitoring your battery watts should the draw be lower than ,for example , -2000 w let it switch of the geyser. Have a hard timer in the loop so that the geyser can only be switch automatically during day time unless you do it manually. The assumption is made that you have a non grid tie inverter and that you need to switch between grid and solar if you have grid tie then 2 and 3 is not that important but I will look at 1 for protection of the batteries.

Getting back to the Original question If I do the same "Straight-line" comparison I use about 12 kwh of alternative energy (Solar + Batts) so this will give me R 63 saving per day. Keep in mind I live on a farm with prepaid but no line rental so the price per unit is very high but I only pay for what I use from the grid.

Ok , so this project has been ongoing for the last three of four years and in fact is still going on we have learned a lot on hydro power and possible pitfalls. but I wont bore you all with the details. Here is what the "final" product looks like. Ps. Not my system , hope to have one going in a year or so - (Need to raise the capital )

Still a work in progress. But I have build a dash to display all the different alternative energies on one page.

One more idea , should any one look at this. Most alarms have an audio output , 12v , to drive siren. So 1) Dead simple method - 12v - 220v contact to the lights. They will then come one if the siren is activated and switch off if the siren is off. 2) 12v interval timer. - If triggered run for 10,20, 30 min and then reset. Wire the light in parallel with the relay so that you still have control to manually switch in the lights. There is a ton of other ways to do it but this is , in my mind , the dead simple method if you want to drive it from an existing alarm system.

Looking good. Well done. You should also notice that when you start to run hot water the temp will spike as the hottest water will be on top. As the old saying goes " he who measures will know" ...

@JJS - What is the full speck of your system and how do you monitor your data the values does not seem correct on average you should see conversion losses of about 15% - 20% .

Here is a thought , span the begees out of those contact numbers. Keep the crook busy so he does not have time to scam ignorant/desperate people.

Sure it is quite simple. So i have a SonOff running Tasmota on it . You will need to flash the sonoff with the new firmware. This will add the benefit that you can add atleast 3 sensors to the SonOff , (TX , RX and GPOI14 , I think thats the last pin). In tasmota to you just select the correct sensor for the pin that you connected that DS18B20 sensor. Here is a tutorial as to how to wireup the sensor. The nice part of tasmota is that every thing is already done and you only need to add the broker details and it will publish to sensor data to the "tele/#/SENSOR" topic. Here is some pictures of the Tasmota setup. There a lot of info as to how to flash the sonoff switch with tasmota , alternatively you could also use a Wemos D1 with Tasmota loaded to do the same. Last thing is that I placed the sensor where the normal thermostat of the geyser would go. So that was quite easy

A buddy of mine used a old Android connected to the mains. There is an app that will send you a SMS , guess maybe another trigger if the phone stops charging / grid fail. Simple but very effective. If you want to go one step further you could use something like Tasker (Android) - then you can have all sorts of stuff setup when the grid fails.