Vince, from Alberton (South East of Jhb),
Using a Microcare 15kw inverter and LA Gel batteries as a UPS for the unforeseen outages and loadshedding.
For now, planning to learn more before I move over to a PV / Solar system.
First step I want to do is make my home efficient. Have led lights in the entire house, I moved over to Gas stove, need to sort out the two geysers with a timer and blanket, etc etc etc.
In future would also like to upgrade the software of the Microcare inverter so I can move across to Lithium batteries, hopefully the Gel batteries last me for 5 years….by then the Lithium batteries should have come down even more
I can’t seem to find the answer to that question in any of the documentation, but I know from using them that reading data every second does result in different values every time, so the data must be updated at least that often.
That’s exactly how I tested the Carlo Gavazzis. I polled them as quickly as I could, recorded the values, and then I sat with a heat gun that I flicked on and off to make sure the power value ramps up and down all the time. Loaded the values into a spreadsheet and checked the most common delta between different values. So I determined:
The ones I mentioned are all excellent measurement devices. Do not get me wrong. My interest is on a much deeper technical level: Grid limiting.
When you use an energy meter to control the inverter power levels to ensure that you are not feeding energy into the grid, the ideal is to have a system that responds in under 2 seconds. Now as you can see, if the energy meter itself only updates about once a second, and you still have to allow room for the data communications and for the hardware to actually react to it, that’s a bit of a deal breaker.
But for just measuring household energy use, all the meters mentioned in the thread so far will be more than good enough.
Vince, if you don’t want to go super high tech and want something easy, you can check at the Shelly EM. There some local online shops that selling them but you can import direct from Shelly to. Will be cheaper then. We last did a bunch order between friends and split the shipping. I’m running one on my solar ac input on my db and one on the geyser.
So a quick test, just polling the grid voltage from a D111. It gets the grid voltage to 2 decimals, so it changes by small amounts all the time. At 700ms the value changes every time it is polled, at 600ms it changes most of the time, but is sometimes static for 2 consecutive readings and at 500ms it is mostly static for 2 readings. So I guess from that not very scientific test, I guess the values are updated every 600 to 700ms.