EdDee

Speak to Murray of "Industrial Thermal" in East London.... Regular Thermostat is still in place, so no worries... I Discounted that Idea.... I wasn't happy about the possible choppiness of the signal influencing the Inverter output... Read This: https://powerforum.co.za/topic/8728-how-much-surplus-solar-power-do-you-actually-have-and-how-to-find-out/ Cheerz E

With the average and reasonably well planned solar setup, there should be an excess of solar power on a reasonable to well lit day. This actual "excess" power is hard to determine and goes to waste, once batteries are full, the fridge is cold, etc etc etc, the system then starts drawing less from the panels via one means or another, waiting for load conditions to change... How do you know when, and how much, can be loaded onto your inverter at this point? Remember, this "point" that I refer to, is a dynamic point - This is what makes it tricky - Nasty things like clouds, mist, dust, sun angle, to name but a few, move our available solar target around quite a bit.... Now add to this, the deep freezer cutting in at seemingly random periods, the fridge playing games with the inverter whenever someone visits for a "cold one", and the problem actually starts to get quite "tricky".... But, it is actually quite simple to see what you have available at any given time - You have to throw a bit of hardware at it, unfortunately, but we are not talking about a big pile of lightning soluble silicon - It is, at best, 3 small components (or sets thereof) that you need in addition to each bank of oriented panels - ie, N panels all at same inclination, 1 set components, E panels at a particular inclination, another 1 set of components, and so on .... Disclaimer: Note the Forum Title - Home Automation - This post assumes you have some form of home automation in place and working, and you are monitoring and controlling your household in some way already.... The components needed per Bank of Panels: 1xSonoff Basic Flashed with Tasmota, 1xADS1115 Ad Converter hooked to it, 2x Resistors to act as a voltage divider, 1x Tiny little solar cell, match your Resistors to divide the voltage to slightly less than the maximum acceptable input on the ADS1115. Hook the above together, (There are plenty of internet tutorials to do it.) and get the numbers feeding back from the Sonoff/ADS onto your wifi network and into your logging system... Next, put the little "metering panel" in the least advantaged spot on your array of choice(Last lit, first shadowed), parallel with, and at the same inclination of the panels themselves - this is important! Now start watching the numbers, recording them if you can... There is just going to be too much data to do it properly on the fly, but it isnt that complex... As the sun strikes the metering panel, you will get digital values back from the metering sonoff corresponding to the solar intensity available - At any given time, these numbers indicate the actual solar available - Lets say the metering numbers max out to 28532 on a crystal clear day with no clouds(This is your max nominal value). Later in the day, you check it out and the metering number is now 12555... That means that at that point in time, under those specific atmospheric conditions, you are getting 12555/28532, ie around 50% of the maximum available power for that particular meter, and as such, for that particular bank of panels that it is associated with... Does it work? Definitely yes... Is it accurate? Reasonably so, I have been running my system with one of these on the main bank for around a year and it has allowed me to "forecast" what I can load onto the inverter very nicely. Calibration: This can be tricky and requires patience - Well worth doing to get the best out of your system that you can. To do the calibration, you need to bear in mind that it is best done when the batteries are fairly low in SOC and not being charged at maximum allowable current as set by your inverter parameters - This means that all available power from the panels is being used at that particular moment in time. Look at the power being delivered by your panels - Lets say its 3450W - Look at the numbers from the solar meter - Lets say it is, for example, 18505 - Now, open your calculator and do some maths - 18505/28532 = 0.65 ie 65% of total max solar availability - We also know now that 65% of total availability is 3450W... therefore the max we would nominally get from the bank is around 100/65 *3450 ie 5307W .... Now look at the spec of your mppt/inverter .... Although the panels can supply the power, will the inverter or charger limit what is available - If so, use the lowest limit under these circumstances... Real World Application: The sun's shining, the batteries are full, the beer is cold.... The panels are putting out 800W,.... It's midday... There are no clouds... The metering system says 26222... This means that at that particular moment in time, the solar power availability is: 26222/28532 ie 0.92 or 92%... The power that is available from the panel bank is .92 x 5307, ie 4877W .... But hey, our inverter is only capable of 4500W, so in total, we have 4500 less the 800 we are already using.... So we have an additional 3.7Kw we can draw for something useful.... Time to automate your geyser, aircon, fish pond, pool pump, irrigation system, grey water recycling.... And let it use the power that would otherwise just be ignored..... This is NOT a theoretical scenario, I am running my system in this manner and I have found that my solar harvest has dramatically improved by doing so... To do the switching manually, however, is not practical, it does need a home auto system to get the best out of it.... Especially with those pesky clouds...... Cheerz Ed Here is a section of graph as pulled 5 mins ago... Legend: Orange: Unused Solar/Blue: Used Solar/Red: Inverter Output/Purple: Inverter ACVA In/Light Blue line-Metering Estimate

Faced with the costs of "Wonder Gadgets" to heat water from excess solar availability, I have come up with a different way of doing it.... I have already had, for some time now, a raspberry pi hooked to my inverter monitoring and controlling various bits and bobs around the place... One of my greatest frustrations is the "lost solar" power that is often available during the average day.... This hot water system but one small addition I have made to try and utilize this unused power. I put in an order to a local (EL) company for a triple 220V geyser element. It wasn't as pricey as I expected. The 3 elements are 500W/750W/1000W respectively, all on a single screw in, standard fitting (with an extra long thermostat pocket as well, which reaches well beyond the ends of the elements.). The long and the short of it is, using my pi/mqtt/fabricobbled system, I can get a pretty close estimate of what inverter/solar power is available beyond the immediate consumption at any given point in time... Using a small "Sonoff" wifi switch, hot wired to a quad 10A relay board, a bit of Node-Red and some head scratching, the net result is, well fantastic! If there's 500W excess available, turn on the 500W element... Same for 750/1kw.... Need more? Turn them on in combination, to step in 8 steps, 0W to 2.25Kw as needed... The extra deep pocket for the thermostat got a Sonoff with a DS18B20 temp sensor to feed info back into the mqtt as well.... (Yep, you can series the elements as well with a bit more head scratching to lower the wattages still further, but lower than 500W is a waste of time as I have found out...) Safety? Sure... Using the existing Thermostat pocket in the geyser, there's a good old fashioned clicky-clicky rod slotted in... Hooked up to the common neutral of the 3 elements... If he's unhappily hot, everybody shuts down... And... It works... Well! Total cost of the additional bits was less than ZAR1K, its been running for about 6 months now and barring some really crappy weather, the household of 4 has used very little gas in the geyser system over the period... Cheerz... E

Nothing is ever finished... Lol.... Plenty more been added, switched loads on solar availability, solar availability tracking, 433mhz rf remote fob support, more household integration.... E

The little project is coming along quite well now... Giving me all the info I have needed.....Anybody interested can take a peek at: http://www.digipoint.co.za:85/emoncms/dashboard/view/&id=6 Cheerz E

If anybody is interested, I have modded a few of the gauge widgets in both looks and function, along with some customized backgrounds for them...Small stuff, I know, but they seem to work quite well... If anybody wants a copy, shout and I will post them here.... The gauges are semi transparent, allowing for easily changing the backgrounds.... On the dual-needle gauges, I have made provision for dual units to be defined as well... Now you can have Volts/Hz for instance on the same gauge with the correct units displayed for each...

Another couple of screen shots, there are more dashboards, but these are the lekker ones I have almost finished with...

If interested, take a look here: http://www.digipoint.co.za:85 ...this is a gateway into the little system I am playing with and putting together...

Hmm...interesting....looks like people are lurking in the background and watching this post as we speak....

Giving it a good workout.... House, office, dishwasher, bit of cloud....

You can get all the software stuff to do the install from here: http://www.solpiplog.tk/ You can get the Pi from here: https://www.pishop.co.za/store/ Then have fun setting it up and making up your dashboards...

Solpiplog for the data collector, Emoncms for the logging, A few hours spent setting it up from scratch... Runs on RaspberryPi.....Download from ..... Uhhhh.... Cant remember, Goegel it! .... All free/open source...have fun!

Been playing with some "Other" software.... Here are some temp links into the dashboards... Take a look if you are interested.... http://www.digipoint.co.za:85/emoncms/dashboard/view?id=12 http://www.digipoint.co.za:85/emoncms/dashboard/view?id=13 http://www.digipoint.co.za:85/emoncms/dashboard/view?id=14 http://www.digipoint.co.za:85/emoncms/dashboard/view?id=15 http://www.digipoint.co.za:85/emoncms/dashboard/view?id=16

Thanks for the contact details Jaco... Dropped him a line and left a message.... Cheers E

Hi Jaco, I am new here.... The only postings I have made are on this thread so far....Unless, of course, you owed the "other Ed" some money...then I am glad to collect it for him! Cheers Ed

Hey Guys, I am wanting to get hold of Manie, of ICC fame... Any contact details you can throw my way? Regds Ed....(Of above E&G Fame, now you can moan at me directly!!)