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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason

Elbow

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  1. Like
    Elbow got a reaction from Tamas in Pylontech vs Raspberry, Arduino, PLC   
    Hi,
    Here is a quick zip file of the program I use to poll the batteries over RS485 and push the read numbers out to OpenEnergyMonitor's MQTT server.
    Maybe it will be helpful.
    I'm not the original author - I just modified to publish over MQTT using a JSON structure, and to scan for batteries.
     
     
    pylon485-elbow.zip
  2. Like
    Elbow got a reaction from deapsquatter in Available solar power prediction   
    Hi,
    I made a NodeRed flow that attempts to predict available solar power.
    It does it using a node calls "Solar Power Forecast Plus" that takes your position, panel alignment etc and predicts the power that should be available.
    I then took a www-request node to request weather info from darksky.net, and attempted to factor in the cloud cover to try to come up with a prediction.
    The resulting info I send into MQTT to EmonCMS so I can chart it and so on.
    My flow looks like so:

    An export of the flow is also attached if anyone wants to play.
    The MQTT message generated looks like so - EmonCMS can import it nicely:

    You can see that right not the ideal available power is 3019W.  Darksky says there is 98% cloud cover, so my estimation gave 1243W achievable.  The formula is a guess, I used:
    actual = ideal * (1 - 0.6*cloudCover); I'm finding that Darksky overstates the amout of cloud - so my estimates are too pessimistic.
    Still - here's how it came out compared to actual yield this morning:

    You can see Darksky saying 98% cloud.  Nevertheless my actual yield was close to the "ideal" figure.
    The actual weather reported at Cape Town Airport is FACT 060900Z 16011KT 130V190 9999 FEW030 21/11 Q1015 NOSIG - ie few clouds at 3000ft.  Looking out the window there seems to be high clouds but its a bright day.
    Did anyone try to do something like this before?
     
     
     
     
     
     
    solar-prediction.flows.json
  3. Like
    Elbow got a reaction from Youda in Forecasting / estimating available solar power   
    Hi,
    I'm busy with a fun little project to make a little display of available solar power to put in the house to try to encourage running the high draw stuff when there is spare solar power.
    I used a little ESP8266 board and some led strips driven over i2c.
    For me the ESP8266 runs a program that listens to MQTT events from my monitoring and drives the display based on the worked out numbers.

    So on the right you see the current power usage in the house.  (Geyser was on so we are full scale)
    On the left the idea is to show the "available" solar power - at that time it was just a few watts.
    I might refine to use colours to show more info.
    But a challenge is that if there is no load there is no power from the panels.  So I want to show an estimate of the available power.
    The first part of making that estimate is the weather - yr.no has an API which should allow me to get an estimate of cloudiness.
    The second part would be the solar insolation at the address on the date.
    Those two with a fudge-factor should provide an estimate of what is available.
    Has anyone looked at this before - can anyone point me at a public API or dataset that can work our insolation for a lat/long and date?
    My idea was to mash together the insolation and the weather and come up with a "factor".  I can make this available on a public API.  User would query the API and multiply the factor by their system size and a fudge factor that gets the estimate to be approximately right for their results.
     
     
  4. Like
    Elbow got a reaction from Gabriël in I'm all official!   
    Yay.  All official!
    Thank you to @Rautenk, @Mike, @Carl, @Jaco de Jongh, and tons of advice from the ou manne of the forum and lots of others besides.
    What an interesting project - I learned a lot in the process and so far not a single shock!
    On a day when we face Stage 6 shedding I feel like very clever to have  this system in the house!
    Thanks,
    @Elbow / Steve
     
  5. Like
    Elbow got a reaction from Youda in Starting advice needed   
    Hi,
    I don’t have room for 16x3, which would have been great, but I did this, for my "essentials" only.
     

     
    You can see grid input with indicator, inverter output with indicator, changeover and red.
    Bottom left is the dedicated Cct and lights, right side is the plugs, all behind a 16a breaker to try to stop a plug overload from tripping the dedicated cct.
     
  6. Thanks
    Elbow got a reaction from Richard Mackay in Power outages   
    I've learned not to keep my hobby projects as hobby projects.  I remember my MythTV system 20 years ago.  Everyone would tell me I should make systems and sell them.  I was smart enough even then to know that what satisfied me would not satisfy a "it needs to just work" customer.  I hardly noticed the quirks.
    I've also done VOIP for nearly as long and in that space it took some time to get the wrinkles out and to be able to deliver service that just works.  We are there now, but its always harder than you think to get tech to the "just works" stage.
     
  7. Like
    Elbow got a reaction from Carl in Available solar power prediction   
    Hi,
    I made a NodeRed flow that attempts to predict available solar power.
    It does it using a node calls "Solar Power Forecast Plus" that takes your position, panel alignment etc and predicts the power that should be available.
    I then took a www-request node to request weather info from darksky.net, and attempted to factor in the cloud cover to try to come up with a prediction.
    The resulting info I send into MQTT to EmonCMS so I can chart it and so on.
    My flow looks like so:

    An export of the flow is also attached if anyone wants to play.
    The MQTT message generated looks like so - EmonCMS can import it nicely:

    You can see that right not the ideal available power is 3019W.  Darksky says there is 98% cloud cover, so my estimation gave 1243W achievable.  The formula is a guess, I used:
    actual = ideal * (1 - 0.6*cloudCover); I'm finding that Darksky overstates the amout of cloud - so my estimates are too pessimistic.
    Still - here's how it came out compared to actual yield this morning:

    You can see Darksky saying 98% cloud.  Nevertheless my actual yield was close to the "ideal" figure.
    The actual weather reported at Cape Town Airport is FACT 060900Z 16011KT 130V190 9999 FEW030 21/11 Q1015 NOSIG - ie few clouds at 3000ft.  Looking out the window there seems to be high clouds but its a bright day.
    Did anyone try to do something like this before?
     
     
     
     
     
     
    solar-prediction.flows.json
  8. Like
    Elbow got a reaction from Gerrie in Available solar power prediction   
    Hi,
    I made a NodeRed flow that attempts to predict available solar power.
    It does it using a node calls "Solar Power Forecast Plus" that takes your position, panel alignment etc and predicts the power that should be available.
    I then took a www-request node to request weather info from darksky.net, and attempted to factor in the cloud cover to try to come up with a prediction.
    The resulting info I send into MQTT to EmonCMS so I can chart it and so on.
    My flow looks like so:

    An export of the flow is also attached if anyone wants to play.
    The MQTT message generated looks like so - EmonCMS can import it nicely:

    You can see that right not the ideal available power is 3019W.  Darksky says there is 98% cloud cover, so my estimation gave 1243W achievable.  The formula is a guess, I used:
    actual = ideal * (1 - 0.6*cloudCover); I'm finding that Darksky overstates the amout of cloud - so my estimates are too pessimistic.
    Still - here's how it came out compared to actual yield this morning:

    You can see Darksky saying 98% cloud.  Nevertheless my actual yield was close to the "ideal" figure.
    The actual weather reported at Cape Town Airport is FACT 060900Z 16011KT 130V190 9999 FEW030 21/11 Q1015 NOSIG - ie few clouds at 3000ft.  Looking out the window there seems to be high clouds but its a bright day.
    Did anyone try to do something like this before?
     
     
     
     
     
     
    solar-prediction.flows.json
  9. Like
    Elbow reacted to plonkster in Inverter USB   
    Woooah! That is interesting! One thing I've been thinking of is making a Venus appliance for Hassio. Cause Hassio appliances are just docker images. The one thing I was unsure of is how to pass devices from the outside (host OS) into the container... and this has kinda shown me that it can be done.
    Why? Well, cause then one can stop maintaining Debian packages. Just run the entire thing in Docker.
  10. Thanks
    Elbow got a reaction from Ironman in I'm all official!   
    Hi @Ironman,
    You will find various photos etc if you look back through my posts.  I've been a pain on Powerforum I'm sure but the ou manne and others have been fantastic with advice and referring me to good guys to help me - most of whom are on this forum.
    My system has a "Renesola Replus" hybrid inverter.  These were being cleared out a few years ago at a great price.  Its a Voltronic Infinisolar OEM.  It is on the CoCT magic list of approved devices though it does not meet the latest standard so I needed to get my approval complete before the end of 2019.
    Its rated 3kVA but that really only becomes a limitation when the power is out.  When the power is present the inverter really connects the grid and essentials together and then the DC/AC inverter feeds both.  Practically that means that even on the essentials side you can exceed 3kVA.  (Obviously if the grid disappears in that state the inverter will trip so its to be avoided).
    I have 9 Canadian Solar 350W panels - I could probably have used 10 but my inverter maximum voltage is 500v and I didn't want to take a chance. So 9 means 3150kW.  COCT rules would have allowed me 3500. In practice I think 10 of these would have been fine.
    I have 2 2.4kWh Pylontech US2000B batteries.  I used 80A fuses in both + and - and also fitted a Victron battery monitor.  I probably didn't need a battery monitor since the batteries are smart but its handy at a glance to see the charge state etc.
    My inverter has a "grid" connection and an "essentials" connection.  The essentials goes to a sub-board and all my lights, my computer dedicated circuit and some plugs around the house are connected to that.  On the grid side are the high load stuff.
    I elected not to feed in to the grid.  So to get that right I fitted a Carlo Gavazzi ET112 meter and a modbus card in the inverter.  The inverter reads the nett power flow from the meter and uses that to try to balance what it feeds in so that it doesn't feed back into the grid.  After buying the ET112 I discovered it was not compatible with my inverter's modbus card - I'm stubborn and a programmer so I wrote a program that runs on a Raspberry Pi and converts the format so that the inverter is happy.
    Paperwork wise in Cape Town: It starts with a form and a basic diagram of what you intend to do.  You then get a permission to install letter (I did have to hassle them to get it).
    You then do the install, and you may "test".
    Once done you will need to have a COC for the electrical work, and there are requirements to be able to isolate, to mark main switches, and etc.  In that process I had to improve my ground for the house.  We also established that my supply from the council is out of spec - heavy load in the house and the voltage at the point of connection sags to something like 195V.  Council came and stuck a meter on the supply and didn't do anything to load it down and shrugged and said its OK and that was the end of that.
    You also need a Professional Engineer to sign off that the required automatic isolation works properly - the requirement that the inverter disconnects from the grid if the grid goes off.  He also checks grounding, isolation points, labelling and etc.  @Rautenk did that testing for me - with careful testing which is a bit tricky in the case of a hybrid.

    Then you need to do a "single line diagram" which is a sort of circuit diagram of the house electrics.  Karel gave me an example and pointed me at something called profiCAD and I did the diagram.  Took some time but was quite fun.

    Lastly, you sign a new supply contract and send all this stuff off the the council who I suppose study it carefully (?) and issue the permission to commission the system.  And you are all official.  Whether that's a good thing remains to be seen!
    I did discover that my inverter doesn't ground neutral when disconnected from the grid and supplying from solar or batteries.  So in that case neutral floats at 115 volts or so relative to ground. We've had lots of disussions here about that, especially because my inverter uses a switching inverter and not a transformer creating a question about whether its OK to connect the output neutral to ground.  But mine, at least, seems perfectly happy.  Apparently the inverter is approved, but I didn't think that was safe so I fitted a contactor that links neutral and ground if the grid drops out.
    In June I got 315kWh from the panels - so about R800 worth at the higher Cape Town rate.  425kWh in October - R1100 maybe?
     In the summer I don't have enough daytime usage to use up the available energy, and I don't have enough batteries to save it all for overnight - so sometime I'll buy another Pylontech.
    On a sunny day with lots of demand in the house I saw as much as 22.6kWh from the panels (October 25th).
    I guess I spend R65k and of course many hours.  It was a fun project so I'll pay myself R0.  So on that basis I guess it pays itself off after 6 years.
     


     
     
  11. Like
    Elbow got a reaction from Fuenkli in I'm all official!   
    Hi @Ironman,
    You will find various photos etc if you look back through my posts.  I've been a pain on Powerforum I'm sure but the ou manne and others have been fantastic with advice and referring me to good guys to help me - most of whom are on this forum.
    My system has a "Renesola Replus" hybrid inverter.  These were being cleared out a few years ago at a great price.  Its a Voltronic Infinisolar OEM.  It is on the CoCT magic list of approved devices though it does not meet the latest standard so I needed to get my approval complete before the end of 2019.
    Its rated 3kVA but that really only becomes a limitation when the power is out.  When the power is present the inverter really connects the grid and essentials together and then the DC/AC inverter feeds both.  Practically that means that even on the essentials side you can exceed 3kVA.  (Obviously if the grid disappears in that state the inverter will trip so its to be avoided).
    I have 9 Canadian Solar 350W panels - I could probably have used 10 but my inverter maximum voltage is 500v and I didn't want to take a chance. So 9 means 3150kW.  COCT rules would have allowed me 3500. In practice I think 10 of these would have been fine.
    I have 2 2.4kWh Pylontech US2000B batteries.  I used 80A fuses in both + and - and also fitted a Victron battery monitor.  I probably didn't need a battery monitor since the batteries are smart but its handy at a glance to see the charge state etc.
    My inverter has a "grid" connection and an "essentials" connection.  The essentials goes to a sub-board and all my lights, my computer dedicated circuit and some plugs around the house are connected to that.  On the grid side are the high load stuff.
    I elected not to feed in to the grid.  So to get that right I fitted a Carlo Gavazzi ET112 meter and a modbus card in the inverter.  The inverter reads the nett power flow from the meter and uses that to try to balance what it feeds in so that it doesn't feed back into the grid.  After buying the ET112 I discovered it was not compatible with my inverter's modbus card - I'm stubborn and a programmer so I wrote a program that runs on a Raspberry Pi and converts the format so that the inverter is happy.
    Paperwork wise in Cape Town: It starts with a form and a basic diagram of what you intend to do.  You then get a permission to install letter (I did have to hassle them to get it).
    You then do the install, and you may "test".
    Once done you will need to have a COC for the electrical work, and there are requirements to be able to isolate, to mark main switches, and etc.  In that process I had to improve my ground for the house.  We also established that my supply from the council is out of spec - heavy load in the house and the voltage at the point of connection sags to something like 195V.  Council came and stuck a meter on the supply and didn't do anything to load it down and shrugged and said its OK and that was the end of that.
    You also need a Professional Engineer to sign off that the required automatic isolation works properly - the requirement that the inverter disconnects from the grid if the grid goes off.  He also checks grounding, isolation points, labelling and etc.  @Rautenk did that testing for me - with careful testing which is a bit tricky in the case of a hybrid.

    Then you need to do a "single line diagram" which is a sort of circuit diagram of the house electrics.  Karel gave me an example and pointed me at something called profiCAD and I did the diagram.  Took some time but was quite fun.

    Lastly, you sign a new supply contract and send all this stuff off the the council who I suppose study it carefully (?) and issue the permission to commission the system.  And you are all official.  Whether that's a good thing remains to be seen!
    I did discover that my inverter doesn't ground neutral when disconnected from the grid and supplying from solar or batteries.  So in that case neutral floats at 115 volts or so relative to ground. We've had lots of disussions here about that, especially because my inverter uses a switching inverter and not a transformer creating a question about whether its OK to connect the output neutral to ground.  But mine, at least, seems perfectly happy.  Apparently the inverter is approved, but I didn't think that was safe so I fitted a contactor that links neutral and ground if the grid drops out.
    In June I got 315kWh from the panels - so about R800 worth at the higher Cape Town rate.  425kWh in October - R1100 maybe?
     In the summer I don't have enough daytime usage to use up the available energy, and I don't have enough batteries to save it all for overnight - so sometime I'll buy another Pylontech.
    On a sunny day with lots of demand in the house I saw as much as 22.6kWh from the panels (October 25th).
    I guess I spend R65k and of course many hours.  It was a fun project so I'll pay myself R0.  So on that basis I guess it pays itself off after 6 years.
     


     
     
  12. Like
    Elbow reacted to plonkster in I'm all official!   
    It has a North facing roof. My wife likes the house for other reasons (of course), but when I got there I first looked for a North facing roof (and noted the presence of a shadow-throwing chimney and the location of the pool heating mats... out of the way by the looks of it). Then I went hunting for the distribution board and noted that it apparently has extra space in it (which is remarkable for 1970s houses in Heldervue). Might have happened when the AirBnBs in the back were added a few years ago. Finally, I decided the inverter and batteries goes in the laundry room this time... and bought a good secondhand server case for that purpose. Mean while the wife is buying things to get the AirBnBs up and running... so now there is no space for my car in the garage 🙂
    I hate moving, but there remains an element of excitement to it!
  13. Like
    Elbow got a reaction from Carl in I'm all official!   
    Yay.  All official!
    Thank you to @Rautenk, @Mike, @Carl, @Jaco de Jongh, and tons of advice from the ou manne of the forum and lots of others besides.
    What an interesting project - I learned a lot in the process and so far not a single shock!
    On a day when we face Stage 6 shedding I feel like very clever to have  this system in the house!
    Thanks,
    @Elbow / Steve
     
  14. Like
    Elbow got a reaction from Energy in I'm all official!   
    Yay.  All official!
    Thank you to @Rautenk, @Mike, @Carl, @Jaco de Jongh, and tons of advice from the ou manne of the forum and lots of others besides.
    What an interesting project - I learned a lot in the process and so far not a single shock!
    On a day when we face Stage 6 shedding I feel like very clever to have  this system in the house!
    Thanks,
    @Elbow / Steve
     
  15. Like
    Elbow got a reaction from Jaco de Jongh in I'm all official!   
    Yay.  All official!
    Thank you to @Rautenk, @Mike, @Carl, @Jaco de Jongh, and tons of advice from the ou manne of the forum and lots of others besides.
    What an interesting project - I learned a lot in the process and so far not a single shock!
    On a day when we face Stage 6 shedding I feel like very clever to have  this system in the house!
    Thanks,
    @Elbow / Steve
     
  16. Thanks
    Elbow reacted to Jaco de Jongh in Yeah batteries   
    I can currently offer fairly good prices on batteries, we will sort you out quickly................. 😜
  17. Haha
    Elbow got a reaction from Gerlach in Yeah batteries   
    So I feel a bit self-conscious in the road, but shew it's nice to have the batteries with the load shedding.  
    We hardly notice the power going out - just the oven we have to think about.
     
  18. Like
    Elbow reacted to plonkster in After shedding mains frequency out of range   
    Voltronic Infinisolar.
  19. Like
    Elbow got a reaction from Clint in Newbie-ish   
    Mad Mike sounds right.  Come on, don’t tease us, let’s see photos of this home made lithium battery.
    its a 24v setup sound like, if you have 18650s in 7S setup?
  20. Thanks
    Elbow reacted to plonkster in Did I do you wrong (Or Right)?   
    Another thumbs-up. The pricing on- and shipping of the PV modules and mounting hardware (two separate transactions) was impressively affordable, so much that it made no sense for me to go rent a trailer and DIY as I always do. Except for that time you went and fell of a ladder and scared the cr*p out of all of us... I can't fault you 😛
     
  21. Like
    Elbow got a reaction from plonkster in Statistics after power outage   
    Interesting ‘cos for me it’s the batteries that struggle to earn their keep.
    My 9 350w panels - R25k maybe - make me about 10-12kwh per day on a sunny or mostly sunny winter’s day.  Monitoring says 250kwh in the last month or R580 of electricity by your price.  (Actually it’s more since for me it comes off the >600kwh coct rate).
    Very naive calc says they pay back the capital in 43 months.
    Very naive of course since the inverter, install and etc also had to be paid for.  But they are costs whether we talk about a solar PV install or a ups install.  My inverter and yours are hybrid so they do both roles.
    It will be more power generated in the summer assuming I have the consumption.
    By comparison the batteries, which cost about the same, can only "load shift" say 3.3kwh (70% of 4.8 capacity) so sunshine permitting they can help me get up to a an extra 100kwh in a month or R232.  107 months to earn back the cost with the same quick and dirty sum.
    in practice they don’t always recharge fully since there isn’t always "spare" sun in the day.  So then they are less effective.
    But the same capital gets me twice the return when spent on panels as compared to batteries.
    For me the panels are aimed at saving on the council electricity bill and the batteries are mainly there to help if we get into shedding.
     
     
  22. Like
    Elbow got a reaction from root in Statistics after power outage   
    Interesting ‘cos for me it’s the batteries that struggle to earn their keep.
    My 9 350w panels - R25k maybe - make me about 10-12kwh per day on a sunny or mostly sunny winter’s day.  Monitoring says 250kwh in the last month or R580 of electricity by your price.  (Actually it’s more since for me it comes off the >600kwh coct rate).
    Very naive calc says they pay back the capital in 43 months.
    Very naive of course since the inverter, install and etc also had to be paid for.  But they are costs whether we talk about a solar PV install or a ups install.  My inverter and yours are hybrid so they do both roles.
    It will be more power generated in the summer assuming I have the consumption.
    By comparison the batteries, which cost about the same, can only "load shift" say 3.3kwh (70% of 4.8 capacity) so sunshine permitting they can help me get up to a an extra 100kwh in a month or R232.  107 months to earn back the cost with the same quick and dirty sum.
    in practice they don’t always recharge fully since there isn’t always "spare" sun in the day.  So then they are less effective.
    But the same capital gets me twice the return when spent on panels as compared to batteries.
    For me the panels are aimed at saving on the council electricity bill and the batteries are mainly there to help if we get into shedding.
     
     
  23. Like
    Elbow got a reaction from Fuenkli in Statistics after power outage   
    Interesting ‘cos for me it’s the batteries that struggle to earn their keep.
    My 9 350w panels - R25k maybe - make me about 10-12kwh per day on a sunny or mostly sunny winter’s day.  Monitoring says 250kwh in the last month or R580 of electricity by your price.  (Actually it’s more since for me it comes off the >600kwh coct rate).
    Very naive calc says they pay back the capital in 43 months.
    Very naive of course since the inverter, install and etc also had to be paid for.  But they are costs whether we talk about a solar PV install or a ups install.  My inverter and yours are hybrid so they do both roles.
    It will be more power generated in the summer assuming I have the consumption.
    By comparison the batteries, which cost about the same, can only "load shift" say 3.3kwh (70% of 4.8 capacity) so sunshine permitting they can help me get up to a an extra 100kwh in a month or R232.  107 months to earn back the cost with the same quick and dirty sum.
    in practice they don’t always recharge fully since there isn’t always "spare" sun in the day.  So then they are less effective.
    But the same capital gets me twice the return when spent on panels as compared to batteries.
    For me the panels are aimed at saving on the council electricity bill and the batteries are mainly there to help if we get into shedding.
     
     
  24. Like
    Elbow got a reaction from Riaanh in Statistics after power outage   
    Interesting ‘cos for me it’s the batteries that struggle to earn their keep.
    My 9 350w panels - R25k maybe - make me about 10-12kwh per day on a sunny or mostly sunny winter’s day.  Monitoring says 250kwh in the last month or R580 of electricity by your price.  (Actually it’s more since for me it comes off the >600kwh coct rate).
    Very naive calc says they pay back the capital in 43 months.
    Very naive of course since the inverter, install and etc also had to be paid for.  But they are costs whether we talk about a solar PV install or a ups install.  My inverter and yours are hybrid so they do both roles.
    It will be more power generated in the summer assuming I have the consumption.
    By comparison the batteries, which cost about the same, can only "load shift" say 3.3kwh (70% of 4.8 capacity) so sunshine permitting they can help me get up to a an extra 100kwh in a month or R232.  107 months to earn back the cost with the same quick and dirty sum.
    in practice they don’t always recharge fully since there isn’t always "spare" sun in the day.  So then they are less effective.
    But the same capital gets me twice the return when spent on panels as compared to batteries.
    For me the panels are aimed at saving on the council electricity bill and the batteries are mainly there to help if we get into shedding.
     
     
  25. Thanks
    Elbow got a reaction from Jaco de Jongh in Did I do you wrong (Or Right)?   
    Yes, Jaco supplied me with panels and built a combiner box and etc for my project at home.  Great prices and including arranging shipping it to me in Cape Town.  Falling off a roof in the middle of our transaction and ending up in hospital did delay things a little, obviously, but even with that going down he kept in contact and delivered that combiner box first thing when he got home.
    Great service from a top bloke. 
    Who I hope is now fully recovered!

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