Solar panel production figures

katie279 said:
It was a terrible day - ferrying kids around and got alert to say batteries charged, cars charged, hot water at max temp and so it was........... exporting. :eek:

I even had a 3d printer, washing machine and dishwasher running.... Gonna need to sort it out!
Click to expand...

I’m having some issues with my 3D printer and my new system…

The printer is big, and it has a mains powered bed that draws 1000w when turned on… when it reaches temp though it goes into a PID loop to maintain temp which basically involves very fast switching on and off of the mains relay that supplies the bed.

Assuming I haven’t yet reached the point where the batteries are full and I’m exporting a sizeable chunk, my inverter loses the plot at this point - there’s always a short delay as it senses demand and ramps up, but it cannot hope to react quick enough to deal with the PID loop turning on and off the 1000W load so rapidly… the net result is that I somehow manage to both export and import energy while the printer is running (immediate demand supplied by grid, inverter ramps up, load disappears, inverter dumps excess into grid until it ramps down).

It’s quite annoying - don’t suppose you have similar issues?

I’ve been wondering whether adding some capacitors immediately prior to the bed relay might smooth out the power draw.
 
Last edited:
Zeeflyboy said:
I’m having some issues with my 3D printer and my new system…

The printer is big, and it has a mains powered bed that draws 1000w when turned on… when it reaches temp though it goes into a PID loop to maintain temp which basically involves very fast switching on and off of the mains relay that supplies the bed.

Assuming I haven’t yet reached the point where the batteries are full and I’m exporting a sizeable chunk, my inverter loses the plot at this point - there’s always a short delay as it senses demand and ramps up, but it cannot hope to react quick enough to deal with the PID loop turning on and off the 1000W load so rapidly… the net result is that I somehow manage to both export and import energy while the printer is running (immediate demand supplied by grid, inverter ramps up, load disappears, inverter dumps excess into grid until it ramps down).

It’s quite annoying - don’t suppose you have similar issues?

I’ve been wondering whether adding some capacitors immediately prior to the bed relay might smooth out the power draw.
Click to expand...

Hello, no I don't - sounds very strange! I've got two printers - one 470cm x 470cm (so very large indeed) and the other 220x220, so even with both working it doesn't have this effect. What 3d printer have you got?
My draw is pretty consistent with slight fluctuations once I hit temp, so this is probably part of the problem. As you say some sort of capacitor could help, but feels a bit industrial!

On the other side, I'm not convinced my inverter would struggle with this either - have you checked the settings there? (wondering if you can tweak the response time to household draw to ensure it is longer than the cycling on your printer?

Regardless, it does feel like there should be some sort of software solution before having to resort to hardware fixes? Your printer obviously doesn't need to cycle power like you're describing, it could obviously stabilise the draw for the same effect.
 
Ron-ski said:
Been a bad day here to, cloudy all day, only generated 6.7kWh which has basically covered daytime use, battery is at 3%. Weather looks bad up to the 18 March, which is as far as the forecast goes, rain most days :(

Low battery warning just come in.
Click to expand...

Yes at this rate Feb will turn out to be a better month! Still now the sun is higher even with the dull grey days it's still generating enough to take the baseload at home easily, and trickle charge the battery. I mean yesterday was dull dull dull, yet we barely spent £3 on electricity so it's not too bad really,.

Ron-ski said:
@katie279 had all the sun today.
Click to expand...

What's new? :D
 
katie279 said:
Hello, no I don't - sounds very strange! I've got two printers - one 470cm x 470cm (so very large indeed) and the other 220x220, so even with both working it doesn't have this effect. What 3d printer have you got?
My draw is pretty consistent with slight fluctuations once I hit temp, so this is probably part of the problem. As you say some sort of capacitor could help, but feels a bit industrial!

On the other side, I'm not convinced my inverter would struggle with this either - have you checked the settings there? (wondering if you can tweak the response time to household draw to ensure it is longer than the cycling on your printer?

Regardless, it does feel like there should be some sort of software solution before having to resort to hardware fixes? Your printer obviously doesn't need to cycle power like you're describing, it could obviously stabilise the draw for the same effect.
Click to expand...

It’s a rat rig v-core 400x400mm… it is fairly unusual in having such a powerful mains powered heater, which probably works against it here as the heater is so powerful that it only needs to be on very briefly once up to temp to maintain. If it were weaker then it would have to spend more time turned on to maintain the temp if you get me.

Bang bang rather than PID would probably make the power draw more predictable, but also bed temp less stable and possibly introduce z artefacts. I was wondering about maybe drilling a hole and adding a thermistor actually inside of the machined aluminium bed (currently the thermistor is on the underside and part of the bed heater) which would probably make the temperature readings a bit more stable and maybe slow down the PID loop.

Inverter is a Solis hybrid, can’t see anywhere to adjust that would help in that regard.

I’ll continue to have a play and see what I can do to stabilise things!
 
Last edited:
Freefaller said:
Yes at this rate Feb will turn out to be a better month! Still now the sun is higher even with the dull grey days it's still generating enough to take the baseload at home easily, and trickle charge the battery. I mean yesterday was dull dull dull, yet we barely spent £3 on electricity so it's not too bad really,.

What's new? :D
Click to expand...
I just checked my panels and they were generating 7.3kw of energy - awesome sauce!
 
Zeeflyboy said:
It’s a rat rig v-core 400x400mm… it is fairly unusual in having such a powerful mains powered heater, which probably works against it here as the heater is so powerful that it only needs to be on very briefly once up to temp to maintain. If it were weaker then it would have to spend more time turned on to maintain the temp if you get me.
Click to expand...
Yes, I think mine is 750W on larger printer, but as I say don't have these problems.
Zeeflyboy said:
Bang bang rather than PID would probably make the power draw more predictable, but also bed temp less stable and possibly introduce z artefacts. I was wondering about maybe drilling a hole and adding a thermistor actually inside of the machined aluminium bed (currently the thermistor is on the underside and part of the bed heater) which would probably make the temperature readings a bit more stable and maybe slow down the PID loop.

Inverter is a Solis hybrid, can’t see anywhere to adjust that would help in that regard.

I’ll continue to have a play and see what I can do to stabilise things!
Click to expand...

Thinking more laterally - what bed are you using? Ripped out my standard bed almost immediately and got a flexible pei sheet one which is much quicker to heat and everything sticks hunky dory to it regardless of temp.

Not sure I follow why z artifacts would occur as a result of bed heating reducing? Surely just a first layer issue?

Assume your heating element isn't a variable component? (ie put 50% power through it and heat more steadily rather than looping large bursts of draw) - lower wattage as per Ron-ski might be the fall back if not possible
 
Last edited:
Managed 12.85kWh today.

Was nice up to about 10:15 then came over cloudy, if look on my VRM you can actually tell when it got cloudy, as the east and west arrays started generating the same power - there was barely any separation between the lines on the graph.
 
You must log in or register to reply here.
Back
Top Bottom