Anyone run solar power for their shaping machine? I have the opportunity to get a good machine for relatively cheap but my property is limited by being off grid without access to power lines. I’m wondering if anyone else has a small factory running 100% on solar and if it works well for them.
I’m lucky to be in Hawaii where there is an abundance of sunlight and do not want to run a generator regularly (though I’m sure I will need as a backup)
Any input is appreciated
-Coat Hanger
Well first you’ll have to figure out how much power (Watts) you can reliably source with your panels in your location and in which timeframe.
Then contact a machine builder and ask the power consumption, they should be able to provide you this info.
Based on these numbers you can figure out whether it would be possible.
Later you can start to figure out what kind of battery (or supercap) system you need to handle to transients.
Last thing you want to have happening is the system restarting/shutting down halfway a job.
Thanks for the reply Hans. I contacted a couple machine manufacturers and couldn’t get a hard number out of them on power consumption which struck me as strange.
I would build a system to suit the consumption need which is going to make it difficult without that amp/watts draw of the machine.
hoping to get anyone’s feedback if they run a system on all solar before diving over the deepend
I would determine the amperage of the exact system (axis drive motors, controller, spindle, PC, monitor) that you intend to use-another make or model may not be the same.
Clamp meter or Killa-watt meter while the machine is running.
Short of that you could look up each piece on the interwebs and then total it all together and add enough for a light and a fan.
There will be some loss if you need to invert DC to AC.
How many boards an hour? How many a day? How much time on the PC before you turn the machine loose? Dust collection? Vacuum hold downs?
I have thought about it for a shaping shed to run planer and lights but have not executed.
Would love to see it up and running when you get that far!
If you can find the max power ratings for the spindle and stepper motors, you’ll be very close to the peak power consumption.
If the companies can’t provide you that, I wouldn’t even think about buying their machine.
The electronics should only consume a fraction of that and the machine will never operate at max rated power, so you should be safe using that number.
As a controlling PC, I’d recommend using a laptop as it comes with batteries (one less system to worry about).
Anyway the max rated powers will give you a first idea.
Any idea if shaping machines use 120 or 220 volts AC?
If it’s 120, do they require 20 amp socket, or a 15? On a 20amp socket in the USA the is prong on the left has a 90 degree tab to prevent it from being inserted into a 15 amp socket.
20 amps, times 120 volts, is 2400 watts.
While at noon, one can expect a little over 80% of their solar panel’s rating, depending on how hot they are, and the length and thickness of their wiring from panel to charge controller, they also have to figure in the inverter is likely no more than 85% efficient, when it is in its sweet spot of efficiency.
Pure sine wave inverters are more expensive than modified square wave inverters, and usually less efficient than them. Pure sine wave is often required when electronics/motors are involved.
If the batteries were depleted overnight at all, or supplementing the solar’s reduced wattage later afternoon or earlier morning, then the solar system will not only have to power the inverter to run the machine, but ALSO recharge the batteries. New healthy Lead acid batteries are pretty efficient at accepting charge upto ~80% stste of charge, but from 80 to 100% SOC it becomes less and less efficient, and they need to be returned to 100% as often as possible or they will die prematurely from sulfation.
80% to 100% SOC on lead acid batteries, cannot be achieved in less than 3.5 hours, assuming that 14.4 to 14.8v can be held at the battery terminals that entire time. Lesser voltages increase time, less healthy batteries require more time, batteries that accumulated more PSOC cycles since last true full charge, require more time.
Lead acid batteries, whether flooded, AGM or GEL, if they dont get truly fully charged often, walk down in capacity. Starting a discharge cycle before the battery has been returned to a true full state of charge, or very close to that ideal, is called a partial state of charge (PSOC). 7 PSOC cycles in a row will have the total battery capacity reduced significantly, until the true full charge is achieved. The batteries are basically punch drunk. If the full charge is not achieved after 7 to 10 PSOC cycles the lost capacity/performance, is likely lost forever, to some degree.
The true full charge after many accumulated PSOC cycles, takes significantly longer, and requires a charge controller which can actually hold that high charging voltage for the time required to attain maximum specific gravity on all cells. Achieving max SG is the benchmark for a true full charge of lead acid batteries, and indicates the battery has been charged to the maximum remaining capacity of the batteries, at that stage in their life, which is likely significantly lower than when they were new, depending on their age, and treatment to that point.
When flooded batteries are forced into to lots of PSOC cycling, the true full charge likely cannot occur unless there is an intentional overcharge, bringing the batteries to as high as 16.2v. This ‘equalizing’ voltage can be damaging to anything the batteries are powering, meaning the inverter has to be shut off and perhaps even disconnected. An EQ charge needs some careful monitoring to prevent battery overheating, and a minimum of controlled overcharge as the process itself is abusive and should be done for no longer than required.
Flooded batteries when charging and attaining ~14.2v or higher, will be making lots of oxygen, hydrogen and taking a carcinogenic sulfuric acid mist with them while they escape the batteries. @16.2v the amount of gas produced is many fold that at 14.2v. flooded lead acid batteries regularly deeply cycled, generally need to be brought to 14.4 to 14.8v for several hours to reach true full charge and stave off premature capacity loss. If performing an EQ charge, they need to be held at 14.4 to 14.8 for a few hours before initiating the 15.5 to 16.2v EQ charge.
Lead acid batteries, the ‘rule of thumb’ is also to not discharge them more than 50%. If they are drawn below this then a prompt and true full charge becomes even more important. Not low and slow over a few days, but true full charge with relatively high amperage and true full achieved quickly
Lifepo4 batteries are superior in many ways, but $$$$ and have many other considerations to keep them safe in actual use, as one overcharge or overdepletion can kill them.
One more factor in determining battery capacity required, is the peukert effect. This basically says the higher the load on teh battery, the less capacity the battery has to give.
A 100 amp hour capacity newish, healthy, fully charged battery, can support a 5 amp load for 20 hours before it is considered 100% discharged.
a 100 amp hour battery, however, cannot power a 20 amp load for 5 hours. under a 20 amp load the 100Ah lead acid battery only has about 60 amp hours to give, and would likely be fully depleted in under 3 hours.
Lifepo4 is much less affected by Peukert.
Lots of RV’ers and Boater and perhaps some offgrid guys dream of being able to run an Air conditioner off of battery power and solar. They usually need a LOT of battery, as much solar as they can fit and more or other charging sources to assist, and increased insulation, and most still can’t reliably power it overnight, all night, in hot temperatures. The off grid guys have an advantage in battery weight and solar panel area, over the RVer and boaters.
It’s not impossible, its just that a good amount of overhead needs to be factored in, and that overhead shrinks with high clouds and aging batteries, and even as the solar panels age, their output decreases.
A lot of those seeking to power high wattage items for high duration, once they have all the numbers run, start thinking about how to better soundproof a Generator and how much gas they can run through it before their solar starts to pay for itself.
One other factor is motor start up surge. for example the compressor on a fridge might draw over 1200 watts for a second or 3 when it starts, then running wattage thereafter is 120 watts. Inverters and generators will list a surge wattage, usually market around that surge rating, but how long can it maintain that surge wattage? Very few market this number.
Lots of people trying to power residential refrigerators on battery power, find that their residential fridge which draws only 65 watts when running, needs a 1200 watt inverter with a 2000+ watt surge rating, just to handle the start up surge of the compressor motor.
As said the max potential draw of a shaping machine is not the amount it will ALWAYS draw, but how much average it does draw, and for how long, is a HUGE factor. Until it is known how much it will draw, in your usage, how much solar and battery you need is just a guess.
Might want to do some pricing of GC-2 or L-16 batteries in your area, which are 6v batteries, although the l-16s can come in 2 volt versions, requiring 6 of them in series to make 12v.
That generator at the edge of the property in a sound enclosure might look more and more choiceworthy if the shaping machine is an AMPwhore.
Check with a guy named Marco Mangelsdorf. He is one the guys that has been doing solar PV in Hawaii longer than anyone else.
So I was able to get some information from 3DM. Max draw would be 30amps for fire up and around 12-15amps running on a heavy load. Thats including vacuum system as well (necessary) though I don’t know if it includes operating computer. That’s running 3 phase 210-218V power… that’s a lot of watts.
im trying to check in with some other machine manufacturers as I do not have access to power poles so I cannot do a hybrid system and I know some others do 110v and non-three phase systems which would be more economical of a PV system to build.
i appreciate everyone’s input and will update with information I find
Just FYI you can reduce the power consumption by running at lower feedrates and spindle rpms.
You received the max power ratings which is not the same as the “mean power”. Using a battery pack (and maybe some supercaps), handling these peaks should not be an issue. But these numbers are an important starting point.
Just my humble opinion as a former electronics technician. At its heart a shaping machine is a computer. More than anything you want clean stable power. Would suck to kill the machine, have un-neccessary down time or expensive breakdowns because your power supply was iffy.
That’s a good remark, but this can be fixed.
The sensitive (low-power) electronics are galvanically separated from the high power circuitry (or at least should be on any decent machine).
Therefore it is perfectly possible to feed them from a separate power source and since this part only consumes a fraction of the power, it’s easy to feed it with a small PV/battery system. However, this requires some electrical knowledge, it should be a feasible job for anyone trying to undertake this entire project.
I built the power supply on my machine to supply up to 10 amps at 70 volts. Typically it’s pulling 2-3A to run the steppers (I did the calculations a long time ago). I run off standard 240 volts / 10amp wall plug (50Hz power supply here in Aus) and step down the volts.
My cutting head runs off a standard 3HP (2100 watt) Makita router off separate power supply, but controlled by the machine’s electronics board. A spindle will probably pull more amps.
My hold down is yet another power supply running a venturi vaccuum off a standard compressor. A dedicated high volume vac pump would be a much better option.
Then there’s the computer and machine’s electronics board that pull a bit.
I used to run the whole mess on a 25 meter 10amp extension cable when my shed did not have pwoer.
As mentioned earlier, a power dip can reset your computer and confuse the electronics in the board that tells the machine what to do. Always a bugger trying to restart a job midway.
All combined I think there’s a bit of draw in the system, but maybe knowing the component parts of my system can help you guess at the power draw of the machine you are looking at.
I tripped over this post https://buildyourcnc.com/FAQ/1022
I remember doing similar calculations when I built my machine.